Hindawi Publishing CorporationOxidative Medicine and Cellular LongevityVolume 2013 Article ID 387014 9 pageshttpdxdoiorg1011552013387014
Review ArticleDNA Damage in Inflammation-Related Carcinogenesis andCancer Stem Cells
Shiho Ohnishi1 Ning Ma2 Raynoo Thanan34 Somchai Pinlaor45 Olfat Hammam6
Mariko Murata7 and Shosuke Kawanishi1
1 Faculty of Pharmaceutical Sciences Suzuka University of Medical Science Suzuka 513-8670 Mie Japan2 Faculty of Health Science Suzuka University of Medical Science Suzuka 510-0293 Mie Japan3Department of Biochemistry Faculty of Medicine Khon Kaen University Khon Kaen 40002 Thailand4Department of Parasitology Faculty of Medicine Khon Kaen University Khon Kaen 40002 Thailand5 Liver Fluke and Cholangiocarcinoma Research Center Faculty of Medicine Khon Kaen University Khon Kaen 40002 Thailand6Departments of Pathology and Urology Theodor Bilharz Research Institute Giza 12411 Egypt7 Department of Environmental and Molecular Medicine Mie University Graduate School of Medicine Tsu 514-8507 Mie Japan
Correspondence should be addressed to Shosuke Kawanishi kawanisisuzuka-uacjp
Received 2 August 2013 Accepted 20 September 2013
Academic Editor Pavel Rossner Jr
Copyright copy 2013 Shiho Ohnishi et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
Infection and chronic inflammation have been recognized as important factors for carcinogenesis Under inflammatory conditionsreactive oxygen species (ROS) and reactive nitrogen species (RNS) are generated from inflammatory and epithelial cells and resultin oxidative and nitrative DNA damage such as 8-oxo-78-dihydro-21015840-deoxyguanosine (8-oxodG) and 8-nitroguanine The DNAdamage can causemutations and has been implicated in the initiation andor promotion of inflammation-mediated carcinogenesisIt has been estimated that various infectious agents are carcinogenic to humans (IARC group 1) including parasites (Schistosomahaematobium (SH) andOpisthorchis viverrini (OV)) viruses (hepatitis C virus (HCV) human papillomavirus (HPV) and Epstein-Barr virus (EBV)) and bacteriumHelicobacter pylori (HP) SH OV HCV HPV EBV and HP are important risk factors for bladdercancer cholangiocarcinoma hepatocellular carcinoma cervical cancer nasopharyngeal carcinoma and gastric cancer respectivelyWe demonstrated that 8-nitroguanine was strongly formed via inducible nitric oxide synthase (iNOS) expression at these cancersites of patients Moreover 8-nitroguanine was formed in Oct34-positive stem cells in SH-associated bladder cancer tissues and inOct34- and CD133-positive stem cells in OV-associated cholangiocarcinoma tissues Therefore it is considered that oxidative andnitrative DNA damage in stem cells may play a key role in inflammation-related carcinogenesis
1 DNA Damage in Inflammation-RelatedCarcinogenesis
Infection and chronic inflammation have been recognized asimportant risk factors for carcinogenesis and malignancies[1ndash3] The International Agency for Research on Cancer(IARC) has estimated that approximately 18 of cancer casesworldwide are attributable to infectious diseases caused bybacteria viruses and parasites [4] The burden of cancercaused by infectious agents is shown in Table 1 Inflam-mation can be induced not only by chronic infectionbut also by many other physical chemical and immuno-logical factors [5 6] It has been estimated that chronic
inflammation accounts for approximately 25 of humancancers
Under inflammatory conditions reactive oxygen species(ROS) and reactive nitrogen species (RNS) are generatedfrom inflammatory and epithelial cells [7] ROS and RNS arecapable of causing damage to various cellular constituentssuch as nucleic acids proteins and lipids ROS are generatedfrom multiple sources including inflammatory cells car-cinogenic chemicals and their metabolites and the electrontransport chain in mitochondria [2 3] ROS can inducethe formation of oxidative DNA lesion products including8-oxo-78-dihydro-21015840-deoxyguanosine (8-oxodG) which isconsidered to be mutagenic [7 8] During DNA synthesis
2 Oxidative Medicine and Cellular Longevity
Table 1 Possible markers for cancer stem cells in inflammation-related cancer
Etiologic agentpathologic condition Associated cancer Detection of
8-nitroguanine
Possible markers for cancer stemcells related to each cause[references]
Parasites SH Bladder cancer Patients [10 11] Oct34 (patients with SH) [10]CD44v6 (patients without SH) [11]
OV Cholangiocarcinoma Hamsters [12ndash15] mdashPatients [16 17] CD133 Oct34 [17]
SH Schistosoma haematobium OV Opisthorchis viverrini HCV hepatitis C virus HBV hepatitis B virus HPV human papillomavirus EBV Epstein-Barrvirus HP Helicobacter pylori IBD inflammatory bowel diseases LP lichen planus BE Barrettrsquos esophagus DN data not shown
adenine ismisincorporated opposite 8-oxodG leading toGCto TA transversions [9]
Nitric oxide (NO) is synthesized by NO synthases Thereare three isoforms neuronal NO synthase (nNOS alsoknown as NOS1) inducible NO synthase (iNOS or NOS2)and endothelial NO synthase (eNOS or NOS3) [43 44]iNOS is activated to drastically generate NO in inflammatoryand epithelial cells under inflammatory conditions whileeNOS and nNOS are constitutively expressed and producerelatively small amounts of NO iNOS can be also upregulatedby transcription factors such as NF-120581B HIF1-120572 STAT andTNF-120572 NF-120581B plays a central role in inflammation throughits ability to induce transcription of proinflammatory genesincluding iNOS and functions as a tumor promoter ininflammation-associated cancer [45]
ExcessNOproduction plays a crucial role in an enormousvariety of pathological processes including cancer [43]NO reacts with superoxide (O
2
∙minus) to form peroxynitrite(ONOOminus) a highly reactive species causing 8-oxodG and 8-nitroguanine [46 47] The reaction of guanine with ONOOminusforms 8-nitroguanine as the major compound [46] while
adenine nitration is minor compared to its C8-oxidation[48] Akaike et al have demonstrated that 8-nitroguanine isformed via NO production associated with inflammation inmice with viral pneumonia [49] 8-Nitroguanine is consid-ered to be not only a marker of inflammation but also apotential mutagenic DNA lesion leading to carcinogenesis[50] 8-Nitroguanine formed in DNA is chemically unstableand thus can be spontaneously released resulting in theformation of an apurinic site [51] The apurinic site can forma pair with adenine during DNA synthesis leading to GC toTA transversions [52] However the discovery of translesionDNA polymerases and their role in the mutagenesis in livingcells made this paradigm rather obsolete [53 54] AP sitesare indeed mutagenic but the A-rule does not really describeits mutagenic potential Cells deficient in Rev1 and Rev3subunits of DNA polymerase 120577 were hypersensitive to nitra-tive stress and translesion DNA synthesis past apurinic sitesmediated by this polymerase might contribute to extensivepoint mutations [55] It has been reported that adenine ispreferentially incorporated opposite 8-nitroguanine duringDNA synthesis catalyzed by polymerase 120578 and 120581ΔC in
Oxidative Medicine and Cellular Longevity 3
a cell-free system suggesting that GC to TA transversionscan occur [56] In the ONOOminus-treated supF shuttle vectorwhich was replicated in host Escherichia coli cells the major-ity of mutations occurred at GC base pairs predominantlyinvolvingGC toTA transversions [57]Thus 8-nitroguanineis a potentially mutagenic DNA lesion that can participate ininitiation and promotion in infection-related carcinogenesis
Wehave investigated the formation of 8-nitroguanine and8-oxodG in various clinical specimens and animal modelsin relation to inflammation-related carcinogenesis as sum-marized in Table 1 It is noteworthy that DNA damage wasspecifically induced at sites of carcinogenesis under chronicinfection and various inflammatory conditions as reviewedpreviously [2 3] It has been estimated that 11 infectiousagents are carcinogenic to humans (Group 1) by IARC par-asites (Schistosoma haematobium (SH) Opisthorchis viver-rini (OV) and Clonorchis sinensis (CS)) viruses (hepatitisB and C virus (HBV and HCV) human papillomavirus(HPV) Epstein-Barr virus (EBV) humanT-cell lymphotrop-ic virus (HTLV-1) Kaposirsquos sarcoma herpesvirus (KSHV)and human immunodeficiency virus-1 (HIV-1)) and bac-terium Helicobacter pylori (HP) [4 58] We demonstratedthat 8-nitroguaninewas strongly formed via iNOS expressionat related cancer sites of SH OV HBV HCV HPV EBVand HP [2 3 10 11] The IARC classification of CS hasbeen recently updated from 2A to 1 so we have not yetcollected enough data for 8-nitroguanine The mechanismof carcinogenesis by HTLV-1 KSHV or HIV-1 seems notto be associative to inflammation We could not observe 8-nitroguanine in leukaemia samples from patients infectedwith HTLV-1 (data not shown) 8-Nitroguanine was alsoformed in tissues from patients with inflammatory diseasessuch as inflammatory bowel diseases (IBD) Lichen planus(LP) and Barrettrsquos esophagus (BE) [3 38] Recently wehave reported that the formation of 8-nitroguanine and8-oxodG increased significantly in the order of Barrettrsquosesophageal adenocarcinoma gt Barrettrsquos esophagus gt normaltissues Treatment of BEpatientswith proton pump inhibitors(PPIs) which is expected to reduce the risk of Barrettrsquosesophageal adenocarcinoma suppressed these DNA lesionsprobably via activation of an antioxidant enzyme Mn-SOD[38] Regarding inflammation-related carcinogenesis withoutinfection we describe the formation of 8-nitroguanine inlung tissues of mice intratracheally administered asbestos[42] although the precise mechanism of nitrative DNAdamage remains to be clarified Nitrative stress is involved inthe asbestos-derived inflammatory response via myeloperox-idase [59ndash62] that plays a significant role in asbestos-inducedcarcinogenesis [63] Interestingly immunoreactivities of 8-nitroguanine iNOS andNF-120581B significantly increased in theorder of carcinogenic potential crocidolite (blue asbestos) gtchrysotile (white asbestos) gt control [42]
On the basis of our studies various pathogenic factorsinduce inflammatory responses and the production of ROSand RNS from inflammatory and epithelial cells via iNOSexpression which is regulated by transcriptional factorsincluding NF-120581B STAT and HIF-1120572 [2 3] Oxidative andnitrative stresses cause DNA damage contributing to theaccumulation of genetic alterations in tissues throughout
the carcinogenic process Particularly 8-nitroguanine for-mation may participate in inflammation-related carcinogen-esis as a common mechanism Therefore 8-nitroguaninecould be used as a potential biomarker of inflammation-related carcinogenesis Importantly experimental evidencehas suggested that 8-nitroguanine can lead to mutationspreferentially GC to TA transversions [46 64] in additionto 8-oxodG [9 65] Indeed GC to TA transversions havebeen observed in vivo in the ras gene [66] and the p53tumor suppressor gene in lung and liver cancer [67 68]We also revealed that 8-nitroguanine and 8-oxodG wereapparently formed in adenocarcinoma caused by mutatedK-ras by using conditional transgenic mice with K-rasV11988611989712[69] 8-Nitroguanine was colocalized with iNOS NF-120581BIKK MAPK MEK and mutated K-ras suggesting thatoncogenic K-ras causes additional DNAdamage via signalingpathways involving these molecules It is noteworthy thatK-ras mutation mediates not only cell overproliferation butalso the accumulation of mutagenic DNA lesions leadingto carcinogenesis These findings imply that DNA damagemediated by ROS and RNS may participate in carcinogenesisvia activation of protooncogenes and inactivation of tumorsuppressor genes
2 Cancer Stem Cell Markers inInflammation-Related Carcinogenesis
The cancer stem cell concept is widely accepted as importantfor overcoming cancer Several studies have revealed that can-cer cells show accumulation of mutations genetic instabilityand epigenetic change suggesting that cancer is also a diseaseof genes [70]Themost important question is how to generatecancer stem cells Recently many studies have reported onthe expressions of stemness cell markers in various kindsof cancer Table 1 summarizes possible markers of cancerstem cells especially related to each inflammatory causativeagent We reported that 8-nitroguanine was strongly formedat all of these cancer sites from animals and patients withinfectious agents inflammatory diseases and exposure toasbestos Importantly we also detected colocalization of8-nitroguanine and stemness marker in infection-relatedcarcinogenesis as mentioned in the next section On thebasis of our recent studies it is considered that chronicinflammation can increase mutagenic DNA lesions throughROSRNS generation and can promote proliferation via stemcells activation for tissue regeneration This idea is alsosupported by other papers about the association of cancerstem cells with infection and inflammation [71ndash74]
3 DNA Damage and MutantStem Cells Induced bySchistosoma haematobium Infection
Chronic infection with SH is associated with urinary bladdercancer [76] Contact with contaminated freshwater is themajor risk factor for infection SH-associated bladder canceris a common malignancy especially in the Middle East andAfrica It is believed that the parasitersquos eggs in the host
4 Oxidative Medicine and Cellular Longevity
8-Nitroguanine Oct34 Merged
Nor
mal
Cysti
tis (S
H+)
Canc
er (S
H+
)Ca
ncer
(SHminus
)
Figure 1The formation of 8-nitroguanine (red) and the expression of Oct34 (green) were assessed by double immunofluorescence staining[10] In the merged image co-localization of 8-nitroguanine and Oct34 is indicated in yellow Original magnification in all pictures is 200x(SH Schistosoma haematobium) Formalin-fixed and paraffin-embedded biopsy and surgical specimens were obtained from normal subjectsand patients with SH-induced cystitis and bladder cancer Normal tissues and urinary bladder cancer tissues without SH infection wereobtained from a commercial urinary bladder tissue array (Biomaxus USA) Normal tissues with cystitis were excluded SH-egg antigens insera were detected by Sandwich ELISA assay [75] This study was performed in accordance with the Ethical Guidelines for EpidemiologicalResearch enacted by the Japanese government Deparaffinized and antigen-retrieved sections were incubated first with 5 skim milk andthen with a rabbit polyclonal anti-8-nitroguanine antibody (2 120583gmL prepared as described previously [11]) and mouse monoclonal anti-Oct34 antibody (2120583gmL Santa Cruz Biotechnology CA USA) overnight at room temperature The sections were then incubated for 3 hwith Alexa 594-labeled goat antibody against rabbit IgG and Alexa 488-labeled goat antibody against mouse IgG (each 1 400 MolecularProbes Eugene OR USA)
bladder result in irritation eventual fibrosis and chronic cys-titis leading to carcinogenesis To investigate whether oxida-tive and nitrative DNA damage participate in inflammation-related carcinogenesis we performed immunohistochemicalanalysis using bladder tissues obtained from cystitis and blad-der cancer patients infected with SH We demonstrated forthe first time that 8-nitroguanine is formed in the tumors ofbladder cancer patients with SH infection [10]The formationof 8-nitroguanine and 8-oxodG was significantly higher inbladder cancer and cystitis tissues than in normal tissuesOxidative DNA damage and SH infection were stronglycorrelated [10 77] iNOS expression was co-localized withNF-120581B in 8-nitroguanine-positive tumor cells from bladdercancer patients NF-120581B can be activated by TNF-120572 a majormediator of inflammation which has been reported toincrease in peripheral bloodmononuclear cells stimulated bySH egg antigen [78] It is reasonable to conclude that both8-nitroguanine and 8-oxodG are formed by iNOS-mediatedNO overproduction via NF-120581B activation under SH-causedchronic inflammation
A stemness marker Oct34 is generally expressed in plu-ripotent embryonic stem and germ cells [79] Expression
of Oct34 is reportedly necessary for maintaining the self-renewing cancer stem-like and chemoradioresistant proper-ties of tumorigenic stem-like cell populations [80 81] and isthus considered to play roles in the carcinogenesis processAnother stemness marker CD44 has been identified asa cell surface marker associated with cancer stem cells inseveral types of tumors [82 83] including urinary bladdercancer [84] Expression of CD44v6 a splicing variant ofCD44 is correlated with proliferation of poorly differentiatedurothelial cells and the characteristic phenotype of tumor-initiating bladder cancer stem cells [85ndash87] Our previousreports show that different risk factors induce differentlevels of expression of stemness markers in urinary bladdercarcinoma SH-induced urinary bladder cancer correlateswith the expression of Oct34 [10] while urinary bladdercancer without the infection correlates with the expressionof CD44v6 [11] Moreover 8-nitroguanine was formed inOct34-positive stem cells in SH-associated cystitis and can-cer tissues [10] as shown in Figure 1 Inflammation by SHinfection may increase the number of mutant stem cellsin which iNOS-dependent DNA damage occurs via NF-120581Bactivation leading to tumor development
Figure 2 Postulated mechanism for generating cancer stem cells by inflammation
4 DNA Damage and Mutant Stem CellsInduced by Opisthorchis viverrini Infection
Chronic infection with the liver fluke OV is associatedwith cholangiocarcinomas [58] Infection with this para-site is repeatedly caused by eating raw fish containing theinfective stage of the fluke We have demonstrated that 8-nitroguanine is formed in relation to inflammation-relatedcarcinogenesis using an animal model [12ndash15] 8-OxodGand 8-nitroguanine were formed in inflammatory cells andepithelium of bile ducts and their formation increased in amanner dependent on infection timesThe anthelmintic drugpraziquantel dramatically diminished these DNA lesions andiNOS expression in OV-infected hamsters Thus repeatedOV-infection can induce the iNOS expression in bile ductsand subsequently cause nitrative and oxidative damage tonucleic acids which may participate in cholangiocarcinoma
In our study with patients the formation of 8-oxodGand 8-nitroguanine occurred to a much greater extent incancerous tissue than in noncancerous tissue in intrahepaticcholangiocarcinoma patients indicating that these DNAlesions contribute to tumor progression [16] Our proteomicstudy showed that carbonylation of serotransferrin and heatshock protein 70 kDa protein 1 (HSP701) is significantlyassociated with poor prognoses [88] Carbonylation of pro-tein is an irreversible modification induced by oxidativestress We have proposed that carbonylations of serotrans-ferrin and HSP701 may induce oxidative stress by iron-accumulation and dysfunction of antioxidative propertyleading to increased oxidative DNA damage and progressionof cholangiocarcinoma
Recently we observed high expression and co-locali-zation of hepatocyte marker and cholangiocyte marker inOV-associated cholangiocarcinoma patients suggesting the
6 Oxidative Medicine and Cellular Longevity
involvement of stem cells in cholangiocarcinoma develop-ment [17] Cholangiocarcinoma tissues with positive stem-ness markers (CD133 or Oct34) showed significantly lowerexpression of antioxidant enzyme Mn-SOD and significantlyhigher levels of 8-oxodG 8-nitroguanine and DNA damageresponse protein 120574-H2AX Moreover CD133- and Oct34-positive cholangiocarcinoma patients had significant associa-tionswith tumor histology types tumor stage and poor prog-noses These findings suggest that CD133 and Oct34 in cho-langiocarcinoma are highly associated with formation ofDNA lesions whichmay be involved in genetic instability andlead to tumor development with aggressive clinical featuresIn our study proliferating cell nuclear antigen (PCNA)accumulated in the epithelium of bile ducts of hamsters afterrepeated OV infection supporting the hypothesis that cellproliferation is promoted by inflammation-mediated DNAdamage [14] Inflammation by OV infection may increasethe number of mutant stem cell in which oxidative stressessuch as carbonylation of proteins and oxidativeDNAdamageand cell proliferation are promoted leading to progression ofcholangiocarcinoma
5 Conclusions
Nitrative and oxidative DNA lesions with mutagenic proper-ties are formed in various types of inflammation-related can-cer tissuesWehave proposed amechanism for the generationof cancer stem cells by inflammation in Figure 2 Chronicinflammation by infectious agents inflammatory diseasesand other factors causes various types of damage to nucleicacids proteins tissue and so on via ROSRNS generationTissue injury under chronic inflammation may activate pro-genitorstem cells for regeneration In these cells ROSRNSfrom inflammation can cause multiple mutations whichmaygenerate mutant stem cells and cancer stem cells leadingto carcinogenesis Indeed 8-nitroguanine was formed instemness marker-positive cells in parasite-associated cancertissues The mechanism for generation of cancer stem cellswill be explained by our ongoing studies on the formation of8-nitroguanine in stem-like cells of target tissues associatedwith other inflammation-related cancers
Conflict of Interests
The authors declare that they have no conflict of interests
Acknowledgment
This work was supported by a grant-in-aid from theMinistryof Education Culture Sports Science and Technology ofJapan
References
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[2] S Kawanishi and Y Hiraku ldquoOxidative and nitrative DNAdamage as biomarker for carcinogenesis with special reference
to inflammationrdquo Antioxidants and Redox Signaling vol 8 no5-6 pp 1047ndash1058 2006
[3] M Murata R Thanan N Ma and S Kawanishi ldquoRole ofnitrative and oxidative DNA damage in inflammation-relatedcarcinogenesisrdquo Journal of Biomedicine and Biotechnology vol2012 Article ID 623019 11 pages 2012
[4] IARC ldquoChronic infectionsrdquo in World Cancer Report B WStewart and P Kleihues Eds pp 128ndash135 IARC Press LyonFrance 2008
[5] S P Hussain and C C Harris ldquoInflammation and canceran ancient link with novel potentialsrdquo International Journal ofCancer vol 121 no 11 pp 2373ndash2380 2007
[6] A J Schetter N H Heegaard and C C Harris ldquoInflammationand cancer interweaving microRNA free radical cytokine andp53 pathwaysrdquo Carcinogenesis vol 31 no 1 Article ID bgp272pp 37ndash49 2010
[7] H Ohshima M Tatemichi and T Sawa ldquoChemical basis ofinflammation-induced carcinogenesisrdquo Archives of Biochem-istry and Biophysics vol 417 no 1 pp 3ndash11 2003
[8] S Kawanishi Y Hiraku and S Oikawa ldquoMechanism ofguanine-specific DNA damage by oxidative stress and its rolein carcinogenesis and agingrdquoMutation Research vol 488 no 1pp 65ndash76 2001
[9] S D Bruner D P G Norman and G L Verdine ldquoStructuralbasis for recognition and repair of the endogenous mutagen 8-oxoguanine in DNArdquo Nature vol 403 no 6772 pp 859ndash8662000
[10] N Ma R Thanan H Kobayashi et al ldquoNitrative DNA damageand Oct34 expression in urinary bladder cancer with Schis-tosoma haematobium infectionrdquo Biochemical and BiophysicalResearch Communications vol 414 no 2 pp 344ndash349 2011
[11] R Thanan M Murata N Ma et al ldquoNuclear localization ofCOX-2 in relation to the expression of stemness markers inurinary bladder cancerrdquo Mediators of Inflammation vol 2012Article ID 165879 8 pages 2012
[12] S Pinlaor Y Hiraku P Yongvanit et al ldquoiNOS-dependentDNA damage via NF-120581B expression in hamsters infected withOpisthorchis viverrini and its suppression by the antihelminthicdrug praziquantelrdquo International Journal of Cancer vol 119 no5 pp 1067ndash1072 2006
[13] S Pinlaor Y Hiraku NMa et al ldquoMechanism of NO-mediatedoxidative and nitrative DNA damage in hamsters infectedwithOpisthorchis viverrini a model of inflammation-mediatedcarcinogenesisrdquo Nitric Oxide vol 11 no 2 pp 175ndash183 2004
[14] S Pinlaor N Ma Y Hiraku et al ldquoRepeated infection withOpisthorchis viverrini induces accumulation of 8-nitroguanineand 8-oxo-78-dihydro-21015840-deoxyguanine in the bile duct ofhamsters via inducible nitric oxide synthaserdquo Carcinogenesisvol 25 no 8 pp 1535ndash1542 2004
[15] S Pinlaor P Yongvanit YHiraku et al ldquo8-Nitroguanine forma-tion in the liver of hamsters infectedwithOpisthorchis viverrinirdquoBiochemical and Biophysical Research Communications vol 309no 3 pp 567ndash571 2003
[16] S Pinlaor B Sripa N Ma et al ldquoNitrative and oxidative DNAdamage in intrahepatic cholangiocarcinoma patients in relationto tumor invasionrdquo World Journal of Gastroenterology vol 11no 30 pp 4644ndash4649 2005
[17] R Thanan C Pairojkul S Pinlaor et al ldquoInflammation-related DNA damage and expression of CD133 and Oct34 incholangiocarcinoma patients with poor prognosisrdquo Free RadicalBiology amp Medicine 2013
Oxidative Medicine and Cellular Longevity 7
[18] S Horiike S Kawanishi M Kaito et al ldquoAccumulation of 8-nitroguanine in the liver of patients with chronic hepatitis CrdquoJournal of Hepatology vol 43 no 3 pp 403ndash410 2005
[19] N Ali H Allam R May et al ldquoHepatitis C virus-inducedcancer stem cell-like signatures in cell culture and murinetumor xenograftsrdquo Journal of Virology vol 85 no 23 pp 12292ndash12303 2011
[20] K Machida H Tsukamoto H Mkrtchyan et al ldquoToll-likereceptor 4 mediates synergism between alcohol and HCVin hepatic oncogenesis involving stem cell marker NanogrdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 106 no 5 pp 1548ndash1553 2009
[21] Y Hiraku T Tabata N Ma M Murata X Ding and SKawanishi ldquoNitrative and oxidative DNA damage in cervicalintraepithelial neoplasia associatedwith humanpapilloma virusinfectionrdquo Cancer Science vol 98 no 7 pp 964ndash972 2007
[22] S-K Kim H-S Shim K-G Lee H-J An K-R Lee andN-H Cho ldquoGlassy cell carcinoma predominantly commits toa squamous lineage and is strongly associated with high-risktype human papillomavirus infectionrdquo International Journal ofGynecological Pathology vol 28 no 4 pp 389ndash395 2009
[23] S Regauer and O Reich ldquoCK17 and p16 expression pat-terns distinguish (atypical) immature squamous metaplasiafrom high-grade cervical intraepithelial neoplasia (CIN III)rdquoHistopathology vol 50 no 5 pp 629ndash635 2007
[24] W-K Liu Y-L Chu F Zhang et al ldquoThe relationship betweenHPV16 and expression of CD44v6 nm23H1 in esophagealsquamous cell carcinomardquo Archives of Virology vol 150 no 5pp 991ndash1001 2005
[25] D Liu P Zhou L Zhang et al ldquoHDAC1DNMT3A-containingcomplex is associated with suppression of Oct4 in cervicalcancer cellsrdquo Biochemistry vol 77 no 8 pp 934ndash940 2012
[26] N Ma M Kawanishi Y Hiraku et al ldquoReactive nitrogenspecies-dependent DNA damage in EBV-associated nasopha-ryngeal carcinoma the relation to STAT3 activation and EGFRexpressionrdquo International Journal of Cancer vol 122 no 11 pp2517ndash2525 2008
[27] Q-L Kong L-J Hu J-Y Cao et al ldquoEpstein-barr virus-encoded LMP2A induces an epithelialmdashmesenchymal transi-tion and increases the number of side population stem-likecancer cells in nasopharyngeal carcinomardquo PLoS Pathogens vol6 no 6 Article ID e1000940 2010
[28] A Dutton C B Woodman M B Chukwuma et al ldquoBmi-1 isinduced by the Epstein-Barr virus oncogene LMP1 and regulatesthe expression of viral target genes inHodgkin lymphoma cellsrdquoBlood vol 109 no 6 pp 2597ndash2603 2007
[29] N Ma Y Adachi Y Hiraku et al ldquoAccumulation of 8-nitroguanine in human gastric epithelium induced by Heli-cobacter pylori infectionrdquo Biochemical and Biophysical ResearchCommunications vol 319 no 2 pp 506ndash510 2004
[30] M Katsurahara Y Kobayashi M Iwasa et al ldquoReactivenitrogen species mediate DNA damage in helicobacter pylori-infected gastric mucosardquo Helicobacter vol 14 no 6 pp 552ndash558 2009
[31] Y Fujii K Yoshihashi H Suzuki et al ldquoCDX1 confers intestinalphenotype on gastric epithelial cells via induction of stemness-associated reprogramming factors SALL4 and KLF5rdquo Proceed-ings of the National Academy of Sciences of USA vol 109 no 50pp 20584ndash10589 2012
[32] J M Noto T Khizanishvili R Chaturvedi et al ldquoHelicobacterpylori promotes the expression of Kruppel-like factor 5
a mediator of carcinogenesis in vitro and in vivordquo PLoS Onevol 8 no 1 Article ID e54344 2013
[33] T Uehara D Ma Y Yao et al ldquoH pylori infection is associatedwith DNA damage of Lgr5-positive epithelial stem cells in thestomach of patients with gastric cancerrdquo Digestive Diseases andSciences vol 58 no 1 pp 140ndash149 2013
[34] X Ding Y Hiraku N Ma et al ldquoInducible nitric oxidesynthase-dependent DNA damage in mouse model of inflam-matory bowel diseaserdquoCancer Science vol 96 no 3 pp 157ndash1632005
[35] P Chaiyarit N Ma Y Hiraku et al ldquoNitrative and oxidativeDNA damage in oral lichen planus in relation to human oralcarcinogenesisrdquoCancer Science vol 96 no 9 pp 553ndash559 2005
[36] L Ma H Wang H Yao L Zhu W Liu and Z Zhou ldquoBmi1expression in oral lichen planus and the risk of progression tooral squamous cell carcinomardquo Annals of Diagnostic Pathologyvol 17 no 4 pp 327ndash330 2013
[37] A Bose M T Teh I L Hutchison H Wan I M Leigh andA Waseem ldquoTwo mechanisms regulate keratin K15 expressionin keratinocytes role of PKCAP-1 and FOXM1 mediatedsignallingrdquo PLoS One vol 7 no 6 Article ID e38599 2012
[38] RThanan NMa K Iijima et al ldquoProton pump inhibitors sup-press iNOS-dependent DNA damage in Barrettrsquos esophagus byincreasing Mn-SOD expressionrdquo Biochemical and BiophysicalResearch Communications vol 421 no 2 pp 280ndash285 2012
[39] J Mendelson S Song Y Li et al ldquoDysfunctional transform-ing growth factor-120573 signaling with constitutively active notchsignaling in Barrettrsquos esophageal adenocarcinomardquo Cancer vol117 no 16 pp 3691ndash3702 2011
[40] J Ahmad K Arthur P Maxwell et al ldquoRe grotenhuis et alBarrettrsquos oesophageal adenocarcinoma encompasses tumour-initiating cells that do not express common cancer stem cellmarkers J Pathol 2010 221 379ndash389rdquo Journal of Pathology vol224 no 1 pp 143ndash145 2011
[41] Y V Bobryshev A K Freeman N K Botelho D Tran AJ M Levert-Mignon and R V N Lord ldquoExpression of theputative stem cell marker Musashi-1 in Barrettrsquos esophagus andesophageal adenocarcinomardquoDiseases of the Esophagus vol 23no 7 pp 580ndash589 2010
[42] Y Hiraku S Kawanishi T Ichinose and M Murata ldquoThe roleof iNOS-mediated DNA damage in infection- and asbestos-induced carcinogenesisrdquo Annals of the New York Academy ofSciences vol 1203 pp 15ndash22 2010
[43] D Fukumura S Kashiwagi and R K Jain ldquoThe role of nitricoxide in tumour progressionrdquoNature Reviews Cancer vol 6 no7 pp 521ndash534 2006
[44] P K Lala and C Chakraborty ldquoRole of nitric oxide in carcino-genesis and tumour progressionrdquo Lancet Oncology vol 2 no 3pp 149ndash156 2001
[45] S Wang Z Liu L Wang and X Zhang ldquoNF-120581B signalingpathway inflammation and colorectal cancerrdquo Chinese Journalof Cellular andMolecular Immunology vol 6 no 5 pp 327ndash3342009
[46] V Yermilov J Rubio M Becchi M D Friesen B Pignatelliand H Ohshima ldquoFormation of 8-nitroguanine by the reactionof guanine with peroxynitrite in vitrordquo Carcinogenesis vol 16no 9 pp 2045ndash2050 1995
[47] B Halliwell ldquoOxygen and nitrogen are pro-carcinogens Dam-age to DNA by reactive oxygen chlorine and nitrogen speciesmeasurement mechanism and the effects of nutritionrdquo Muta-tion Research vol 443 no 1-2 pp 37ndash52 1999
8 Oxidative Medicine and Cellular Longevity
[48] R S Sodum and E S Fiala ldquoAnalysis of peroxynitrite reactionswith guanine xanthine and adenine nucleosides by high-pressure liquid chromatography with electrochemical detec-tion C8-nitration and -oxidationrdquo Chemical Research in Toxi-cology vol 14 no 4 pp 438ndash450 2001
[49] T Akaike S Fujii A Kato et al ldquoViral mutation acceleratedby nitric oxide production during infection in vivordquoThe FASEBJournal vol 14 no 10 pp 1447ndash1454 2000
[50] N Ma M Murata S Ohnishi R Thanan Y Hiraku and SKawanishi ldquo8-Nitroguanine a potential biomarker to evaluatethe risk of inflammation-related carcinogenesisrdquo in BiomarkerT K Kahn Ed chapter 10 pp 201ndash224 InTech Rijeka Croatia2012
[51] V Yermilov J Rubio and H Ohshima ldquoFormation of 8-nitroguanine in DNA treated with peroxynitrite in vitro and itsrapid removal from DNA by depurinationrdquo The FEBS Lettersvol 376 no 3 pp 207ndash210 1995
[52] L A Loeb and B D Preston ldquoMutagenesis by apurinicapyr-imidinic sitesrdquo Annual Review of Genetics vol 20 pp 201ndash2301986
[53] S Boiteux and M Guillet ldquoAbasic sites in DNA repair andbiological consequences in Saccharomyces cerevisiaerdquo DNARepair vol 3 no 1 pp 1ndash12 2004
[54] J E Sale A R Lehmann and R Woodgate ldquoY-family DNApolymerases and their role in tolerance of cellular DNA dam-agerdquo Nature Reviews Molecular Cell Biology vol 13 no 3 pp141ndash152 2012
[55] X Wu K Takenaka E Sonoda et al ldquoCritical roles forpolymerase 120577 in cellular tolerance to nitric oxide-induced DNAdamagerdquo Cancer Research vol 66 no 2 pp 748ndash754 2006
[56] N Suzuki M Yasui N E Geacintov V Shafirovich and SShibutani ldquoMiscoding events during DNA synthesis past thenitration-damaged base 8-nitroguaninerdquo Biochemistry vol 44no 25 pp 9238ndash9245 2005
[57] M Y Kim M Dong P C Dedon and G N Wogan ldquoEffects ofperoxynitrite dose and dose rate onDNAdamage andmutationin the supF shuttle vectorrdquo Chemical Research in Toxicology vol18 no 1 pp 76ndash86 2005
[58] IARC ldquoOpisthorchis viverrini and Clonorchis sinensisrdquo in AReview of Human CarcInogens Biological Agents vol 100B ofIARC Monographs on the Evaluation of Carcinogenic Risks toHumans pp 347ndash376 IARC Press Lyon France 2012
[59] J P EiserichM Hristova C E Cross et al ldquoFormation of nitricoxide-derived inflammatory oxidants by myeloperoxidase inneutrophilsrdquo Nature vol 391 no 6665 pp 393ndash397 1998
[60] J P Gaut J Byun H D Tran et al ldquoMyeloperoxidase producesnitrating oxidants in vivordquo Journal of Clinical Investigation vol109 no 10 pp 1311ndash1319 2002
[61] S Tanaka N Choe D R Hemenway S Zhu S Matalon andE Kagan ldquoAsbestos inhalation induces reactive nitrogen speciesand nitrotyrosine formation in the lungs and pleura of the ratrdquoJournal of Clinical Investigation vol 102 no 2 pp 445ndash4541998
[62] A Van Der Vliet J P Eiserich M K Shigenaga and C ECross ldquoReactive nitrogen species and tyrosine nitration in therespiratory tract epiphenomena or a pathobiologic mechanismof diseaserdquo American Journal of Respiratory and Critical CareMedicine vol 160 no 1 pp 1ndash9 1999
[63] A Haegens A Van Der Vliet K J Butnor et al ldquoAsbestos-induced lung inflammation and epithelial cell proliferation arealtered in myeloperoxidase-null micerdquoCancer Research vol 65no 21 pp 9670ndash9677 2005
[64] N Suzuki M Yasui N E Geacintov V Shafirovich and SShibutani ldquoMiscoding events during DNA synthesis past thenitration-damaged base 8-nitroguaninerdquo Biochemistry vol 44no 25 pp 9238ndash9245 2005
[65] S Shibutani M Takeshita and A P Grollman ldquoInsertionof specific bases during DNA synthesis past the oxidation-damaged base 8-oxodGrdquoNature vol 349 no 6308 pp 431ndash4341991
[66] J L Bos ldquoThe ras gene family and human carcinogenesisrdquoMutation Research vol 195 no 3 pp 255ndash271 1988
[67] S P Hussain L J Hofseth and C C Harris ldquoRadical causes ofcancerrdquoNature Reviews Cancer vol 3 no 4 pp 276ndash285 2003
[68] T Takahashi M M Nau I Chiba et al ldquop53 a frequent targetfor genetic abnormalities in lung cancerrdquo Science vol 246 no4929 pp 491ndash494 1989
[69] S Ohnishi H Saito N Suzuki et al ldquoNitrative and oxidativeDNA damage caused by K-ras mutation in micerdquo Biochemicaland Biophysical Research Communications vol 413 no 2 pp236ndash240 2011
[70] M Shipitsin and K Polyak ldquoThe cancer stem cell hypothesisin search of definitions markers and relevancerdquo LaboratoryInvestigation vol 88 no 5 pp 459ndash463 2008
[71] S Sell ldquoInfection stem cells and cancer signalsrdquo Current Phar-maceutical Biotechnology vol 12 no 2 pp 182ndash188 2011
[72] S Reuter S C Gupta M M Chaturvedi and B B AggarwalldquoOxidative stress inflammation and cancer how are theylinkedrdquo Free Radical Biology and Medicine vol 49 no 11 pp1603ndash1616 2010
[73] Y Jing Z Han Y Liu et al ldquoMesenchymal stem cellsin inflammation microenvironment accelerates hepatocellu-lar carcinoma metastasis by inducing epithelial-mesenchymaltransitionrdquo PLoS One vol 7 no 8 Article ID e43272 2012
[74] N J Maitland and A T Collins ldquoInflammation as the primaryaetiological agent of human prostate cancer a stem cell con-nectionrdquo Journal of Cellular Biochemistry vol 105 no 4 pp931ndash939 2008
[75] Z A Shaker M A Kaddah S B Hanallah and M I El-Khodary ldquoProduction of monoclonal antibodies against targetschistosomal antigen secreted in the urine of schistosomamansoni-infected patientsrdquo International Journal for Parasitol-ogy vol 28 no 12 pp 1893ndash1901 1998
[76] IARC ldquoSchistosoma haematobiumrdquo in A Review of HumanCarcInogens Biological Agents vol 100B of IARC Monographson the Evaluation of Carcinogenic Risks to Humans pp 371ndash384IARC Press Lyon France 2012
[77] E I Salim K Morimura A Menesi M El-Lity S Fukushimaand HWanibuchi ldquoElevated oxidative stress and DNA damageand repair levels in urinary bladder carcinomas associated withschistosomiasisrdquo International Journal of Cancer vol 123 no 3pp 601ndash608 2008
[78] A N Wamachi J S Mayadev P L Mungai et al ldquoIncreasedratio of tumor necrosis factor-120572 to interleukin-10 productionis associated with Schistosoma haematobium-induced urinary-tract morbidityrdquo Journal of Infectious Diseases vol 190 no 11pp 2020ndash2030 2004
[79] L H Looijenga H Stoop H P De Leeuw et al ldquoPOU5F1(OCT34) identifies cells with pluripotent potential in humangerm cell tumorsrdquo Cancer Research vol 63 no 9 pp 2244ndash2250 2003
[80] Y-C Chen H-S Hsu Y-W Chen et al ldquoOct-4 expressionmaintained cancer stem-like properties in lung cancer-derived
Oxidative Medicine and Cellular Longevity 9
CD133-positive cellsrdquo PLoS One vol 3 no 7 Article ID e26372008
[81] D Ponti A Costa N Zaffaroni et al ldquoIsolation and in vitropropagation of tumorigenic breast cancer cells with stempro-genitor cell propertiesrdquo Cancer Research vol 65 no 13 pp5506ndash5511 2005
[82] Y Matsumura and D Tarin ldquoSignificance of CD44 geneproducts for cancer diagnosis and disease evaluationrdquo Lancetvol 340 no 8827 pp 1053ndash1058 1992
[83] S Saito H Okabe M Watanabe et al ldquoCD44v6 expressionis related to mesenchymal phenotype and poor prognosis inpatients with colorectal cancerrdquo Oncology Reports vol 29 no4 pp 1570ndash1578 2013
[84] E M Peek D R Li H Zhang et al ldquoStromal modulation ofbladder cancer-initiating cells in a subcutaneous tumor modelrdquoAmerican Journal of Cancer Research vol 2 no 6 pp 745ndash7512012
[85] J Kuncova M Urban and V Mandys ldquoExpression of CD44sand CD44v6 in transitional cell carcinomas of the urinarybladder comparison with tumour grade proliferative activityand p53 immunoreactivity of tumour cellsrdquoAPMIS vol 115 no11 pp 1194ndash1205 2007
[86] M Sugiyama A Woodman T Sugino et al ldquoNon-invasivedetection of bladder cancer by identification of abnormal CD44proteins in exfoliated cancer cells in urinerdquo Journal of ClinicalMolecular Pathology vol 48 no 3 pp M142ndashM147 1995
[87] Y M Yang and J W Chang ldquoBladder cancer initiating cells(BCICs) are among EMAminusCD44v6+ subset novel methods forisolating undetermined cancer stem (initiating) cellsrdquo CancerInvestigation vol 26 no 7 pp 725ndash733 2008
[88] R Thanan S Oikawa P Yongvanit et al ldquoInflammation-induced protein carbonylation contributes to poor prognosisfor cholangiocarcinomardquo Free Radical Biology and Medicinevol 52 no 8 pp 1465ndash1472 2012
2 Oxidative Medicine and Cellular Longevity
Table 1 Possible markers for cancer stem cells in inflammation-related cancer
Etiologic agentpathologic condition Associated cancer Detection of
8-nitroguanine
Possible markers for cancer stemcells related to each cause[references]
Parasites SH Bladder cancer Patients [10 11] Oct34 (patients with SH) [10]CD44v6 (patients without SH) [11]
OV Cholangiocarcinoma Hamsters [12ndash15] mdashPatients [16 17] CD133 Oct34 [17]
SH Schistosoma haematobium OV Opisthorchis viverrini HCV hepatitis C virus HBV hepatitis B virus HPV human papillomavirus EBV Epstein-Barrvirus HP Helicobacter pylori IBD inflammatory bowel diseases LP lichen planus BE Barrettrsquos esophagus DN data not shown
adenine ismisincorporated opposite 8-oxodG leading toGCto TA transversions [9]
Nitric oxide (NO) is synthesized by NO synthases Thereare three isoforms neuronal NO synthase (nNOS alsoknown as NOS1) inducible NO synthase (iNOS or NOS2)and endothelial NO synthase (eNOS or NOS3) [43 44]iNOS is activated to drastically generate NO in inflammatoryand epithelial cells under inflammatory conditions whileeNOS and nNOS are constitutively expressed and producerelatively small amounts of NO iNOS can be also upregulatedby transcription factors such as NF-120581B HIF1-120572 STAT andTNF-120572 NF-120581B plays a central role in inflammation throughits ability to induce transcription of proinflammatory genesincluding iNOS and functions as a tumor promoter ininflammation-associated cancer [45]
ExcessNOproduction plays a crucial role in an enormousvariety of pathological processes including cancer [43]NO reacts with superoxide (O
2
∙minus) to form peroxynitrite(ONOOminus) a highly reactive species causing 8-oxodG and 8-nitroguanine [46 47] The reaction of guanine with ONOOminusforms 8-nitroguanine as the major compound [46] while
adenine nitration is minor compared to its C8-oxidation[48] Akaike et al have demonstrated that 8-nitroguanine isformed via NO production associated with inflammation inmice with viral pneumonia [49] 8-Nitroguanine is consid-ered to be not only a marker of inflammation but also apotential mutagenic DNA lesion leading to carcinogenesis[50] 8-Nitroguanine formed in DNA is chemically unstableand thus can be spontaneously released resulting in theformation of an apurinic site [51] The apurinic site can forma pair with adenine during DNA synthesis leading to GC toTA transversions [52] However the discovery of translesionDNA polymerases and their role in the mutagenesis in livingcells made this paradigm rather obsolete [53 54] AP sitesare indeed mutagenic but the A-rule does not really describeits mutagenic potential Cells deficient in Rev1 and Rev3subunits of DNA polymerase 120577 were hypersensitive to nitra-tive stress and translesion DNA synthesis past apurinic sitesmediated by this polymerase might contribute to extensivepoint mutations [55] It has been reported that adenine ispreferentially incorporated opposite 8-nitroguanine duringDNA synthesis catalyzed by polymerase 120578 and 120581ΔC in
Oxidative Medicine and Cellular Longevity 3
a cell-free system suggesting that GC to TA transversionscan occur [56] In the ONOOminus-treated supF shuttle vectorwhich was replicated in host Escherichia coli cells the major-ity of mutations occurred at GC base pairs predominantlyinvolvingGC toTA transversions [57]Thus 8-nitroguanineis a potentially mutagenic DNA lesion that can participate ininitiation and promotion in infection-related carcinogenesis
Wehave investigated the formation of 8-nitroguanine and8-oxodG in various clinical specimens and animal modelsin relation to inflammation-related carcinogenesis as sum-marized in Table 1 It is noteworthy that DNA damage wasspecifically induced at sites of carcinogenesis under chronicinfection and various inflammatory conditions as reviewedpreviously [2 3] It has been estimated that 11 infectiousagents are carcinogenic to humans (Group 1) by IARC par-asites (Schistosoma haematobium (SH) Opisthorchis viver-rini (OV) and Clonorchis sinensis (CS)) viruses (hepatitisB and C virus (HBV and HCV) human papillomavirus(HPV) Epstein-Barr virus (EBV) humanT-cell lymphotrop-ic virus (HTLV-1) Kaposirsquos sarcoma herpesvirus (KSHV)and human immunodeficiency virus-1 (HIV-1)) and bac-terium Helicobacter pylori (HP) [4 58] We demonstratedthat 8-nitroguaninewas strongly formed via iNOS expressionat related cancer sites of SH OV HBV HCV HPV EBVand HP [2 3 10 11] The IARC classification of CS hasbeen recently updated from 2A to 1 so we have not yetcollected enough data for 8-nitroguanine The mechanismof carcinogenesis by HTLV-1 KSHV or HIV-1 seems notto be associative to inflammation We could not observe 8-nitroguanine in leukaemia samples from patients infectedwith HTLV-1 (data not shown) 8-Nitroguanine was alsoformed in tissues from patients with inflammatory diseasessuch as inflammatory bowel diseases (IBD) Lichen planus(LP) and Barrettrsquos esophagus (BE) [3 38] Recently wehave reported that the formation of 8-nitroguanine and8-oxodG increased significantly in the order of Barrettrsquosesophageal adenocarcinoma gt Barrettrsquos esophagus gt normaltissues Treatment of BEpatientswith proton pump inhibitors(PPIs) which is expected to reduce the risk of Barrettrsquosesophageal adenocarcinoma suppressed these DNA lesionsprobably via activation of an antioxidant enzyme Mn-SOD[38] Regarding inflammation-related carcinogenesis withoutinfection we describe the formation of 8-nitroguanine inlung tissues of mice intratracheally administered asbestos[42] although the precise mechanism of nitrative DNAdamage remains to be clarified Nitrative stress is involved inthe asbestos-derived inflammatory response via myeloperox-idase [59ndash62] that plays a significant role in asbestos-inducedcarcinogenesis [63] Interestingly immunoreactivities of 8-nitroguanine iNOS andNF-120581B significantly increased in theorder of carcinogenic potential crocidolite (blue asbestos) gtchrysotile (white asbestos) gt control [42]
On the basis of our studies various pathogenic factorsinduce inflammatory responses and the production of ROSand RNS from inflammatory and epithelial cells via iNOSexpression which is regulated by transcriptional factorsincluding NF-120581B STAT and HIF-1120572 [2 3] Oxidative andnitrative stresses cause DNA damage contributing to theaccumulation of genetic alterations in tissues throughout
the carcinogenic process Particularly 8-nitroguanine for-mation may participate in inflammation-related carcinogen-esis as a common mechanism Therefore 8-nitroguaninecould be used as a potential biomarker of inflammation-related carcinogenesis Importantly experimental evidencehas suggested that 8-nitroguanine can lead to mutationspreferentially GC to TA transversions [46 64] in additionto 8-oxodG [9 65] Indeed GC to TA transversions havebeen observed in vivo in the ras gene [66] and the p53tumor suppressor gene in lung and liver cancer [67 68]We also revealed that 8-nitroguanine and 8-oxodG wereapparently formed in adenocarcinoma caused by mutatedK-ras by using conditional transgenic mice with K-rasV11988611989712[69] 8-Nitroguanine was colocalized with iNOS NF-120581BIKK MAPK MEK and mutated K-ras suggesting thatoncogenic K-ras causes additional DNAdamage via signalingpathways involving these molecules It is noteworthy thatK-ras mutation mediates not only cell overproliferation butalso the accumulation of mutagenic DNA lesions leadingto carcinogenesis These findings imply that DNA damagemediated by ROS and RNS may participate in carcinogenesisvia activation of protooncogenes and inactivation of tumorsuppressor genes
2 Cancer Stem Cell Markers inInflammation-Related Carcinogenesis
The cancer stem cell concept is widely accepted as importantfor overcoming cancer Several studies have revealed that can-cer cells show accumulation of mutations genetic instabilityand epigenetic change suggesting that cancer is also a diseaseof genes [70]Themost important question is how to generatecancer stem cells Recently many studies have reported onthe expressions of stemness cell markers in various kindsof cancer Table 1 summarizes possible markers of cancerstem cells especially related to each inflammatory causativeagent We reported that 8-nitroguanine was strongly formedat all of these cancer sites from animals and patients withinfectious agents inflammatory diseases and exposure toasbestos Importantly we also detected colocalization of8-nitroguanine and stemness marker in infection-relatedcarcinogenesis as mentioned in the next section On thebasis of our recent studies it is considered that chronicinflammation can increase mutagenic DNA lesions throughROSRNS generation and can promote proliferation via stemcells activation for tissue regeneration This idea is alsosupported by other papers about the association of cancerstem cells with infection and inflammation [71ndash74]
3 DNA Damage and MutantStem Cells Induced bySchistosoma haematobium Infection
Chronic infection with SH is associated with urinary bladdercancer [76] Contact with contaminated freshwater is themajor risk factor for infection SH-associated bladder canceris a common malignancy especially in the Middle East andAfrica It is believed that the parasitersquos eggs in the host
4 Oxidative Medicine and Cellular Longevity
8-Nitroguanine Oct34 Merged
Nor
mal
Cysti
tis (S
H+)
Canc
er (S
H+
)Ca
ncer
(SHminus
)
Figure 1The formation of 8-nitroguanine (red) and the expression of Oct34 (green) were assessed by double immunofluorescence staining[10] In the merged image co-localization of 8-nitroguanine and Oct34 is indicated in yellow Original magnification in all pictures is 200x(SH Schistosoma haematobium) Formalin-fixed and paraffin-embedded biopsy and surgical specimens were obtained from normal subjectsand patients with SH-induced cystitis and bladder cancer Normal tissues and urinary bladder cancer tissues without SH infection wereobtained from a commercial urinary bladder tissue array (Biomaxus USA) Normal tissues with cystitis were excluded SH-egg antigens insera were detected by Sandwich ELISA assay [75] This study was performed in accordance with the Ethical Guidelines for EpidemiologicalResearch enacted by the Japanese government Deparaffinized and antigen-retrieved sections were incubated first with 5 skim milk andthen with a rabbit polyclonal anti-8-nitroguanine antibody (2 120583gmL prepared as described previously [11]) and mouse monoclonal anti-Oct34 antibody (2120583gmL Santa Cruz Biotechnology CA USA) overnight at room temperature The sections were then incubated for 3 hwith Alexa 594-labeled goat antibody against rabbit IgG and Alexa 488-labeled goat antibody against mouse IgG (each 1 400 MolecularProbes Eugene OR USA)
bladder result in irritation eventual fibrosis and chronic cys-titis leading to carcinogenesis To investigate whether oxida-tive and nitrative DNA damage participate in inflammation-related carcinogenesis we performed immunohistochemicalanalysis using bladder tissues obtained from cystitis and blad-der cancer patients infected with SH We demonstrated forthe first time that 8-nitroguanine is formed in the tumors ofbladder cancer patients with SH infection [10]The formationof 8-nitroguanine and 8-oxodG was significantly higher inbladder cancer and cystitis tissues than in normal tissuesOxidative DNA damage and SH infection were stronglycorrelated [10 77] iNOS expression was co-localized withNF-120581B in 8-nitroguanine-positive tumor cells from bladdercancer patients NF-120581B can be activated by TNF-120572 a majormediator of inflammation which has been reported toincrease in peripheral bloodmononuclear cells stimulated bySH egg antigen [78] It is reasonable to conclude that both8-nitroguanine and 8-oxodG are formed by iNOS-mediatedNO overproduction via NF-120581B activation under SH-causedchronic inflammation
A stemness marker Oct34 is generally expressed in plu-ripotent embryonic stem and germ cells [79] Expression
of Oct34 is reportedly necessary for maintaining the self-renewing cancer stem-like and chemoradioresistant proper-ties of tumorigenic stem-like cell populations [80 81] and isthus considered to play roles in the carcinogenesis processAnother stemness marker CD44 has been identified asa cell surface marker associated with cancer stem cells inseveral types of tumors [82 83] including urinary bladdercancer [84] Expression of CD44v6 a splicing variant ofCD44 is correlated with proliferation of poorly differentiatedurothelial cells and the characteristic phenotype of tumor-initiating bladder cancer stem cells [85ndash87] Our previousreports show that different risk factors induce differentlevels of expression of stemness markers in urinary bladdercarcinoma SH-induced urinary bladder cancer correlateswith the expression of Oct34 [10] while urinary bladdercancer without the infection correlates with the expressionof CD44v6 [11] Moreover 8-nitroguanine was formed inOct34-positive stem cells in SH-associated cystitis and can-cer tissues [10] as shown in Figure 1 Inflammation by SHinfection may increase the number of mutant stem cellsin which iNOS-dependent DNA damage occurs via NF-120581Bactivation leading to tumor development
Figure 2 Postulated mechanism for generating cancer stem cells by inflammation
4 DNA Damage and Mutant Stem CellsInduced by Opisthorchis viverrini Infection
Chronic infection with the liver fluke OV is associatedwith cholangiocarcinomas [58] Infection with this para-site is repeatedly caused by eating raw fish containing theinfective stage of the fluke We have demonstrated that 8-nitroguanine is formed in relation to inflammation-relatedcarcinogenesis using an animal model [12ndash15] 8-OxodGand 8-nitroguanine were formed in inflammatory cells andepithelium of bile ducts and their formation increased in amanner dependent on infection timesThe anthelmintic drugpraziquantel dramatically diminished these DNA lesions andiNOS expression in OV-infected hamsters Thus repeatedOV-infection can induce the iNOS expression in bile ductsand subsequently cause nitrative and oxidative damage tonucleic acids which may participate in cholangiocarcinoma
In our study with patients the formation of 8-oxodGand 8-nitroguanine occurred to a much greater extent incancerous tissue than in noncancerous tissue in intrahepaticcholangiocarcinoma patients indicating that these DNAlesions contribute to tumor progression [16] Our proteomicstudy showed that carbonylation of serotransferrin and heatshock protein 70 kDa protein 1 (HSP701) is significantlyassociated with poor prognoses [88] Carbonylation of pro-tein is an irreversible modification induced by oxidativestress We have proposed that carbonylations of serotrans-ferrin and HSP701 may induce oxidative stress by iron-accumulation and dysfunction of antioxidative propertyleading to increased oxidative DNA damage and progressionof cholangiocarcinoma
Recently we observed high expression and co-locali-zation of hepatocyte marker and cholangiocyte marker inOV-associated cholangiocarcinoma patients suggesting the
6 Oxidative Medicine and Cellular Longevity
involvement of stem cells in cholangiocarcinoma develop-ment [17] Cholangiocarcinoma tissues with positive stem-ness markers (CD133 or Oct34) showed significantly lowerexpression of antioxidant enzyme Mn-SOD and significantlyhigher levels of 8-oxodG 8-nitroguanine and DNA damageresponse protein 120574-H2AX Moreover CD133- and Oct34-positive cholangiocarcinoma patients had significant associa-tionswith tumor histology types tumor stage and poor prog-noses These findings suggest that CD133 and Oct34 in cho-langiocarcinoma are highly associated with formation ofDNA lesions whichmay be involved in genetic instability andlead to tumor development with aggressive clinical featuresIn our study proliferating cell nuclear antigen (PCNA)accumulated in the epithelium of bile ducts of hamsters afterrepeated OV infection supporting the hypothesis that cellproliferation is promoted by inflammation-mediated DNAdamage [14] Inflammation by OV infection may increasethe number of mutant stem cell in which oxidative stressessuch as carbonylation of proteins and oxidativeDNAdamageand cell proliferation are promoted leading to progression ofcholangiocarcinoma
5 Conclusions
Nitrative and oxidative DNA lesions with mutagenic proper-ties are formed in various types of inflammation-related can-cer tissuesWehave proposed amechanism for the generationof cancer stem cells by inflammation in Figure 2 Chronicinflammation by infectious agents inflammatory diseasesand other factors causes various types of damage to nucleicacids proteins tissue and so on via ROSRNS generationTissue injury under chronic inflammation may activate pro-genitorstem cells for regeneration In these cells ROSRNSfrom inflammation can cause multiple mutations whichmaygenerate mutant stem cells and cancer stem cells leadingto carcinogenesis Indeed 8-nitroguanine was formed instemness marker-positive cells in parasite-associated cancertissues The mechanism for generation of cancer stem cellswill be explained by our ongoing studies on the formation of8-nitroguanine in stem-like cells of target tissues associatedwith other inflammation-related cancers
Conflict of Interests
The authors declare that they have no conflict of interests
Acknowledgment
This work was supported by a grant-in-aid from theMinistryof Education Culture Sports Science and Technology ofJapan
References
[1] L M Coussens and Z Werb ldquoInflammation and cancerrdquoNature vol 420 no 6917 pp 860ndash867 2002
[2] S Kawanishi and Y Hiraku ldquoOxidative and nitrative DNAdamage as biomarker for carcinogenesis with special reference
to inflammationrdquo Antioxidants and Redox Signaling vol 8 no5-6 pp 1047ndash1058 2006
[3] M Murata R Thanan N Ma and S Kawanishi ldquoRole ofnitrative and oxidative DNA damage in inflammation-relatedcarcinogenesisrdquo Journal of Biomedicine and Biotechnology vol2012 Article ID 623019 11 pages 2012
[4] IARC ldquoChronic infectionsrdquo in World Cancer Report B WStewart and P Kleihues Eds pp 128ndash135 IARC Press LyonFrance 2008
[5] S P Hussain and C C Harris ldquoInflammation and canceran ancient link with novel potentialsrdquo International Journal ofCancer vol 121 no 11 pp 2373ndash2380 2007
[6] A J Schetter N H Heegaard and C C Harris ldquoInflammationand cancer interweaving microRNA free radical cytokine andp53 pathwaysrdquo Carcinogenesis vol 31 no 1 Article ID bgp272pp 37ndash49 2010
[7] H Ohshima M Tatemichi and T Sawa ldquoChemical basis ofinflammation-induced carcinogenesisrdquo Archives of Biochem-istry and Biophysics vol 417 no 1 pp 3ndash11 2003
[8] S Kawanishi Y Hiraku and S Oikawa ldquoMechanism ofguanine-specific DNA damage by oxidative stress and its rolein carcinogenesis and agingrdquoMutation Research vol 488 no 1pp 65ndash76 2001
[9] S D Bruner D P G Norman and G L Verdine ldquoStructuralbasis for recognition and repair of the endogenous mutagen 8-oxoguanine in DNArdquo Nature vol 403 no 6772 pp 859ndash8662000
[10] N Ma R Thanan H Kobayashi et al ldquoNitrative DNA damageand Oct34 expression in urinary bladder cancer with Schis-tosoma haematobium infectionrdquo Biochemical and BiophysicalResearch Communications vol 414 no 2 pp 344ndash349 2011
[11] R Thanan M Murata N Ma et al ldquoNuclear localization ofCOX-2 in relation to the expression of stemness markers inurinary bladder cancerrdquo Mediators of Inflammation vol 2012Article ID 165879 8 pages 2012
[12] S Pinlaor Y Hiraku P Yongvanit et al ldquoiNOS-dependentDNA damage via NF-120581B expression in hamsters infected withOpisthorchis viverrini and its suppression by the antihelminthicdrug praziquantelrdquo International Journal of Cancer vol 119 no5 pp 1067ndash1072 2006
[13] S Pinlaor Y Hiraku NMa et al ldquoMechanism of NO-mediatedoxidative and nitrative DNA damage in hamsters infectedwithOpisthorchis viverrini a model of inflammation-mediatedcarcinogenesisrdquo Nitric Oxide vol 11 no 2 pp 175ndash183 2004
[14] S Pinlaor N Ma Y Hiraku et al ldquoRepeated infection withOpisthorchis viverrini induces accumulation of 8-nitroguanineand 8-oxo-78-dihydro-21015840-deoxyguanine in the bile duct ofhamsters via inducible nitric oxide synthaserdquo Carcinogenesisvol 25 no 8 pp 1535ndash1542 2004
[15] S Pinlaor P Yongvanit YHiraku et al ldquo8-Nitroguanine forma-tion in the liver of hamsters infectedwithOpisthorchis viverrinirdquoBiochemical and Biophysical Research Communications vol 309no 3 pp 567ndash571 2003
[16] S Pinlaor B Sripa N Ma et al ldquoNitrative and oxidative DNAdamage in intrahepatic cholangiocarcinoma patients in relationto tumor invasionrdquo World Journal of Gastroenterology vol 11no 30 pp 4644ndash4649 2005
[17] R Thanan C Pairojkul S Pinlaor et al ldquoInflammation-related DNA damage and expression of CD133 and Oct34 incholangiocarcinoma patients with poor prognosisrdquo Free RadicalBiology amp Medicine 2013
Oxidative Medicine and Cellular Longevity 7
[18] S Horiike S Kawanishi M Kaito et al ldquoAccumulation of 8-nitroguanine in the liver of patients with chronic hepatitis CrdquoJournal of Hepatology vol 43 no 3 pp 403ndash410 2005
[19] N Ali H Allam R May et al ldquoHepatitis C virus-inducedcancer stem cell-like signatures in cell culture and murinetumor xenograftsrdquo Journal of Virology vol 85 no 23 pp 12292ndash12303 2011
[20] K Machida H Tsukamoto H Mkrtchyan et al ldquoToll-likereceptor 4 mediates synergism between alcohol and HCVin hepatic oncogenesis involving stem cell marker NanogrdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 106 no 5 pp 1548ndash1553 2009
[21] Y Hiraku T Tabata N Ma M Murata X Ding and SKawanishi ldquoNitrative and oxidative DNA damage in cervicalintraepithelial neoplasia associatedwith humanpapilloma virusinfectionrdquo Cancer Science vol 98 no 7 pp 964ndash972 2007
[22] S-K Kim H-S Shim K-G Lee H-J An K-R Lee andN-H Cho ldquoGlassy cell carcinoma predominantly commits toa squamous lineage and is strongly associated with high-risktype human papillomavirus infectionrdquo International Journal ofGynecological Pathology vol 28 no 4 pp 389ndash395 2009
[23] S Regauer and O Reich ldquoCK17 and p16 expression pat-terns distinguish (atypical) immature squamous metaplasiafrom high-grade cervical intraepithelial neoplasia (CIN III)rdquoHistopathology vol 50 no 5 pp 629ndash635 2007
[24] W-K Liu Y-L Chu F Zhang et al ldquoThe relationship betweenHPV16 and expression of CD44v6 nm23H1 in esophagealsquamous cell carcinomardquo Archives of Virology vol 150 no 5pp 991ndash1001 2005
[25] D Liu P Zhou L Zhang et al ldquoHDAC1DNMT3A-containingcomplex is associated with suppression of Oct4 in cervicalcancer cellsrdquo Biochemistry vol 77 no 8 pp 934ndash940 2012
[26] N Ma M Kawanishi Y Hiraku et al ldquoReactive nitrogenspecies-dependent DNA damage in EBV-associated nasopha-ryngeal carcinoma the relation to STAT3 activation and EGFRexpressionrdquo International Journal of Cancer vol 122 no 11 pp2517ndash2525 2008
[27] Q-L Kong L-J Hu J-Y Cao et al ldquoEpstein-barr virus-encoded LMP2A induces an epithelialmdashmesenchymal transi-tion and increases the number of side population stem-likecancer cells in nasopharyngeal carcinomardquo PLoS Pathogens vol6 no 6 Article ID e1000940 2010
[28] A Dutton C B Woodman M B Chukwuma et al ldquoBmi-1 isinduced by the Epstein-Barr virus oncogene LMP1 and regulatesthe expression of viral target genes inHodgkin lymphoma cellsrdquoBlood vol 109 no 6 pp 2597ndash2603 2007
[29] N Ma Y Adachi Y Hiraku et al ldquoAccumulation of 8-nitroguanine in human gastric epithelium induced by Heli-cobacter pylori infectionrdquo Biochemical and Biophysical ResearchCommunications vol 319 no 2 pp 506ndash510 2004
[30] M Katsurahara Y Kobayashi M Iwasa et al ldquoReactivenitrogen species mediate DNA damage in helicobacter pylori-infected gastric mucosardquo Helicobacter vol 14 no 6 pp 552ndash558 2009
[31] Y Fujii K Yoshihashi H Suzuki et al ldquoCDX1 confers intestinalphenotype on gastric epithelial cells via induction of stemness-associated reprogramming factors SALL4 and KLF5rdquo Proceed-ings of the National Academy of Sciences of USA vol 109 no 50pp 20584ndash10589 2012
[32] J M Noto T Khizanishvili R Chaturvedi et al ldquoHelicobacterpylori promotes the expression of Kruppel-like factor 5
a mediator of carcinogenesis in vitro and in vivordquo PLoS Onevol 8 no 1 Article ID e54344 2013
[33] T Uehara D Ma Y Yao et al ldquoH pylori infection is associatedwith DNA damage of Lgr5-positive epithelial stem cells in thestomach of patients with gastric cancerrdquo Digestive Diseases andSciences vol 58 no 1 pp 140ndash149 2013
[34] X Ding Y Hiraku N Ma et al ldquoInducible nitric oxidesynthase-dependent DNA damage in mouse model of inflam-matory bowel diseaserdquoCancer Science vol 96 no 3 pp 157ndash1632005
[35] P Chaiyarit N Ma Y Hiraku et al ldquoNitrative and oxidativeDNA damage in oral lichen planus in relation to human oralcarcinogenesisrdquoCancer Science vol 96 no 9 pp 553ndash559 2005
[36] L Ma H Wang H Yao L Zhu W Liu and Z Zhou ldquoBmi1expression in oral lichen planus and the risk of progression tooral squamous cell carcinomardquo Annals of Diagnostic Pathologyvol 17 no 4 pp 327ndash330 2013
[37] A Bose M T Teh I L Hutchison H Wan I M Leigh andA Waseem ldquoTwo mechanisms regulate keratin K15 expressionin keratinocytes role of PKCAP-1 and FOXM1 mediatedsignallingrdquo PLoS One vol 7 no 6 Article ID e38599 2012
[38] RThanan NMa K Iijima et al ldquoProton pump inhibitors sup-press iNOS-dependent DNA damage in Barrettrsquos esophagus byincreasing Mn-SOD expressionrdquo Biochemical and BiophysicalResearch Communications vol 421 no 2 pp 280ndash285 2012
[39] J Mendelson S Song Y Li et al ldquoDysfunctional transform-ing growth factor-120573 signaling with constitutively active notchsignaling in Barrettrsquos esophageal adenocarcinomardquo Cancer vol117 no 16 pp 3691ndash3702 2011
[40] J Ahmad K Arthur P Maxwell et al ldquoRe grotenhuis et alBarrettrsquos oesophageal adenocarcinoma encompasses tumour-initiating cells that do not express common cancer stem cellmarkers J Pathol 2010 221 379ndash389rdquo Journal of Pathology vol224 no 1 pp 143ndash145 2011
[41] Y V Bobryshev A K Freeman N K Botelho D Tran AJ M Levert-Mignon and R V N Lord ldquoExpression of theputative stem cell marker Musashi-1 in Barrettrsquos esophagus andesophageal adenocarcinomardquoDiseases of the Esophagus vol 23no 7 pp 580ndash589 2010
[42] Y Hiraku S Kawanishi T Ichinose and M Murata ldquoThe roleof iNOS-mediated DNA damage in infection- and asbestos-induced carcinogenesisrdquo Annals of the New York Academy ofSciences vol 1203 pp 15ndash22 2010
[43] D Fukumura S Kashiwagi and R K Jain ldquoThe role of nitricoxide in tumour progressionrdquoNature Reviews Cancer vol 6 no7 pp 521ndash534 2006
[44] P K Lala and C Chakraborty ldquoRole of nitric oxide in carcino-genesis and tumour progressionrdquo Lancet Oncology vol 2 no 3pp 149ndash156 2001
[45] S Wang Z Liu L Wang and X Zhang ldquoNF-120581B signalingpathway inflammation and colorectal cancerrdquo Chinese Journalof Cellular andMolecular Immunology vol 6 no 5 pp 327ndash3342009
[46] V Yermilov J Rubio M Becchi M D Friesen B Pignatelliand H Ohshima ldquoFormation of 8-nitroguanine by the reactionof guanine with peroxynitrite in vitrordquo Carcinogenesis vol 16no 9 pp 2045ndash2050 1995
[47] B Halliwell ldquoOxygen and nitrogen are pro-carcinogens Dam-age to DNA by reactive oxygen chlorine and nitrogen speciesmeasurement mechanism and the effects of nutritionrdquo Muta-tion Research vol 443 no 1-2 pp 37ndash52 1999
8 Oxidative Medicine and Cellular Longevity
[48] R S Sodum and E S Fiala ldquoAnalysis of peroxynitrite reactionswith guanine xanthine and adenine nucleosides by high-pressure liquid chromatography with electrochemical detec-tion C8-nitration and -oxidationrdquo Chemical Research in Toxi-cology vol 14 no 4 pp 438ndash450 2001
[49] T Akaike S Fujii A Kato et al ldquoViral mutation acceleratedby nitric oxide production during infection in vivordquoThe FASEBJournal vol 14 no 10 pp 1447ndash1454 2000
[50] N Ma M Murata S Ohnishi R Thanan Y Hiraku and SKawanishi ldquo8-Nitroguanine a potential biomarker to evaluatethe risk of inflammation-related carcinogenesisrdquo in BiomarkerT K Kahn Ed chapter 10 pp 201ndash224 InTech Rijeka Croatia2012
[51] V Yermilov J Rubio and H Ohshima ldquoFormation of 8-nitroguanine in DNA treated with peroxynitrite in vitro and itsrapid removal from DNA by depurinationrdquo The FEBS Lettersvol 376 no 3 pp 207ndash210 1995
[52] L A Loeb and B D Preston ldquoMutagenesis by apurinicapyr-imidinic sitesrdquo Annual Review of Genetics vol 20 pp 201ndash2301986
[53] S Boiteux and M Guillet ldquoAbasic sites in DNA repair andbiological consequences in Saccharomyces cerevisiaerdquo DNARepair vol 3 no 1 pp 1ndash12 2004
[54] J E Sale A R Lehmann and R Woodgate ldquoY-family DNApolymerases and their role in tolerance of cellular DNA dam-agerdquo Nature Reviews Molecular Cell Biology vol 13 no 3 pp141ndash152 2012
[55] X Wu K Takenaka E Sonoda et al ldquoCritical roles forpolymerase 120577 in cellular tolerance to nitric oxide-induced DNAdamagerdquo Cancer Research vol 66 no 2 pp 748ndash754 2006
[56] N Suzuki M Yasui N E Geacintov V Shafirovich and SShibutani ldquoMiscoding events during DNA synthesis past thenitration-damaged base 8-nitroguaninerdquo Biochemistry vol 44no 25 pp 9238ndash9245 2005
[57] M Y Kim M Dong P C Dedon and G N Wogan ldquoEffects ofperoxynitrite dose and dose rate onDNAdamage andmutationin the supF shuttle vectorrdquo Chemical Research in Toxicology vol18 no 1 pp 76ndash86 2005
[58] IARC ldquoOpisthorchis viverrini and Clonorchis sinensisrdquo in AReview of Human CarcInogens Biological Agents vol 100B ofIARC Monographs on the Evaluation of Carcinogenic Risks toHumans pp 347ndash376 IARC Press Lyon France 2012
[59] J P EiserichM Hristova C E Cross et al ldquoFormation of nitricoxide-derived inflammatory oxidants by myeloperoxidase inneutrophilsrdquo Nature vol 391 no 6665 pp 393ndash397 1998
[60] J P Gaut J Byun H D Tran et al ldquoMyeloperoxidase producesnitrating oxidants in vivordquo Journal of Clinical Investigation vol109 no 10 pp 1311ndash1319 2002
[61] S Tanaka N Choe D R Hemenway S Zhu S Matalon andE Kagan ldquoAsbestos inhalation induces reactive nitrogen speciesand nitrotyrosine formation in the lungs and pleura of the ratrdquoJournal of Clinical Investigation vol 102 no 2 pp 445ndash4541998
[62] A Van Der Vliet J P Eiserich M K Shigenaga and C ECross ldquoReactive nitrogen species and tyrosine nitration in therespiratory tract epiphenomena or a pathobiologic mechanismof diseaserdquo American Journal of Respiratory and Critical CareMedicine vol 160 no 1 pp 1ndash9 1999
[63] A Haegens A Van Der Vliet K J Butnor et al ldquoAsbestos-induced lung inflammation and epithelial cell proliferation arealtered in myeloperoxidase-null micerdquoCancer Research vol 65no 21 pp 9670ndash9677 2005
[64] N Suzuki M Yasui N E Geacintov V Shafirovich and SShibutani ldquoMiscoding events during DNA synthesis past thenitration-damaged base 8-nitroguaninerdquo Biochemistry vol 44no 25 pp 9238ndash9245 2005
[65] S Shibutani M Takeshita and A P Grollman ldquoInsertionof specific bases during DNA synthesis past the oxidation-damaged base 8-oxodGrdquoNature vol 349 no 6308 pp 431ndash4341991
[66] J L Bos ldquoThe ras gene family and human carcinogenesisrdquoMutation Research vol 195 no 3 pp 255ndash271 1988
[67] S P Hussain L J Hofseth and C C Harris ldquoRadical causes ofcancerrdquoNature Reviews Cancer vol 3 no 4 pp 276ndash285 2003
[68] T Takahashi M M Nau I Chiba et al ldquop53 a frequent targetfor genetic abnormalities in lung cancerrdquo Science vol 246 no4929 pp 491ndash494 1989
[69] S Ohnishi H Saito N Suzuki et al ldquoNitrative and oxidativeDNA damage caused by K-ras mutation in micerdquo Biochemicaland Biophysical Research Communications vol 413 no 2 pp236ndash240 2011
[70] M Shipitsin and K Polyak ldquoThe cancer stem cell hypothesisin search of definitions markers and relevancerdquo LaboratoryInvestigation vol 88 no 5 pp 459ndash463 2008
[71] S Sell ldquoInfection stem cells and cancer signalsrdquo Current Phar-maceutical Biotechnology vol 12 no 2 pp 182ndash188 2011
[72] S Reuter S C Gupta M M Chaturvedi and B B AggarwalldquoOxidative stress inflammation and cancer how are theylinkedrdquo Free Radical Biology and Medicine vol 49 no 11 pp1603ndash1616 2010
[73] Y Jing Z Han Y Liu et al ldquoMesenchymal stem cellsin inflammation microenvironment accelerates hepatocellu-lar carcinoma metastasis by inducing epithelial-mesenchymaltransitionrdquo PLoS One vol 7 no 8 Article ID e43272 2012
[74] N J Maitland and A T Collins ldquoInflammation as the primaryaetiological agent of human prostate cancer a stem cell con-nectionrdquo Journal of Cellular Biochemistry vol 105 no 4 pp931ndash939 2008
[75] Z A Shaker M A Kaddah S B Hanallah and M I El-Khodary ldquoProduction of monoclonal antibodies against targetschistosomal antigen secreted in the urine of schistosomamansoni-infected patientsrdquo International Journal for Parasitol-ogy vol 28 no 12 pp 1893ndash1901 1998
[76] IARC ldquoSchistosoma haematobiumrdquo in A Review of HumanCarcInogens Biological Agents vol 100B of IARC Monographson the Evaluation of Carcinogenic Risks to Humans pp 371ndash384IARC Press Lyon France 2012
[77] E I Salim K Morimura A Menesi M El-Lity S Fukushimaand HWanibuchi ldquoElevated oxidative stress and DNA damageand repair levels in urinary bladder carcinomas associated withschistosomiasisrdquo International Journal of Cancer vol 123 no 3pp 601ndash608 2008
[78] A N Wamachi J S Mayadev P L Mungai et al ldquoIncreasedratio of tumor necrosis factor-120572 to interleukin-10 productionis associated with Schistosoma haematobium-induced urinary-tract morbidityrdquo Journal of Infectious Diseases vol 190 no 11pp 2020ndash2030 2004
[79] L H Looijenga H Stoop H P De Leeuw et al ldquoPOU5F1(OCT34) identifies cells with pluripotent potential in humangerm cell tumorsrdquo Cancer Research vol 63 no 9 pp 2244ndash2250 2003
[80] Y-C Chen H-S Hsu Y-W Chen et al ldquoOct-4 expressionmaintained cancer stem-like properties in lung cancer-derived
Oxidative Medicine and Cellular Longevity 9
CD133-positive cellsrdquo PLoS One vol 3 no 7 Article ID e26372008
[81] D Ponti A Costa N Zaffaroni et al ldquoIsolation and in vitropropagation of tumorigenic breast cancer cells with stempro-genitor cell propertiesrdquo Cancer Research vol 65 no 13 pp5506ndash5511 2005
[82] Y Matsumura and D Tarin ldquoSignificance of CD44 geneproducts for cancer diagnosis and disease evaluationrdquo Lancetvol 340 no 8827 pp 1053ndash1058 1992
[83] S Saito H Okabe M Watanabe et al ldquoCD44v6 expressionis related to mesenchymal phenotype and poor prognosis inpatients with colorectal cancerrdquo Oncology Reports vol 29 no4 pp 1570ndash1578 2013
[84] E M Peek D R Li H Zhang et al ldquoStromal modulation ofbladder cancer-initiating cells in a subcutaneous tumor modelrdquoAmerican Journal of Cancer Research vol 2 no 6 pp 745ndash7512012
[85] J Kuncova M Urban and V Mandys ldquoExpression of CD44sand CD44v6 in transitional cell carcinomas of the urinarybladder comparison with tumour grade proliferative activityand p53 immunoreactivity of tumour cellsrdquoAPMIS vol 115 no11 pp 1194ndash1205 2007
[86] M Sugiyama A Woodman T Sugino et al ldquoNon-invasivedetection of bladder cancer by identification of abnormal CD44proteins in exfoliated cancer cells in urinerdquo Journal of ClinicalMolecular Pathology vol 48 no 3 pp M142ndashM147 1995
[87] Y M Yang and J W Chang ldquoBladder cancer initiating cells(BCICs) are among EMAminusCD44v6+ subset novel methods forisolating undetermined cancer stem (initiating) cellsrdquo CancerInvestigation vol 26 no 7 pp 725ndash733 2008
[88] R Thanan S Oikawa P Yongvanit et al ldquoInflammation-induced protein carbonylation contributes to poor prognosisfor cholangiocarcinomardquo Free Radical Biology and Medicinevol 52 no 8 pp 1465ndash1472 2012
Oxidative Medicine and Cellular Longevity 3
a cell-free system suggesting that GC to TA transversionscan occur [56] In the ONOOminus-treated supF shuttle vectorwhich was replicated in host Escherichia coli cells the major-ity of mutations occurred at GC base pairs predominantlyinvolvingGC toTA transversions [57]Thus 8-nitroguanineis a potentially mutagenic DNA lesion that can participate ininitiation and promotion in infection-related carcinogenesis
Wehave investigated the formation of 8-nitroguanine and8-oxodG in various clinical specimens and animal modelsin relation to inflammation-related carcinogenesis as sum-marized in Table 1 It is noteworthy that DNA damage wasspecifically induced at sites of carcinogenesis under chronicinfection and various inflammatory conditions as reviewedpreviously [2 3] It has been estimated that 11 infectiousagents are carcinogenic to humans (Group 1) by IARC par-asites (Schistosoma haematobium (SH) Opisthorchis viver-rini (OV) and Clonorchis sinensis (CS)) viruses (hepatitisB and C virus (HBV and HCV) human papillomavirus(HPV) Epstein-Barr virus (EBV) humanT-cell lymphotrop-ic virus (HTLV-1) Kaposirsquos sarcoma herpesvirus (KSHV)and human immunodeficiency virus-1 (HIV-1)) and bac-terium Helicobacter pylori (HP) [4 58] We demonstratedthat 8-nitroguaninewas strongly formed via iNOS expressionat related cancer sites of SH OV HBV HCV HPV EBVand HP [2 3 10 11] The IARC classification of CS hasbeen recently updated from 2A to 1 so we have not yetcollected enough data for 8-nitroguanine The mechanismof carcinogenesis by HTLV-1 KSHV or HIV-1 seems notto be associative to inflammation We could not observe 8-nitroguanine in leukaemia samples from patients infectedwith HTLV-1 (data not shown) 8-Nitroguanine was alsoformed in tissues from patients with inflammatory diseasessuch as inflammatory bowel diseases (IBD) Lichen planus(LP) and Barrettrsquos esophagus (BE) [3 38] Recently wehave reported that the formation of 8-nitroguanine and8-oxodG increased significantly in the order of Barrettrsquosesophageal adenocarcinoma gt Barrettrsquos esophagus gt normaltissues Treatment of BEpatientswith proton pump inhibitors(PPIs) which is expected to reduce the risk of Barrettrsquosesophageal adenocarcinoma suppressed these DNA lesionsprobably via activation of an antioxidant enzyme Mn-SOD[38] Regarding inflammation-related carcinogenesis withoutinfection we describe the formation of 8-nitroguanine inlung tissues of mice intratracheally administered asbestos[42] although the precise mechanism of nitrative DNAdamage remains to be clarified Nitrative stress is involved inthe asbestos-derived inflammatory response via myeloperox-idase [59ndash62] that plays a significant role in asbestos-inducedcarcinogenesis [63] Interestingly immunoreactivities of 8-nitroguanine iNOS andNF-120581B significantly increased in theorder of carcinogenic potential crocidolite (blue asbestos) gtchrysotile (white asbestos) gt control [42]
On the basis of our studies various pathogenic factorsinduce inflammatory responses and the production of ROSand RNS from inflammatory and epithelial cells via iNOSexpression which is regulated by transcriptional factorsincluding NF-120581B STAT and HIF-1120572 [2 3] Oxidative andnitrative stresses cause DNA damage contributing to theaccumulation of genetic alterations in tissues throughout
the carcinogenic process Particularly 8-nitroguanine for-mation may participate in inflammation-related carcinogen-esis as a common mechanism Therefore 8-nitroguaninecould be used as a potential biomarker of inflammation-related carcinogenesis Importantly experimental evidencehas suggested that 8-nitroguanine can lead to mutationspreferentially GC to TA transversions [46 64] in additionto 8-oxodG [9 65] Indeed GC to TA transversions havebeen observed in vivo in the ras gene [66] and the p53tumor suppressor gene in lung and liver cancer [67 68]We also revealed that 8-nitroguanine and 8-oxodG wereapparently formed in adenocarcinoma caused by mutatedK-ras by using conditional transgenic mice with K-rasV11988611989712[69] 8-Nitroguanine was colocalized with iNOS NF-120581BIKK MAPK MEK and mutated K-ras suggesting thatoncogenic K-ras causes additional DNAdamage via signalingpathways involving these molecules It is noteworthy thatK-ras mutation mediates not only cell overproliferation butalso the accumulation of mutagenic DNA lesions leadingto carcinogenesis These findings imply that DNA damagemediated by ROS and RNS may participate in carcinogenesisvia activation of protooncogenes and inactivation of tumorsuppressor genes
2 Cancer Stem Cell Markers inInflammation-Related Carcinogenesis
The cancer stem cell concept is widely accepted as importantfor overcoming cancer Several studies have revealed that can-cer cells show accumulation of mutations genetic instabilityand epigenetic change suggesting that cancer is also a diseaseof genes [70]Themost important question is how to generatecancer stem cells Recently many studies have reported onthe expressions of stemness cell markers in various kindsof cancer Table 1 summarizes possible markers of cancerstem cells especially related to each inflammatory causativeagent We reported that 8-nitroguanine was strongly formedat all of these cancer sites from animals and patients withinfectious agents inflammatory diseases and exposure toasbestos Importantly we also detected colocalization of8-nitroguanine and stemness marker in infection-relatedcarcinogenesis as mentioned in the next section On thebasis of our recent studies it is considered that chronicinflammation can increase mutagenic DNA lesions throughROSRNS generation and can promote proliferation via stemcells activation for tissue regeneration This idea is alsosupported by other papers about the association of cancerstem cells with infection and inflammation [71ndash74]
3 DNA Damage and MutantStem Cells Induced bySchistosoma haematobium Infection
Chronic infection with SH is associated with urinary bladdercancer [76] Contact with contaminated freshwater is themajor risk factor for infection SH-associated bladder canceris a common malignancy especially in the Middle East andAfrica It is believed that the parasitersquos eggs in the host
4 Oxidative Medicine and Cellular Longevity
8-Nitroguanine Oct34 Merged
Nor
mal
Cysti
tis (S
H+)
Canc
er (S
H+
)Ca
ncer
(SHminus
)
Figure 1The formation of 8-nitroguanine (red) and the expression of Oct34 (green) were assessed by double immunofluorescence staining[10] In the merged image co-localization of 8-nitroguanine and Oct34 is indicated in yellow Original magnification in all pictures is 200x(SH Schistosoma haematobium) Formalin-fixed and paraffin-embedded biopsy and surgical specimens were obtained from normal subjectsand patients with SH-induced cystitis and bladder cancer Normal tissues and urinary bladder cancer tissues without SH infection wereobtained from a commercial urinary bladder tissue array (Biomaxus USA) Normal tissues with cystitis were excluded SH-egg antigens insera were detected by Sandwich ELISA assay [75] This study was performed in accordance with the Ethical Guidelines for EpidemiologicalResearch enacted by the Japanese government Deparaffinized and antigen-retrieved sections were incubated first with 5 skim milk andthen with a rabbit polyclonal anti-8-nitroguanine antibody (2 120583gmL prepared as described previously [11]) and mouse monoclonal anti-Oct34 antibody (2120583gmL Santa Cruz Biotechnology CA USA) overnight at room temperature The sections were then incubated for 3 hwith Alexa 594-labeled goat antibody against rabbit IgG and Alexa 488-labeled goat antibody against mouse IgG (each 1 400 MolecularProbes Eugene OR USA)
bladder result in irritation eventual fibrosis and chronic cys-titis leading to carcinogenesis To investigate whether oxida-tive and nitrative DNA damage participate in inflammation-related carcinogenesis we performed immunohistochemicalanalysis using bladder tissues obtained from cystitis and blad-der cancer patients infected with SH We demonstrated forthe first time that 8-nitroguanine is formed in the tumors ofbladder cancer patients with SH infection [10]The formationof 8-nitroguanine and 8-oxodG was significantly higher inbladder cancer and cystitis tissues than in normal tissuesOxidative DNA damage and SH infection were stronglycorrelated [10 77] iNOS expression was co-localized withNF-120581B in 8-nitroguanine-positive tumor cells from bladdercancer patients NF-120581B can be activated by TNF-120572 a majormediator of inflammation which has been reported toincrease in peripheral bloodmononuclear cells stimulated bySH egg antigen [78] It is reasonable to conclude that both8-nitroguanine and 8-oxodG are formed by iNOS-mediatedNO overproduction via NF-120581B activation under SH-causedchronic inflammation
A stemness marker Oct34 is generally expressed in plu-ripotent embryonic stem and germ cells [79] Expression
of Oct34 is reportedly necessary for maintaining the self-renewing cancer stem-like and chemoradioresistant proper-ties of tumorigenic stem-like cell populations [80 81] and isthus considered to play roles in the carcinogenesis processAnother stemness marker CD44 has been identified asa cell surface marker associated with cancer stem cells inseveral types of tumors [82 83] including urinary bladdercancer [84] Expression of CD44v6 a splicing variant ofCD44 is correlated with proliferation of poorly differentiatedurothelial cells and the characteristic phenotype of tumor-initiating bladder cancer stem cells [85ndash87] Our previousreports show that different risk factors induce differentlevels of expression of stemness markers in urinary bladdercarcinoma SH-induced urinary bladder cancer correlateswith the expression of Oct34 [10] while urinary bladdercancer without the infection correlates with the expressionof CD44v6 [11] Moreover 8-nitroguanine was formed inOct34-positive stem cells in SH-associated cystitis and can-cer tissues [10] as shown in Figure 1 Inflammation by SHinfection may increase the number of mutant stem cellsin which iNOS-dependent DNA damage occurs via NF-120581Bactivation leading to tumor development
Figure 2 Postulated mechanism for generating cancer stem cells by inflammation
4 DNA Damage and Mutant Stem CellsInduced by Opisthorchis viverrini Infection
Chronic infection with the liver fluke OV is associatedwith cholangiocarcinomas [58] Infection with this para-site is repeatedly caused by eating raw fish containing theinfective stage of the fluke We have demonstrated that 8-nitroguanine is formed in relation to inflammation-relatedcarcinogenesis using an animal model [12ndash15] 8-OxodGand 8-nitroguanine were formed in inflammatory cells andepithelium of bile ducts and their formation increased in amanner dependent on infection timesThe anthelmintic drugpraziquantel dramatically diminished these DNA lesions andiNOS expression in OV-infected hamsters Thus repeatedOV-infection can induce the iNOS expression in bile ductsand subsequently cause nitrative and oxidative damage tonucleic acids which may participate in cholangiocarcinoma
In our study with patients the formation of 8-oxodGand 8-nitroguanine occurred to a much greater extent incancerous tissue than in noncancerous tissue in intrahepaticcholangiocarcinoma patients indicating that these DNAlesions contribute to tumor progression [16] Our proteomicstudy showed that carbonylation of serotransferrin and heatshock protein 70 kDa protein 1 (HSP701) is significantlyassociated with poor prognoses [88] Carbonylation of pro-tein is an irreversible modification induced by oxidativestress We have proposed that carbonylations of serotrans-ferrin and HSP701 may induce oxidative stress by iron-accumulation and dysfunction of antioxidative propertyleading to increased oxidative DNA damage and progressionof cholangiocarcinoma
Recently we observed high expression and co-locali-zation of hepatocyte marker and cholangiocyte marker inOV-associated cholangiocarcinoma patients suggesting the
6 Oxidative Medicine and Cellular Longevity
involvement of stem cells in cholangiocarcinoma develop-ment [17] Cholangiocarcinoma tissues with positive stem-ness markers (CD133 or Oct34) showed significantly lowerexpression of antioxidant enzyme Mn-SOD and significantlyhigher levels of 8-oxodG 8-nitroguanine and DNA damageresponse protein 120574-H2AX Moreover CD133- and Oct34-positive cholangiocarcinoma patients had significant associa-tionswith tumor histology types tumor stage and poor prog-noses These findings suggest that CD133 and Oct34 in cho-langiocarcinoma are highly associated with formation ofDNA lesions whichmay be involved in genetic instability andlead to tumor development with aggressive clinical featuresIn our study proliferating cell nuclear antigen (PCNA)accumulated in the epithelium of bile ducts of hamsters afterrepeated OV infection supporting the hypothesis that cellproliferation is promoted by inflammation-mediated DNAdamage [14] Inflammation by OV infection may increasethe number of mutant stem cell in which oxidative stressessuch as carbonylation of proteins and oxidativeDNAdamageand cell proliferation are promoted leading to progression ofcholangiocarcinoma
5 Conclusions
Nitrative and oxidative DNA lesions with mutagenic proper-ties are formed in various types of inflammation-related can-cer tissuesWehave proposed amechanism for the generationof cancer stem cells by inflammation in Figure 2 Chronicinflammation by infectious agents inflammatory diseasesand other factors causes various types of damage to nucleicacids proteins tissue and so on via ROSRNS generationTissue injury under chronic inflammation may activate pro-genitorstem cells for regeneration In these cells ROSRNSfrom inflammation can cause multiple mutations whichmaygenerate mutant stem cells and cancer stem cells leadingto carcinogenesis Indeed 8-nitroguanine was formed instemness marker-positive cells in parasite-associated cancertissues The mechanism for generation of cancer stem cellswill be explained by our ongoing studies on the formation of8-nitroguanine in stem-like cells of target tissues associatedwith other inflammation-related cancers
Conflict of Interests
The authors declare that they have no conflict of interests
Acknowledgment
This work was supported by a grant-in-aid from theMinistryof Education Culture Sports Science and Technology ofJapan
References
[1] L M Coussens and Z Werb ldquoInflammation and cancerrdquoNature vol 420 no 6917 pp 860ndash867 2002
[2] S Kawanishi and Y Hiraku ldquoOxidative and nitrative DNAdamage as biomarker for carcinogenesis with special reference
to inflammationrdquo Antioxidants and Redox Signaling vol 8 no5-6 pp 1047ndash1058 2006
[3] M Murata R Thanan N Ma and S Kawanishi ldquoRole ofnitrative and oxidative DNA damage in inflammation-relatedcarcinogenesisrdquo Journal of Biomedicine and Biotechnology vol2012 Article ID 623019 11 pages 2012
[4] IARC ldquoChronic infectionsrdquo in World Cancer Report B WStewart and P Kleihues Eds pp 128ndash135 IARC Press LyonFrance 2008
[5] S P Hussain and C C Harris ldquoInflammation and canceran ancient link with novel potentialsrdquo International Journal ofCancer vol 121 no 11 pp 2373ndash2380 2007
[6] A J Schetter N H Heegaard and C C Harris ldquoInflammationand cancer interweaving microRNA free radical cytokine andp53 pathwaysrdquo Carcinogenesis vol 31 no 1 Article ID bgp272pp 37ndash49 2010
[7] H Ohshima M Tatemichi and T Sawa ldquoChemical basis ofinflammation-induced carcinogenesisrdquo Archives of Biochem-istry and Biophysics vol 417 no 1 pp 3ndash11 2003
[8] S Kawanishi Y Hiraku and S Oikawa ldquoMechanism ofguanine-specific DNA damage by oxidative stress and its rolein carcinogenesis and agingrdquoMutation Research vol 488 no 1pp 65ndash76 2001
[9] S D Bruner D P G Norman and G L Verdine ldquoStructuralbasis for recognition and repair of the endogenous mutagen 8-oxoguanine in DNArdquo Nature vol 403 no 6772 pp 859ndash8662000
[10] N Ma R Thanan H Kobayashi et al ldquoNitrative DNA damageand Oct34 expression in urinary bladder cancer with Schis-tosoma haematobium infectionrdquo Biochemical and BiophysicalResearch Communications vol 414 no 2 pp 344ndash349 2011
[11] R Thanan M Murata N Ma et al ldquoNuclear localization ofCOX-2 in relation to the expression of stemness markers inurinary bladder cancerrdquo Mediators of Inflammation vol 2012Article ID 165879 8 pages 2012
[12] S Pinlaor Y Hiraku P Yongvanit et al ldquoiNOS-dependentDNA damage via NF-120581B expression in hamsters infected withOpisthorchis viverrini and its suppression by the antihelminthicdrug praziquantelrdquo International Journal of Cancer vol 119 no5 pp 1067ndash1072 2006
[13] S Pinlaor Y Hiraku NMa et al ldquoMechanism of NO-mediatedoxidative and nitrative DNA damage in hamsters infectedwithOpisthorchis viverrini a model of inflammation-mediatedcarcinogenesisrdquo Nitric Oxide vol 11 no 2 pp 175ndash183 2004
[14] S Pinlaor N Ma Y Hiraku et al ldquoRepeated infection withOpisthorchis viverrini induces accumulation of 8-nitroguanineand 8-oxo-78-dihydro-21015840-deoxyguanine in the bile duct ofhamsters via inducible nitric oxide synthaserdquo Carcinogenesisvol 25 no 8 pp 1535ndash1542 2004
[15] S Pinlaor P Yongvanit YHiraku et al ldquo8-Nitroguanine forma-tion in the liver of hamsters infectedwithOpisthorchis viverrinirdquoBiochemical and Biophysical Research Communications vol 309no 3 pp 567ndash571 2003
[16] S Pinlaor B Sripa N Ma et al ldquoNitrative and oxidative DNAdamage in intrahepatic cholangiocarcinoma patients in relationto tumor invasionrdquo World Journal of Gastroenterology vol 11no 30 pp 4644ndash4649 2005
[17] R Thanan C Pairojkul S Pinlaor et al ldquoInflammation-related DNA damage and expression of CD133 and Oct34 incholangiocarcinoma patients with poor prognosisrdquo Free RadicalBiology amp Medicine 2013
Oxidative Medicine and Cellular Longevity 7
[18] S Horiike S Kawanishi M Kaito et al ldquoAccumulation of 8-nitroguanine in the liver of patients with chronic hepatitis CrdquoJournal of Hepatology vol 43 no 3 pp 403ndash410 2005
[19] N Ali H Allam R May et al ldquoHepatitis C virus-inducedcancer stem cell-like signatures in cell culture and murinetumor xenograftsrdquo Journal of Virology vol 85 no 23 pp 12292ndash12303 2011
[20] K Machida H Tsukamoto H Mkrtchyan et al ldquoToll-likereceptor 4 mediates synergism between alcohol and HCVin hepatic oncogenesis involving stem cell marker NanogrdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 106 no 5 pp 1548ndash1553 2009
[21] Y Hiraku T Tabata N Ma M Murata X Ding and SKawanishi ldquoNitrative and oxidative DNA damage in cervicalintraepithelial neoplasia associatedwith humanpapilloma virusinfectionrdquo Cancer Science vol 98 no 7 pp 964ndash972 2007
[22] S-K Kim H-S Shim K-G Lee H-J An K-R Lee andN-H Cho ldquoGlassy cell carcinoma predominantly commits toa squamous lineage and is strongly associated with high-risktype human papillomavirus infectionrdquo International Journal ofGynecological Pathology vol 28 no 4 pp 389ndash395 2009
[23] S Regauer and O Reich ldquoCK17 and p16 expression pat-terns distinguish (atypical) immature squamous metaplasiafrom high-grade cervical intraepithelial neoplasia (CIN III)rdquoHistopathology vol 50 no 5 pp 629ndash635 2007
[24] W-K Liu Y-L Chu F Zhang et al ldquoThe relationship betweenHPV16 and expression of CD44v6 nm23H1 in esophagealsquamous cell carcinomardquo Archives of Virology vol 150 no 5pp 991ndash1001 2005
[25] D Liu P Zhou L Zhang et al ldquoHDAC1DNMT3A-containingcomplex is associated with suppression of Oct4 in cervicalcancer cellsrdquo Biochemistry vol 77 no 8 pp 934ndash940 2012
[26] N Ma M Kawanishi Y Hiraku et al ldquoReactive nitrogenspecies-dependent DNA damage in EBV-associated nasopha-ryngeal carcinoma the relation to STAT3 activation and EGFRexpressionrdquo International Journal of Cancer vol 122 no 11 pp2517ndash2525 2008
[27] Q-L Kong L-J Hu J-Y Cao et al ldquoEpstein-barr virus-encoded LMP2A induces an epithelialmdashmesenchymal transi-tion and increases the number of side population stem-likecancer cells in nasopharyngeal carcinomardquo PLoS Pathogens vol6 no 6 Article ID e1000940 2010
[28] A Dutton C B Woodman M B Chukwuma et al ldquoBmi-1 isinduced by the Epstein-Barr virus oncogene LMP1 and regulatesthe expression of viral target genes inHodgkin lymphoma cellsrdquoBlood vol 109 no 6 pp 2597ndash2603 2007
[29] N Ma Y Adachi Y Hiraku et al ldquoAccumulation of 8-nitroguanine in human gastric epithelium induced by Heli-cobacter pylori infectionrdquo Biochemical and Biophysical ResearchCommunications vol 319 no 2 pp 506ndash510 2004
[30] M Katsurahara Y Kobayashi M Iwasa et al ldquoReactivenitrogen species mediate DNA damage in helicobacter pylori-infected gastric mucosardquo Helicobacter vol 14 no 6 pp 552ndash558 2009
[31] Y Fujii K Yoshihashi H Suzuki et al ldquoCDX1 confers intestinalphenotype on gastric epithelial cells via induction of stemness-associated reprogramming factors SALL4 and KLF5rdquo Proceed-ings of the National Academy of Sciences of USA vol 109 no 50pp 20584ndash10589 2012
[32] J M Noto T Khizanishvili R Chaturvedi et al ldquoHelicobacterpylori promotes the expression of Kruppel-like factor 5
a mediator of carcinogenesis in vitro and in vivordquo PLoS Onevol 8 no 1 Article ID e54344 2013
[33] T Uehara D Ma Y Yao et al ldquoH pylori infection is associatedwith DNA damage of Lgr5-positive epithelial stem cells in thestomach of patients with gastric cancerrdquo Digestive Diseases andSciences vol 58 no 1 pp 140ndash149 2013
[34] X Ding Y Hiraku N Ma et al ldquoInducible nitric oxidesynthase-dependent DNA damage in mouse model of inflam-matory bowel diseaserdquoCancer Science vol 96 no 3 pp 157ndash1632005
[35] P Chaiyarit N Ma Y Hiraku et al ldquoNitrative and oxidativeDNA damage in oral lichen planus in relation to human oralcarcinogenesisrdquoCancer Science vol 96 no 9 pp 553ndash559 2005
[36] L Ma H Wang H Yao L Zhu W Liu and Z Zhou ldquoBmi1expression in oral lichen planus and the risk of progression tooral squamous cell carcinomardquo Annals of Diagnostic Pathologyvol 17 no 4 pp 327ndash330 2013
[37] A Bose M T Teh I L Hutchison H Wan I M Leigh andA Waseem ldquoTwo mechanisms regulate keratin K15 expressionin keratinocytes role of PKCAP-1 and FOXM1 mediatedsignallingrdquo PLoS One vol 7 no 6 Article ID e38599 2012
[38] RThanan NMa K Iijima et al ldquoProton pump inhibitors sup-press iNOS-dependent DNA damage in Barrettrsquos esophagus byincreasing Mn-SOD expressionrdquo Biochemical and BiophysicalResearch Communications vol 421 no 2 pp 280ndash285 2012
[39] J Mendelson S Song Y Li et al ldquoDysfunctional transform-ing growth factor-120573 signaling with constitutively active notchsignaling in Barrettrsquos esophageal adenocarcinomardquo Cancer vol117 no 16 pp 3691ndash3702 2011
[40] J Ahmad K Arthur P Maxwell et al ldquoRe grotenhuis et alBarrettrsquos oesophageal adenocarcinoma encompasses tumour-initiating cells that do not express common cancer stem cellmarkers J Pathol 2010 221 379ndash389rdquo Journal of Pathology vol224 no 1 pp 143ndash145 2011
[41] Y V Bobryshev A K Freeman N K Botelho D Tran AJ M Levert-Mignon and R V N Lord ldquoExpression of theputative stem cell marker Musashi-1 in Barrettrsquos esophagus andesophageal adenocarcinomardquoDiseases of the Esophagus vol 23no 7 pp 580ndash589 2010
[42] Y Hiraku S Kawanishi T Ichinose and M Murata ldquoThe roleof iNOS-mediated DNA damage in infection- and asbestos-induced carcinogenesisrdquo Annals of the New York Academy ofSciences vol 1203 pp 15ndash22 2010
[43] D Fukumura S Kashiwagi and R K Jain ldquoThe role of nitricoxide in tumour progressionrdquoNature Reviews Cancer vol 6 no7 pp 521ndash534 2006
[44] P K Lala and C Chakraborty ldquoRole of nitric oxide in carcino-genesis and tumour progressionrdquo Lancet Oncology vol 2 no 3pp 149ndash156 2001
[45] S Wang Z Liu L Wang and X Zhang ldquoNF-120581B signalingpathway inflammation and colorectal cancerrdquo Chinese Journalof Cellular andMolecular Immunology vol 6 no 5 pp 327ndash3342009
[46] V Yermilov J Rubio M Becchi M D Friesen B Pignatelliand H Ohshima ldquoFormation of 8-nitroguanine by the reactionof guanine with peroxynitrite in vitrordquo Carcinogenesis vol 16no 9 pp 2045ndash2050 1995
[47] B Halliwell ldquoOxygen and nitrogen are pro-carcinogens Dam-age to DNA by reactive oxygen chlorine and nitrogen speciesmeasurement mechanism and the effects of nutritionrdquo Muta-tion Research vol 443 no 1-2 pp 37ndash52 1999
8 Oxidative Medicine and Cellular Longevity
[48] R S Sodum and E S Fiala ldquoAnalysis of peroxynitrite reactionswith guanine xanthine and adenine nucleosides by high-pressure liquid chromatography with electrochemical detec-tion C8-nitration and -oxidationrdquo Chemical Research in Toxi-cology vol 14 no 4 pp 438ndash450 2001
[49] T Akaike S Fujii A Kato et al ldquoViral mutation acceleratedby nitric oxide production during infection in vivordquoThe FASEBJournal vol 14 no 10 pp 1447ndash1454 2000
[50] N Ma M Murata S Ohnishi R Thanan Y Hiraku and SKawanishi ldquo8-Nitroguanine a potential biomarker to evaluatethe risk of inflammation-related carcinogenesisrdquo in BiomarkerT K Kahn Ed chapter 10 pp 201ndash224 InTech Rijeka Croatia2012
[51] V Yermilov J Rubio and H Ohshima ldquoFormation of 8-nitroguanine in DNA treated with peroxynitrite in vitro and itsrapid removal from DNA by depurinationrdquo The FEBS Lettersvol 376 no 3 pp 207ndash210 1995
[52] L A Loeb and B D Preston ldquoMutagenesis by apurinicapyr-imidinic sitesrdquo Annual Review of Genetics vol 20 pp 201ndash2301986
[53] S Boiteux and M Guillet ldquoAbasic sites in DNA repair andbiological consequences in Saccharomyces cerevisiaerdquo DNARepair vol 3 no 1 pp 1ndash12 2004
[54] J E Sale A R Lehmann and R Woodgate ldquoY-family DNApolymerases and their role in tolerance of cellular DNA dam-agerdquo Nature Reviews Molecular Cell Biology vol 13 no 3 pp141ndash152 2012
[55] X Wu K Takenaka E Sonoda et al ldquoCritical roles forpolymerase 120577 in cellular tolerance to nitric oxide-induced DNAdamagerdquo Cancer Research vol 66 no 2 pp 748ndash754 2006
[56] N Suzuki M Yasui N E Geacintov V Shafirovich and SShibutani ldquoMiscoding events during DNA synthesis past thenitration-damaged base 8-nitroguaninerdquo Biochemistry vol 44no 25 pp 9238ndash9245 2005
[57] M Y Kim M Dong P C Dedon and G N Wogan ldquoEffects ofperoxynitrite dose and dose rate onDNAdamage andmutationin the supF shuttle vectorrdquo Chemical Research in Toxicology vol18 no 1 pp 76ndash86 2005
[58] IARC ldquoOpisthorchis viverrini and Clonorchis sinensisrdquo in AReview of Human CarcInogens Biological Agents vol 100B ofIARC Monographs on the Evaluation of Carcinogenic Risks toHumans pp 347ndash376 IARC Press Lyon France 2012
[59] J P EiserichM Hristova C E Cross et al ldquoFormation of nitricoxide-derived inflammatory oxidants by myeloperoxidase inneutrophilsrdquo Nature vol 391 no 6665 pp 393ndash397 1998
[60] J P Gaut J Byun H D Tran et al ldquoMyeloperoxidase producesnitrating oxidants in vivordquo Journal of Clinical Investigation vol109 no 10 pp 1311ndash1319 2002
[61] S Tanaka N Choe D R Hemenway S Zhu S Matalon andE Kagan ldquoAsbestos inhalation induces reactive nitrogen speciesand nitrotyrosine formation in the lungs and pleura of the ratrdquoJournal of Clinical Investigation vol 102 no 2 pp 445ndash4541998
[62] A Van Der Vliet J P Eiserich M K Shigenaga and C ECross ldquoReactive nitrogen species and tyrosine nitration in therespiratory tract epiphenomena or a pathobiologic mechanismof diseaserdquo American Journal of Respiratory and Critical CareMedicine vol 160 no 1 pp 1ndash9 1999
[63] A Haegens A Van Der Vliet K J Butnor et al ldquoAsbestos-induced lung inflammation and epithelial cell proliferation arealtered in myeloperoxidase-null micerdquoCancer Research vol 65no 21 pp 9670ndash9677 2005
[64] N Suzuki M Yasui N E Geacintov V Shafirovich and SShibutani ldquoMiscoding events during DNA synthesis past thenitration-damaged base 8-nitroguaninerdquo Biochemistry vol 44no 25 pp 9238ndash9245 2005
[65] S Shibutani M Takeshita and A P Grollman ldquoInsertionof specific bases during DNA synthesis past the oxidation-damaged base 8-oxodGrdquoNature vol 349 no 6308 pp 431ndash4341991
[66] J L Bos ldquoThe ras gene family and human carcinogenesisrdquoMutation Research vol 195 no 3 pp 255ndash271 1988
[67] S P Hussain L J Hofseth and C C Harris ldquoRadical causes ofcancerrdquoNature Reviews Cancer vol 3 no 4 pp 276ndash285 2003
[68] T Takahashi M M Nau I Chiba et al ldquop53 a frequent targetfor genetic abnormalities in lung cancerrdquo Science vol 246 no4929 pp 491ndash494 1989
[69] S Ohnishi H Saito N Suzuki et al ldquoNitrative and oxidativeDNA damage caused by K-ras mutation in micerdquo Biochemicaland Biophysical Research Communications vol 413 no 2 pp236ndash240 2011
[70] M Shipitsin and K Polyak ldquoThe cancer stem cell hypothesisin search of definitions markers and relevancerdquo LaboratoryInvestigation vol 88 no 5 pp 459ndash463 2008
[71] S Sell ldquoInfection stem cells and cancer signalsrdquo Current Phar-maceutical Biotechnology vol 12 no 2 pp 182ndash188 2011
[72] S Reuter S C Gupta M M Chaturvedi and B B AggarwalldquoOxidative stress inflammation and cancer how are theylinkedrdquo Free Radical Biology and Medicine vol 49 no 11 pp1603ndash1616 2010
[73] Y Jing Z Han Y Liu et al ldquoMesenchymal stem cellsin inflammation microenvironment accelerates hepatocellu-lar carcinoma metastasis by inducing epithelial-mesenchymaltransitionrdquo PLoS One vol 7 no 8 Article ID e43272 2012
[74] N J Maitland and A T Collins ldquoInflammation as the primaryaetiological agent of human prostate cancer a stem cell con-nectionrdquo Journal of Cellular Biochemistry vol 105 no 4 pp931ndash939 2008
[75] Z A Shaker M A Kaddah S B Hanallah and M I El-Khodary ldquoProduction of monoclonal antibodies against targetschistosomal antigen secreted in the urine of schistosomamansoni-infected patientsrdquo International Journal for Parasitol-ogy vol 28 no 12 pp 1893ndash1901 1998
[76] IARC ldquoSchistosoma haematobiumrdquo in A Review of HumanCarcInogens Biological Agents vol 100B of IARC Monographson the Evaluation of Carcinogenic Risks to Humans pp 371ndash384IARC Press Lyon France 2012
[77] E I Salim K Morimura A Menesi M El-Lity S Fukushimaand HWanibuchi ldquoElevated oxidative stress and DNA damageand repair levels in urinary bladder carcinomas associated withschistosomiasisrdquo International Journal of Cancer vol 123 no 3pp 601ndash608 2008
[78] A N Wamachi J S Mayadev P L Mungai et al ldquoIncreasedratio of tumor necrosis factor-120572 to interleukin-10 productionis associated with Schistosoma haematobium-induced urinary-tract morbidityrdquo Journal of Infectious Diseases vol 190 no 11pp 2020ndash2030 2004
[79] L H Looijenga H Stoop H P De Leeuw et al ldquoPOU5F1(OCT34) identifies cells with pluripotent potential in humangerm cell tumorsrdquo Cancer Research vol 63 no 9 pp 2244ndash2250 2003
[80] Y-C Chen H-S Hsu Y-W Chen et al ldquoOct-4 expressionmaintained cancer stem-like properties in lung cancer-derived
Oxidative Medicine and Cellular Longevity 9
CD133-positive cellsrdquo PLoS One vol 3 no 7 Article ID e26372008
[81] D Ponti A Costa N Zaffaroni et al ldquoIsolation and in vitropropagation of tumorigenic breast cancer cells with stempro-genitor cell propertiesrdquo Cancer Research vol 65 no 13 pp5506ndash5511 2005
[82] Y Matsumura and D Tarin ldquoSignificance of CD44 geneproducts for cancer diagnosis and disease evaluationrdquo Lancetvol 340 no 8827 pp 1053ndash1058 1992
[83] S Saito H Okabe M Watanabe et al ldquoCD44v6 expressionis related to mesenchymal phenotype and poor prognosis inpatients with colorectal cancerrdquo Oncology Reports vol 29 no4 pp 1570ndash1578 2013
[84] E M Peek D R Li H Zhang et al ldquoStromal modulation ofbladder cancer-initiating cells in a subcutaneous tumor modelrdquoAmerican Journal of Cancer Research vol 2 no 6 pp 745ndash7512012
[85] J Kuncova M Urban and V Mandys ldquoExpression of CD44sand CD44v6 in transitional cell carcinomas of the urinarybladder comparison with tumour grade proliferative activityand p53 immunoreactivity of tumour cellsrdquoAPMIS vol 115 no11 pp 1194ndash1205 2007
[86] M Sugiyama A Woodman T Sugino et al ldquoNon-invasivedetection of bladder cancer by identification of abnormal CD44proteins in exfoliated cancer cells in urinerdquo Journal of ClinicalMolecular Pathology vol 48 no 3 pp M142ndashM147 1995
[87] Y M Yang and J W Chang ldquoBladder cancer initiating cells(BCICs) are among EMAminusCD44v6+ subset novel methods forisolating undetermined cancer stem (initiating) cellsrdquo CancerInvestigation vol 26 no 7 pp 725ndash733 2008
[88] R Thanan S Oikawa P Yongvanit et al ldquoInflammation-induced protein carbonylation contributes to poor prognosisfor cholangiocarcinomardquo Free Radical Biology and Medicinevol 52 no 8 pp 1465ndash1472 2012
4 Oxidative Medicine and Cellular Longevity
8-Nitroguanine Oct34 Merged
Nor
mal
Cysti
tis (S
H+)
Canc
er (S
H+
)Ca
ncer
(SHminus
)
Figure 1The formation of 8-nitroguanine (red) and the expression of Oct34 (green) were assessed by double immunofluorescence staining[10] In the merged image co-localization of 8-nitroguanine and Oct34 is indicated in yellow Original magnification in all pictures is 200x(SH Schistosoma haematobium) Formalin-fixed and paraffin-embedded biopsy and surgical specimens were obtained from normal subjectsand patients with SH-induced cystitis and bladder cancer Normal tissues and urinary bladder cancer tissues without SH infection wereobtained from a commercial urinary bladder tissue array (Biomaxus USA) Normal tissues with cystitis were excluded SH-egg antigens insera were detected by Sandwich ELISA assay [75] This study was performed in accordance with the Ethical Guidelines for EpidemiologicalResearch enacted by the Japanese government Deparaffinized and antigen-retrieved sections were incubated first with 5 skim milk andthen with a rabbit polyclonal anti-8-nitroguanine antibody (2 120583gmL prepared as described previously [11]) and mouse monoclonal anti-Oct34 antibody (2120583gmL Santa Cruz Biotechnology CA USA) overnight at room temperature The sections were then incubated for 3 hwith Alexa 594-labeled goat antibody against rabbit IgG and Alexa 488-labeled goat antibody against mouse IgG (each 1 400 MolecularProbes Eugene OR USA)
bladder result in irritation eventual fibrosis and chronic cys-titis leading to carcinogenesis To investigate whether oxida-tive and nitrative DNA damage participate in inflammation-related carcinogenesis we performed immunohistochemicalanalysis using bladder tissues obtained from cystitis and blad-der cancer patients infected with SH We demonstrated forthe first time that 8-nitroguanine is formed in the tumors ofbladder cancer patients with SH infection [10]The formationof 8-nitroguanine and 8-oxodG was significantly higher inbladder cancer and cystitis tissues than in normal tissuesOxidative DNA damage and SH infection were stronglycorrelated [10 77] iNOS expression was co-localized withNF-120581B in 8-nitroguanine-positive tumor cells from bladdercancer patients NF-120581B can be activated by TNF-120572 a majormediator of inflammation which has been reported toincrease in peripheral bloodmononuclear cells stimulated bySH egg antigen [78] It is reasonable to conclude that both8-nitroguanine and 8-oxodG are formed by iNOS-mediatedNO overproduction via NF-120581B activation under SH-causedchronic inflammation
A stemness marker Oct34 is generally expressed in plu-ripotent embryonic stem and germ cells [79] Expression
of Oct34 is reportedly necessary for maintaining the self-renewing cancer stem-like and chemoradioresistant proper-ties of tumorigenic stem-like cell populations [80 81] and isthus considered to play roles in the carcinogenesis processAnother stemness marker CD44 has been identified asa cell surface marker associated with cancer stem cells inseveral types of tumors [82 83] including urinary bladdercancer [84] Expression of CD44v6 a splicing variant ofCD44 is correlated with proliferation of poorly differentiatedurothelial cells and the characteristic phenotype of tumor-initiating bladder cancer stem cells [85ndash87] Our previousreports show that different risk factors induce differentlevels of expression of stemness markers in urinary bladdercarcinoma SH-induced urinary bladder cancer correlateswith the expression of Oct34 [10] while urinary bladdercancer without the infection correlates with the expressionof CD44v6 [11] Moreover 8-nitroguanine was formed inOct34-positive stem cells in SH-associated cystitis and can-cer tissues [10] as shown in Figure 1 Inflammation by SHinfection may increase the number of mutant stem cellsin which iNOS-dependent DNA damage occurs via NF-120581Bactivation leading to tumor development
Figure 2 Postulated mechanism for generating cancer stem cells by inflammation
4 DNA Damage and Mutant Stem CellsInduced by Opisthorchis viverrini Infection
Chronic infection with the liver fluke OV is associatedwith cholangiocarcinomas [58] Infection with this para-site is repeatedly caused by eating raw fish containing theinfective stage of the fluke We have demonstrated that 8-nitroguanine is formed in relation to inflammation-relatedcarcinogenesis using an animal model [12ndash15] 8-OxodGand 8-nitroguanine were formed in inflammatory cells andepithelium of bile ducts and their formation increased in amanner dependent on infection timesThe anthelmintic drugpraziquantel dramatically diminished these DNA lesions andiNOS expression in OV-infected hamsters Thus repeatedOV-infection can induce the iNOS expression in bile ductsand subsequently cause nitrative and oxidative damage tonucleic acids which may participate in cholangiocarcinoma
In our study with patients the formation of 8-oxodGand 8-nitroguanine occurred to a much greater extent incancerous tissue than in noncancerous tissue in intrahepaticcholangiocarcinoma patients indicating that these DNAlesions contribute to tumor progression [16] Our proteomicstudy showed that carbonylation of serotransferrin and heatshock protein 70 kDa protein 1 (HSP701) is significantlyassociated with poor prognoses [88] Carbonylation of pro-tein is an irreversible modification induced by oxidativestress We have proposed that carbonylations of serotrans-ferrin and HSP701 may induce oxidative stress by iron-accumulation and dysfunction of antioxidative propertyleading to increased oxidative DNA damage and progressionof cholangiocarcinoma
Recently we observed high expression and co-locali-zation of hepatocyte marker and cholangiocyte marker inOV-associated cholangiocarcinoma patients suggesting the
6 Oxidative Medicine and Cellular Longevity
involvement of stem cells in cholangiocarcinoma develop-ment [17] Cholangiocarcinoma tissues with positive stem-ness markers (CD133 or Oct34) showed significantly lowerexpression of antioxidant enzyme Mn-SOD and significantlyhigher levels of 8-oxodG 8-nitroguanine and DNA damageresponse protein 120574-H2AX Moreover CD133- and Oct34-positive cholangiocarcinoma patients had significant associa-tionswith tumor histology types tumor stage and poor prog-noses These findings suggest that CD133 and Oct34 in cho-langiocarcinoma are highly associated with formation ofDNA lesions whichmay be involved in genetic instability andlead to tumor development with aggressive clinical featuresIn our study proliferating cell nuclear antigen (PCNA)accumulated in the epithelium of bile ducts of hamsters afterrepeated OV infection supporting the hypothesis that cellproliferation is promoted by inflammation-mediated DNAdamage [14] Inflammation by OV infection may increasethe number of mutant stem cell in which oxidative stressessuch as carbonylation of proteins and oxidativeDNAdamageand cell proliferation are promoted leading to progression ofcholangiocarcinoma
5 Conclusions
Nitrative and oxidative DNA lesions with mutagenic proper-ties are formed in various types of inflammation-related can-cer tissuesWehave proposed amechanism for the generationof cancer stem cells by inflammation in Figure 2 Chronicinflammation by infectious agents inflammatory diseasesand other factors causes various types of damage to nucleicacids proteins tissue and so on via ROSRNS generationTissue injury under chronic inflammation may activate pro-genitorstem cells for regeneration In these cells ROSRNSfrom inflammation can cause multiple mutations whichmaygenerate mutant stem cells and cancer stem cells leadingto carcinogenesis Indeed 8-nitroguanine was formed instemness marker-positive cells in parasite-associated cancertissues The mechanism for generation of cancer stem cellswill be explained by our ongoing studies on the formation of8-nitroguanine in stem-like cells of target tissues associatedwith other inflammation-related cancers
Conflict of Interests
The authors declare that they have no conflict of interests
Acknowledgment
This work was supported by a grant-in-aid from theMinistryof Education Culture Sports Science and Technology ofJapan
References
[1] L M Coussens and Z Werb ldquoInflammation and cancerrdquoNature vol 420 no 6917 pp 860ndash867 2002
[2] S Kawanishi and Y Hiraku ldquoOxidative and nitrative DNAdamage as biomarker for carcinogenesis with special reference
to inflammationrdquo Antioxidants and Redox Signaling vol 8 no5-6 pp 1047ndash1058 2006
[3] M Murata R Thanan N Ma and S Kawanishi ldquoRole ofnitrative and oxidative DNA damage in inflammation-relatedcarcinogenesisrdquo Journal of Biomedicine and Biotechnology vol2012 Article ID 623019 11 pages 2012
[4] IARC ldquoChronic infectionsrdquo in World Cancer Report B WStewart and P Kleihues Eds pp 128ndash135 IARC Press LyonFrance 2008
[5] S P Hussain and C C Harris ldquoInflammation and canceran ancient link with novel potentialsrdquo International Journal ofCancer vol 121 no 11 pp 2373ndash2380 2007
[6] A J Schetter N H Heegaard and C C Harris ldquoInflammationand cancer interweaving microRNA free radical cytokine andp53 pathwaysrdquo Carcinogenesis vol 31 no 1 Article ID bgp272pp 37ndash49 2010
[7] H Ohshima M Tatemichi and T Sawa ldquoChemical basis ofinflammation-induced carcinogenesisrdquo Archives of Biochem-istry and Biophysics vol 417 no 1 pp 3ndash11 2003
[8] S Kawanishi Y Hiraku and S Oikawa ldquoMechanism ofguanine-specific DNA damage by oxidative stress and its rolein carcinogenesis and agingrdquoMutation Research vol 488 no 1pp 65ndash76 2001
[9] S D Bruner D P G Norman and G L Verdine ldquoStructuralbasis for recognition and repair of the endogenous mutagen 8-oxoguanine in DNArdquo Nature vol 403 no 6772 pp 859ndash8662000
[10] N Ma R Thanan H Kobayashi et al ldquoNitrative DNA damageand Oct34 expression in urinary bladder cancer with Schis-tosoma haematobium infectionrdquo Biochemical and BiophysicalResearch Communications vol 414 no 2 pp 344ndash349 2011
[11] R Thanan M Murata N Ma et al ldquoNuclear localization ofCOX-2 in relation to the expression of stemness markers inurinary bladder cancerrdquo Mediators of Inflammation vol 2012Article ID 165879 8 pages 2012
[12] S Pinlaor Y Hiraku P Yongvanit et al ldquoiNOS-dependentDNA damage via NF-120581B expression in hamsters infected withOpisthorchis viverrini and its suppression by the antihelminthicdrug praziquantelrdquo International Journal of Cancer vol 119 no5 pp 1067ndash1072 2006
[13] S Pinlaor Y Hiraku NMa et al ldquoMechanism of NO-mediatedoxidative and nitrative DNA damage in hamsters infectedwithOpisthorchis viverrini a model of inflammation-mediatedcarcinogenesisrdquo Nitric Oxide vol 11 no 2 pp 175ndash183 2004
[14] S Pinlaor N Ma Y Hiraku et al ldquoRepeated infection withOpisthorchis viverrini induces accumulation of 8-nitroguanineand 8-oxo-78-dihydro-21015840-deoxyguanine in the bile duct ofhamsters via inducible nitric oxide synthaserdquo Carcinogenesisvol 25 no 8 pp 1535ndash1542 2004
[15] S Pinlaor P Yongvanit YHiraku et al ldquo8-Nitroguanine forma-tion in the liver of hamsters infectedwithOpisthorchis viverrinirdquoBiochemical and Biophysical Research Communications vol 309no 3 pp 567ndash571 2003
[16] S Pinlaor B Sripa N Ma et al ldquoNitrative and oxidative DNAdamage in intrahepatic cholangiocarcinoma patients in relationto tumor invasionrdquo World Journal of Gastroenterology vol 11no 30 pp 4644ndash4649 2005
[17] R Thanan C Pairojkul S Pinlaor et al ldquoInflammation-related DNA damage and expression of CD133 and Oct34 incholangiocarcinoma patients with poor prognosisrdquo Free RadicalBiology amp Medicine 2013
Oxidative Medicine and Cellular Longevity 7
[18] S Horiike S Kawanishi M Kaito et al ldquoAccumulation of 8-nitroguanine in the liver of patients with chronic hepatitis CrdquoJournal of Hepatology vol 43 no 3 pp 403ndash410 2005
[19] N Ali H Allam R May et al ldquoHepatitis C virus-inducedcancer stem cell-like signatures in cell culture and murinetumor xenograftsrdquo Journal of Virology vol 85 no 23 pp 12292ndash12303 2011
[20] K Machida H Tsukamoto H Mkrtchyan et al ldquoToll-likereceptor 4 mediates synergism between alcohol and HCVin hepatic oncogenesis involving stem cell marker NanogrdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 106 no 5 pp 1548ndash1553 2009
[21] Y Hiraku T Tabata N Ma M Murata X Ding and SKawanishi ldquoNitrative and oxidative DNA damage in cervicalintraepithelial neoplasia associatedwith humanpapilloma virusinfectionrdquo Cancer Science vol 98 no 7 pp 964ndash972 2007
[22] S-K Kim H-S Shim K-G Lee H-J An K-R Lee andN-H Cho ldquoGlassy cell carcinoma predominantly commits toa squamous lineage and is strongly associated with high-risktype human papillomavirus infectionrdquo International Journal ofGynecological Pathology vol 28 no 4 pp 389ndash395 2009
[23] S Regauer and O Reich ldquoCK17 and p16 expression pat-terns distinguish (atypical) immature squamous metaplasiafrom high-grade cervical intraepithelial neoplasia (CIN III)rdquoHistopathology vol 50 no 5 pp 629ndash635 2007
[24] W-K Liu Y-L Chu F Zhang et al ldquoThe relationship betweenHPV16 and expression of CD44v6 nm23H1 in esophagealsquamous cell carcinomardquo Archives of Virology vol 150 no 5pp 991ndash1001 2005
[25] D Liu P Zhou L Zhang et al ldquoHDAC1DNMT3A-containingcomplex is associated with suppression of Oct4 in cervicalcancer cellsrdquo Biochemistry vol 77 no 8 pp 934ndash940 2012
[26] N Ma M Kawanishi Y Hiraku et al ldquoReactive nitrogenspecies-dependent DNA damage in EBV-associated nasopha-ryngeal carcinoma the relation to STAT3 activation and EGFRexpressionrdquo International Journal of Cancer vol 122 no 11 pp2517ndash2525 2008
[27] Q-L Kong L-J Hu J-Y Cao et al ldquoEpstein-barr virus-encoded LMP2A induces an epithelialmdashmesenchymal transi-tion and increases the number of side population stem-likecancer cells in nasopharyngeal carcinomardquo PLoS Pathogens vol6 no 6 Article ID e1000940 2010
[28] A Dutton C B Woodman M B Chukwuma et al ldquoBmi-1 isinduced by the Epstein-Barr virus oncogene LMP1 and regulatesthe expression of viral target genes inHodgkin lymphoma cellsrdquoBlood vol 109 no 6 pp 2597ndash2603 2007
[29] N Ma Y Adachi Y Hiraku et al ldquoAccumulation of 8-nitroguanine in human gastric epithelium induced by Heli-cobacter pylori infectionrdquo Biochemical and Biophysical ResearchCommunications vol 319 no 2 pp 506ndash510 2004
[30] M Katsurahara Y Kobayashi M Iwasa et al ldquoReactivenitrogen species mediate DNA damage in helicobacter pylori-infected gastric mucosardquo Helicobacter vol 14 no 6 pp 552ndash558 2009
[31] Y Fujii K Yoshihashi H Suzuki et al ldquoCDX1 confers intestinalphenotype on gastric epithelial cells via induction of stemness-associated reprogramming factors SALL4 and KLF5rdquo Proceed-ings of the National Academy of Sciences of USA vol 109 no 50pp 20584ndash10589 2012
[32] J M Noto T Khizanishvili R Chaturvedi et al ldquoHelicobacterpylori promotes the expression of Kruppel-like factor 5
a mediator of carcinogenesis in vitro and in vivordquo PLoS Onevol 8 no 1 Article ID e54344 2013
[33] T Uehara D Ma Y Yao et al ldquoH pylori infection is associatedwith DNA damage of Lgr5-positive epithelial stem cells in thestomach of patients with gastric cancerrdquo Digestive Diseases andSciences vol 58 no 1 pp 140ndash149 2013
[34] X Ding Y Hiraku N Ma et al ldquoInducible nitric oxidesynthase-dependent DNA damage in mouse model of inflam-matory bowel diseaserdquoCancer Science vol 96 no 3 pp 157ndash1632005
[35] P Chaiyarit N Ma Y Hiraku et al ldquoNitrative and oxidativeDNA damage in oral lichen planus in relation to human oralcarcinogenesisrdquoCancer Science vol 96 no 9 pp 553ndash559 2005
[36] L Ma H Wang H Yao L Zhu W Liu and Z Zhou ldquoBmi1expression in oral lichen planus and the risk of progression tooral squamous cell carcinomardquo Annals of Diagnostic Pathologyvol 17 no 4 pp 327ndash330 2013
[37] A Bose M T Teh I L Hutchison H Wan I M Leigh andA Waseem ldquoTwo mechanisms regulate keratin K15 expressionin keratinocytes role of PKCAP-1 and FOXM1 mediatedsignallingrdquo PLoS One vol 7 no 6 Article ID e38599 2012
[38] RThanan NMa K Iijima et al ldquoProton pump inhibitors sup-press iNOS-dependent DNA damage in Barrettrsquos esophagus byincreasing Mn-SOD expressionrdquo Biochemical and BiophysicalResearch Communications vol 421 no 2 pp 280ndash285 2012
[39] J Mendelson S Song Y Li et al ldquoDysfunctional transform-ing growth factor-120573 signaling with constitutively active notchsignaling in Barrettrsquos esophageal adenocarcinomardquo Cancer vol117 no 16 pp 3691ndash3702 2011
[40] J Ahmad K Arthur P Maxwell et al ldquoRe grotenhuis et alBarrettrsquos oesophageal adenocarcinoma encompasses tumour-initiating cells that do not express common cancer stem cellmarkers J Pathol 2010 221 379ndash389rdquo Journal of Pathology vol224 no 1 pp 143ndash145 2011
[41] Y V Bobryshev A K Freeman N K Botelho D Tran AJ M Levert-Mignon and R V N Lord ldquoExpression of theputative stem cell marker Musashi-1 in Barrettrsquos esophagus andesophageal adenocarcinomardquoDiseases of the Esophagus vol 23no 7 pp 580ndash589 2010
[42] Y Hiraku S Kawanishi T Ichinose and M Murata ldquoThe roleof iNOS-mediated DNA damage in infection- and asbestos-induced carcinogenesisrdquo Annals of the New York Academy ofSciences vol 1203 pp 15ndash22 2010
[43] D Fukumura S Kashiwagi and R K Jain ldquoThe role of nitricoxide in tumour progressionrdquoNature Reviews Cancer vol 6 no7 pp 521ndash534 2006
[44] P K Lala and C Chakraborty ldquoRole of nitric oxide in carcino-genesis and tumour progressionrdquo Lancet Oncology vol 2 no 3pp 149ndash156 2001
[45] S Wang Z Liu L Wang and X Zhang ldquoNF-120581B signalingpathway inflammation and colorectal cancerrdquo Chinese Journalof Cellular andMolecular Immunology vol 6 no 5 pp 327ndash3342009
[46] V Yermilov J Rubio M Becchi M D Friesen B Pignatelliand H Ohshima ldquoFormation of 8-nitroguanine by the reactionof guanine with peroxynitrite in vitrordquo Carcinogenesis vol 16no 9 pp 2045ndash2050 1995
[47] B Halliwell ldquoOxygen and nitrogen are pro-carcinogens Dam-age to DNA by reactive oxygen chlorine and nitrogen speciesmeasurement mechanism and the effects of nutritionrdquo Muta-tion Research vol 443 no 1-2 pp 37ndash52 1999
8 Oxidative Medicine and Cellular Longevity
[48] R S Sodum and E S Fiala ldquoAnalysis of peroxynitrite reactionswith guanine xanthine and adenine nucleosides by high-pressure liquid chromatography with electrochemical detec-tion C8-nitration and -oxidationrdquo Chemical Research in Toxi-cology vol 14 no 4 pp 438ndash450 2001
[49] T Akaike S Fujii A Kato et al ldquoViral mutation acceleratedby nitric oxide production during infection in vivordquoThe FASEBJournal vol 14 no 10 pp 1447ndash1454 2000
[50] N Ma M Murata S Ohnishi R Thanan Y Hiraku and SKawanishi ldquo8-Nitroguanine a potential biomarker to evaluatethe risk of inflammation-related carcinogenesisrdquo in BiomarkerT K Kahn Ed chapter 10 pp 201ndash224 InTech Rijeka Croatia2012
[51] V Yermilov J Rubio and H Ohshima ldquoFormation of 8-nitroguanine in DNA treated with peroxynitrite in vitro and itsrapid removal from DNA by depurinationrdquo The FEBS Lettersvol 376 no 3 pp 207ndash210 1995
[52] L A Loeb and B D Preston ldquoMutagenesis by apurinicapyr-imidinic sitesrdquo Annual Review of Genetics vol 20 pp 201ndash2301986
[53] S Boiteux and M Guillet ldquoAbasic sites in DNA repair andbiological consequences in Saccharomyces cerevisiaerdquo DNARepair vol 3 no 1 pp 1ndash12 2004
[54] J E Sale A R Lehmann and R Woodgate ldquoY-family DNApolymerases and their role in tolerance of cellular DNA dam-agerdquo Nature Reviews Molecular Cell Biology vol 13 no 3 pp141ndash152 2012
[55] X Wu K Takenaka E Sonoda et al ldquoCritical roles forpolymerase 120577 in cellular tolerance to nitric oxide-induced DNAdamagerdquo Cancer Research vol 66 no 2 pp 748ndash754 2006
[56] N Suzuki M Yasui N E Geacintov V Shafirovich and SShibutani ldquoMiscoding events during DNA synthesis past thenitration-damaged base 8-nitroguaninerdquo Biochemistry vol 44no 25 pp 9238ndash9245 2005
[57] M Y Kim M Dong P C Dedon and G N Wogan ldquoEffects ofperoxynitrite dose and dose rate onDNAdamage andmutationin the supF shuttle vectorrdquo Chemical Research in Toxicology vol18 no 1 pp 76ndash86 2005
[58] IARC ldquoOpisthorchis viverrini and Clonorchis sinensisrdquo in AReview of Human CarcInogens Biological Agents vol 100B ofIARC Monographs on the Evaluation of Carcinogenic Risks toHumans pp 347ndash376 IARC Press Lyon France 2012
[59] J P EiserichM Hristova C E Cross et al ldquoFormation of nitricoxide-derived inflammatory oxidants by myeloperoxidase inneutrophilsrdquo Nature vol 391 no 6665 pp 393ndash397 1998
[60] J P Gaut J Byun H D Tran et al ldquoMyeloperoxidase producesnitrating oxidants in vivordquo Journal of Clinical Investigation vol109 no 10 pp 1311ndash1319 2002
[61] S Tanaka N Choe D R Hemenway S Zhu S Matalon andE Kagan ldquoAsbestos inhalation induces reactive nitrogen speciesand nitrotyrosine formation in the lungs and pleura of the ratrdquoJournal of Clinical Investigation vol 102 no 2 pp 445ndash4541998
[62] A Van Der Vliet J P Eiserich M K Shigenaga and C ECross ldquoReactive nitrogen species and tyrosine nitration in therespiratory tract epiphenomena or a pathobiologic mechanismof diseaserdquo American Journal of Respiratory and Critical CareMedicine vol 160 no 1 pp 1ndash9 1999
[63] A Haegens A Van Der Vliet K J Butnor et al ldquoAsbestos-induced lung inflammation and epithelial cell proliferation arealtered in myeloperoxidase-null micerdquoCancer Research vol 65no 21 pp 9670ndash9677 2005
[64] N Suzuki M Yasui N E Geacintov V Shafirovich and SShibutani ldquoMiscoding events during DNA synthesis past thenitration-damaged base 8-nitroguaninerdquo Biochemistry vol 44no 25 pp 9238ndash9245 2005
[65] S Shibutani M Takeshita and A P Grollman ldquoInsertionof specific bases during DNA synthesis past the oxidation-damaged base 8-oxodGrdquoNature vol 349 no 6308 pp 431ndash4341991
[66] J L Bos ldquoThe ras gene family and human carcinogenesisrdquoMutation Research vol 195 no 3 pp 255ndash271 1988
[67] S P Hussain L J Hofseth and C C Harris ldquoRadical causes ofcancerrdquoNature Reviews Cancer vol 3 no 4 pp 276ndash285 2003
[68] T Takahashi M M Nau I Chiba et al ldquop53 a frequent targetfor genetic abnormalities in lung cancerrdquo Science vol 246 no4929 pp 491ndash494 1989
[69] S Ohnishi H Saito N Suzuki et al ldquoNitrative and oxidativeDNA damage caused by K-ras mutation in micerdquo Biochemicaland Biophysical Research Communications vol 413 no 2 pp236ndash240 2011
[70] M Shipitsin and K Polyak ldquoThe cancer stem cell hypothesisin search of definitions markers and relevancerdquo LaboratoryInvestigation vol 88 no 5 pp 459ndash463 2008
[71] S Sell ldquoInfection stem cells and cancer signalsrdquo Current Phar-maceutical Biotechnology vol 12 no 2 pp 182ndash188 2011
[72] S Reuter S C Gupta M M Chaturvedi and B B AggarwalldquoOxidative stress inflammation and cancer how are theylinkedrdquo Free Radical Biology and Medicine vol 49 no 11 pp1603ndash1616 2010
[73] Y Jing Z Han Y Liu et al ldquoMesenchymal stem cellsin inflammation microenvironment accelerates hepatocellu-lar carcinoma metastasis by inducing epithelial-mesenchymaltransitionrdquo PLoS One vol 7 no 8 Article ID e43272 2012
[74] N J Maitland and A T Collins ldquoInflammation as the primaryaetiological agent of human prostate cancer a stem cell con-nectionrdquo Journal of Cellular Biochemistry vol 105 no 4 pp931ndash939 2008
[75] Z A Shaker M A Kaddah S B Hanallah and M I El-Khodary ldquoProduction of monoclonal antibodies against targetschistosomal antigen secreted in the urine of schistosomamansoni-infected patientsrdquo International Journal for Parasitol-ogy vol 28 no 12 pp 1893ndash1901 1998
[76] IARC ldquoSchistosoma haematobiumrdquo in A Review of HumanCarcInogens Biological Agents vol 100B of IARC Monographson the Evaluation of Carcinogenic Risks to Humans pp 371ndash384IARC Press Lyon France 2012
[77] E I Salim K Morimura A Menesi M El-Lity S Fukushimaand HWanibuchi ldquoElevated oxidative stress and DNA damageand repair levels in urinary bladder carcinomas associated withschistosomiasisrdquo International Journal of Cancer vol 123 no 3pp 601ndash608 2008
[78] A N Wamachi J S Mayadev P L Mungai et al ldquoIncreasedratio of tumor necrosis factor-120572 to interleukin-10 productionis associated with Schistosoma haematobium-induced urinary-tract morbidityrdquo Journal of Infectious Diseases vol 190 no 11pp 2020ndash2030 2004
[79] L H Looijenga H Stoop H P De Leeuw et al ldquoPOU5F1(OCT34) identifies cells with pluripotent potential in humangerm cell tumorsrdquo Cancer Research vol 63 no 9 pp 2244ndash2250 2003
[80] Y-C Chen H-S Hsu Y-W Chen et al ldquoOct-4 expressionmaintained cancer stem-like properties in lung cancer-derived
Oxidative Medicine and Cellular Longevity 9
CD133-positive cellsrdquo PLoS One vol 3 no 7 Article ID e26372008
[81] D Ponti A Costa N Zaffaroni et al ldquoIsolation and in vitropropagation of tumorigenic breast cancer cells with stempro-genitor cell propertiesrdquo Cancer Research vol 65 no 13 pp5506ndash5511 2005
[82] Y Matsumura and D Tarin ldquoSignificance of CD44 geneproducts for cancer diagnosis and disease evaluationrdquo Lancetvol 340 no 8827 pp 1053ndash1058 1992
[83] S Saito H Okabe M Watanabe et al ldquoCD44v6 expressionis related to mesenchymal phenotype and poor prognosis inpatients with colorectal cancerrdquo Oncology Reports vol 29 no4 pp 1570ndash1578 2013
[84] E M Peek D R Li H Zhang et al ldquoStromal modulation ofbladder cancer-initiating cells in a subcutaneous tumor modelrdquoAmerican Journal of Cancer Research vol 2 no 6 pp 745ndash7512012
[85] J Kuncova M Urban and V Mandys ldquoExpression of CD44sand CD44v6 in transitional cell carcinomas of the urinarybladder comparison with tumour grade proliferative activityand p53 immunoreactivity of tumour cellsrdquoAPMIS vol 115 no11 pp 1194ndash1205 2007
[86] M Sugiyama A Woodman T Sugino et al ldquoNon-invasivedetection of bladder cancer by identification of abnormal CD44proteins in exfoliated cancer cells in urinerdquo Journal of ClinicalMolecular Pathology vol 48 no 3 pp M142ndashM147 1995
[87] Y M Yang and J W Chang ldquoBladder cancer initiating cells(BCICs) are among EMAminusCD44v6+ subset novel methods forisolating undetermined cancer stem (initiating) cellsrdquo CancerInvestigation vol 26 no 7 pp 725ndash733 2008
[88] R Thanan S Oikawa P Yongvanit et al ldquoInflammation-induced protein carbonylation contributes to poor prognosisfor cholangiocarcinomardquo Free Radical Biology and Medicinevol 52 no 8 pp 1465ndash1472 2012
Figure 2 Postulated mechanism for generating cancer stem cells by inflammation
4 DNA Damage and Mutant Stem CellsInduced by Opisthorchis viverrini Infection
Chronic infection with the liver fluke OV is associatedwith cholangiocarcinomas [58] Infection with this para-site is repeatedly caused by eating raw fish containing theinfective stage of the fluke We have demonstrated that 8-nitroguanine is formed in relation to inflammation-relatedcarcinogenesis using an animal model [12ndash15] 8-OxodGand 8-nitroguanine were formed in inflammatory cells andepithelium of bile ducts and their formation increased in amanner dependent on infection timesThe anthelmintic drugpraziquantel dramatically diminished these DNA lesions andiNOS expression in OV-infected hamsters Thus repeatedOV-infection can induce the iNOS expression in bile ductsand subsequently cause nitrative and oxidative damage tonucleic acids which may participate in cholangiocarcinoma
In our study with patients the formation of 8-oxodGand 8-nitroguanine occurred to a much greater extent incancerous tissue than in noncancerous tissue in intrahepaticcholangiocarcinoma patients indicating that these DNAlesions contribute to tumor progression [16] Our proteomicstudy showed that carbonylation of serotransferrin and heatshock protein 70 kDa protein 1 (HSP701) is significantlyassociated with poor prognoses [88] Carbonylation of pro-tein is an irreversible modification induced by oxidativestress We have proposed that carbonylations of serotrans-ferrin and HSP701 may induce oxidative stress by iron-accumulation and dysfunction of antioxidative propertyleading to increased oxidative DNA damage and progressionof cholangiocarcinoma
Recently we observed high expression and co-locali-zation of hepatocyte marker and cholangiocyte marker inOV-associated cholangiocarcinoma patients suggesting the
6 Oxidative Medicine and Cellular Longevity
involvement of stem cells in cholangiocarcinoma develop-ment [17] Cholangiocarcinoma tissues with positive stem-ness markers (CD133 or Oct34) showed significantly lowerexpression of antioxidant enzyme Mn-SOD and significantlyhigher levels of 8-oxodG 8-nitroguanine and DNA damageresponse protein 120574-H2AX Moreover CD133- and Oct34-positive cholangiocarcinoma patients had significant associa-tionswith tumor histology types tumor stage and poor prog-noses These findings suggest that CD133 and Oct34 in cho-langiocarcinoma are highly associated with formation ofDNA lesions whichmay be involved in genetic instability andlead to tumor development with aggressive clinical featuresIn our study proliferating cell nuclear antigen (PCNA)accumulated in the epithelium of bile ducts of hamsters afterrepeated OV infection supporting the hypothesis that cellproliferation is promoted by inflammation-mediated DNAdamage [14] Inflammation by OV infection may increasethe number of mutant stem cell in which oxidative stressessuch as carbonylation of proteins and oxidativeDNAdamageand cell proliferation are promoted leading to progression ofcholangiocarcinoma
5 Conclusions
Nitrative and oxidative DNA lesions with mutagenic proper-ties are formed in various types of inflammation-related can-cer tissuesWehave proposed amechanism for the generationof cancer stem cells by inflammation in Figure 2 Chronicinflammation by infectious agents inflammatory diseasesand other factors causes various types of damage to nucleicacids proteins tissue and so on via ROSRNS generationTissue injury under chronic inflammation may activate pro-genitorstem cells for regeneration In these cells ROSRNSfrom inflammation can cause multiple mutations whichmaygenerate mutant stem cells and cancer stem cells leadingto carcinogenesis Indeed 8-nitroguanine was formed instemness marker-positive cells in parasite-associated cancertissues The mechanism for generation of cancer stem cellswill be explained by our ongoing studies on the formation of8-nitroguanine in stem-like cells of target tissues associatedwith other inflammation-related cancers
Conflict of Interests
The authors declare that they have no conflict of interests
Acknowledgment
This work was supported by a grant-in-aid from theMinistryof Education Culture Sports Science and Technology ofJapan
References
[1] L M Coussens and Z Werb ldquoInflammation and cancerrdquoNature vol 420 no 6917 pp 860ndash867 2002
[2] S Kawanishi and Y Hiraku ldquoOxidative and nitrative DNAdamage as biomarker for carcinogenesis with special reference
to inflammationrdquo Antioxidants and Redox Signaling vol 8 no5-6 pp 1047ndash1058 2006
[3] M Murata R Thanan N Ma and S Kawanishi ldquoRole ofnitrative and oxidative DNA damage in inflammation-relatedcarcinogenesisrdquo Journal of Biomedicine and Biotechnology vol2012 Article ID 623019 11 pages 2012
[4] IARC ldquoChronic infectionsrdquo in World Cancer Report B WStewart and P Kleihues Eds pp 128ndash135 IARC Press LyonFrance 2008
[5] S P Hussain and C C Harris ldquoInflammation and canceran ancient link with novel potentialsrdquo International Journal ofCancer vol 121 no 11 pp 2373ndash2380 2007
[6] A J Schetter N H Heegaard and C C Harris ldquoInflammationand cancer interweaving microRNA free radical cytokine andp53 pathwaysrdquo Carcinogenesis vol 31 no 1 Article ID bgp272pp 37ndash49 2010
[7] H Ohshima M Tatemichi and T Sawa ldquoChemical basis ofinflammation-induced carcinogenesisrdquo Archives of Biochem-istry and Biophysics vol 417 no 1 pp 3ndash11 2003
[8] S Kawanishi Y Hiraku and S Oikawa ldquoMechanism ofguanine-specific DNA damage by oxidative stress and its rolein carcinogenesis and agingrdquoMutation Research vol 488 no 1pp 65ndash76 2001
[9] S D Bruner D P G Norman and G L Verdine ldquoStructuralbasis for recognition and repair of the endogenous mutagen 8-oxoguanine in DNArdquo Nature vol 403 no 6772 pp 859ndash8662000
[10] N Ma R Thanan H Kobayashi et al ldquoNitrative DNA damageand Oct34 expression in urinary bladder cancer with Schis-tosoma haematobium infectionrdquo Biochemical and BiophysicalResearch Communications vol 414 no 2 pp 344ndash349 2011
[11] R Thanan M Murata N Ma et al ldquoNuclear localization ofCOX-2 in relation to the expression of stemness markers inurinary bladder cancerrdquo Mediators of Inflammation vol 2012Article ID 165879 8 pages 2012
[12] S Pinlaor Y Hiraku P Yongvanit et al ldquoiNOS-dependentDNA damage via NF-120581B expression in hamsters infected withOpisthorchis viverrini and its suppression by the antihelminthicdrug praziquantelrdquo International Journal of Cancer vol 119 no5 pp 1067ndash1072 2006
[13] S Pinlaor Y Hiraku NMa et al ldquoMechanism of NO-mediatedoxidative and nitrative DNA damage in hamsters infectedwithOpisthorchis viverrini a model of inflammation-mediatedcarcinogenesisrdquo Nitric Oxide vol 11 no 2 pp 175ndash183 2004
[14] S Pinlaor N Ma Y Hiraku et al ldquoRepeated infection withOpisthorchis viverrini induces accumulation of 8-nitroguanineand 8-oxo-78-dihydro-21015840-deoxyguanine in the bile duct ofhamsters via inducible nitric oxide synthaserdquo Carcinogenesisvol 25 no 8 pp 1535ndash1542 2004
[15] S Pinlaor P Yongvanit YHiraku et al ldquo8-Nitroguanine forma-tion in the liver of hamsters infectedwithOpisthorchis viverrinirdquoBiochemical and Biophysical Research Communications vol 309no 3 pp 567ndash571 2003
[16] S Pinlaor B Sripa N Ma et al ldquoNitrative and oxidative DNAdamage in intrahepatic cholangiocarcinoma patients in relationto tumor invasionrdquo World Journal of Gastroenterology vol 11no 30 pp 4644ndash4649 2005
[17] R Thanan C Pairojkul S Pinlaor et al ldquoInflammation-related DNA damage and expression of CD133 and Oct34 incholangiocarcinoma patients with poor prognosisrdquo Free RadicalBiology amp Medicine 2013
Oxidative Medicine and Cellular Longevity 7
[18] S Horiike S Kawanishi M Kaito et al ldquoAccumulation of 8-nitroguanine in the liver of patients with chronic hepatitis CrdquoJournal of Hepatology vol 43 no 3 pp 403ndash410 2005
[19] N Ali H Allam R May et al ldquoHepatitis C virus-inducedcancer stem cell-like signatures in cell culture and murinetumor xenograftsrdquo Journal of Virology vol 85 no 23 pp 12292ndash12303 2011
[20] K Machida H Tsukamoto H Mkrtchyan et al ldquoToll-likereceptor 4 mediates synergism between alcohol and HCVin hepatic oncogenesis involving stem cell marker NanogrdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 106 no 5 pp 1548ndash1553 2009
[21] Y Hiraku T Tabata N Ma M Murata X Ding and SKawanishi ldquoNitrative and oxidative DNA damage in cervicalintraepithelial neoplasia associatedwith humanpapilloma virusinfectionrdquo Cancer Science vol 98 no 7 pp 964ndash972 2007
[22] S-K Kim H-S Shim K-G Lee H-J An K-R Lee andN-H Cho ldquoGlassy cell carcinoma predominantly commits toa squamous lineage and is strongly associated with high-risktype human papillomavirus infectionrdquo International Journal ofGynecological Pathology vol 28 no 4 pp 389ndash395 2009
[23] S Regauer and O Reich ldquoCK17 and p16 expression pat-terns distinguish (atypical) immature squamous metaplasiafrom high-grade cervical intraepithelial neoplasia (CIN III)rdquoHistopathology vol 50 no 5 pp 629ndash635 2007
[24] W-K Liu Y-L Chu F Zhang et al ldquoThe relationship betweenHPV16 and expression of CD44v6 nm23H1 in esophagealsquamous cell carcinomardquo Archives of Virology vol 150 no 5pp 991ndash1001 2005
[25] D Liu P Zhou L Zhang et al ldquoHDAC1DNMT3A-containingcomplex is associated with suppression of Oct4 in cervicalcancer cellsrdquo Biochemistry vol 77 no 8 pp 934ndash940 2012
[26] N Ma M Kawanishi Y Hiraku et al ldquoReactive nitrogenspecies-dependent DNA damage in EBV-associated nasopha-ryngeal carcinoma the relation to STAT3 activation and EGFRexpressionrdquo International Journal of Cancer vol 122 no 11 pp2517ndash2525 2008
[27] Q-L Kong L-J Hu J-Y Cao et al ldquoEpstein-barr virus-encoded LMP2A induces an epithelialmdashmesenchymal transi-tion and increases the number of side population stem-likecancer cells in nasopharyngeal carcinomardquo PLoS Pathogens vol6 no 6 Article ID e1000940 2010
[28] A Dutton C B Woodman M B Chukwuma et al ldquoBmi-1 isinduced by the Epstein-Barr virus oncogene LMP1 and regulatesthe expression of viral target genes inHodgkin lymphoma cellsrdquoBlood vol 109 no 6 pp 2597ndash2603 2007
[29] N Ma Y Adachi Y Hiraku et al ldquoAccumulation of 8-nitroguanine in human gastric epithelium induced by Heli-cobacter pylori infectionrdquo Biochemical and Biophysical ResearchCommunications vol 319 no 2 pp 506ndash510 2004
[30] M Katsurahara Y Kobayashi M Iwasa et al ldquoReactivenitrogen species mediate DNA damage in helicobacter pylori-infected gastric mucosardquo Helicobacter vol 14 no 6 pp 552ndash558 2009
[31] Y Fujii K Yoshihashi H Suzuki et al ldquoCDX1 confers intestinalphenotype on gastric epithelial cells via induction of stemness-associated reprogramming factors SALL4 and KLF5rdquo Proceed-ings of the National Academy of Sciences of USA vol 109 no 50pp 20584ndash10589 2012
[32] J M Noto T Khizanishvili R Chaturvedi et al ldquoHelicobacterpylori promotes the expression of Kruppel-like factor 5
a mediator of carcinogenesis in vitro and in vivordquo PLoS Onevol 8 no 1 Article ID e54344 2013
[33] T Uehara D Ma Y Yao et al ldquoH pylori infection is associatedwith DNA damage of Lgr5-positive epithelial stem cells in thestomach of patients with gastric cancerrdquo Digestive Diseases andSciences vol 58 no 1 pp 140ndash149 2013
[34] X Ding Y Hiraku N Ma et al ldquoInducible nitric oxidesynthase-dependent DNA damage in mouse model of inflam-matory bowel diseaserdquoCancer Science vol 96 no 3 pp 157ndash1632005
[35] P Chaiyarit N Ma Y Hiraku et al ldquoNitrative and oxidativeDNA damage in oral lichen planus in relation to human oralcarcinogenesisrdquoCancer Science vol 96 no 9 pp 553ndash559 2005
[36] L Ma H Wang H Yao L Zhu W Liu and Z Zhou ldquoBmi1expression in oral lichen planus and the risk of progression tooral squamous cell carcinomardquo Annals of Diagnostic Pathologyvol 17 no 4 pp 327ndash330 2013
[37] A Bose M T Teh I L Hutchison H Wan I M Leigh andA Waseem ldquoTwo mechanisms regulate keratin K15 expressionin keratinocytes role of PKCAP-1 and FOXM1 mediatedsignallingrdquo PLoS One vol 7 no 6 Article ID e38599 2012
[38] RThanan NMa K Iijima et al ldquoProton pump inhibitors sup-press iNOS-dependent DNA damage in Barrettrsquos esophagus byincreasing Mn-SOD expressionrdquo Biochemical and BiophysicalResearch Communications vol 421 no 2 pp 280ndash285 2012
[39] J Mendelson S Song Y Li et al ldquoDysfunctional transform-ing growth factor-120573 signaling with constitutively active notchsignaling in Barrettrsquos esophageal adenocarcinomardquo Cancer vol117 no 16 pp 3691ndash3702 2011
[40] J Ahmad K Arthur P Maxwell et al ldquoRe grotenhuis et alBarrettrsquos oesophageal adenocarcinoma encompasses tumour-initiating cells that do not express common cancer stem cellmarkers J Pathol 2010 221 379ndash389rdquo Journal of Pathology vol224 no 1 pp 143ndash145 2011
[41] Y V Bobryshev A K Freeman N K Botelho D Tran AJ M Levert-Mignon and R V N Lord ldquoExpression of theputative stem cell marker Musashi-1 in Barrettrsquos esophagus andesophageal adenocarcinomardquoDiseases of the Esophagus vol 23no 7 pp 580ndash589 2010
[42] Y Hiraku S Kawanishi T Ichinose and M Murata ldquoThe roleof iNOS-mediated DNA damage in infection- and asbestos-induced carcinogenesisrdquo Annals of the New York Academy ofSciences vol 1203 pp 15ndash22 2010
[43] D Fukumura S Kashiwagi and R K Jain ldquoThe role of nitricoxide in tumour progressionrdquoNature Reviews Cancer vol 6 no7 pp 521ndash534 2006
[44] P K Lala and C Chakraborty ldquoRole of nitric oxide in carcino-genesis and tumour progressionrdquo Lancet Oncology vol 2 no 3pp 149ndash156 2001
[45] S Wang Z Liu L Wang and X Zhang ldquoNF-120581B signalingpathway inflammation and colorectal cancerrdquo Chinese Journalof Cellular andMolecular Immunology vol 6 no 5 pp 327ndash3342009
[46] V Yermilov J Rubio M Becchi M D Friesen B Pignatelliand H Ohshima ldquoFormation of 8-nitroguanine by the reactionof guanine with peroxynitrite in vitrordquo Carcinogenesis vol 16no 9 pp 2045ndash2050 1995
[47] B Halliwell ldquoOxygen and nitrogen are pro-carcinogens Dam-age to DNA by reactive oxygen chlorine and nitrogen speciesmeasurement mechanism and the effects of nutritionrdquo Muta-tion Research vol 443 no 1-2 pp 37ndash52 1999
8 Oxidative Medicine and Cellular Longevity
[48] R S Sodum and E S Fiala ldquoAnalysis of peroxynitrite reactionswith guanine xanthine and adenine nucleosides by high-pressure liquid chromatography with electrochemical detec-tion C8-nitration and -oxidationrdquo Chemical Research in Toxi-cology vol 14 no 4 pp 438ndash450 2001
[49] T Akaike S Fujii A Kato et al ldquoViral mutation acceleratedby nitric oxide production during infection in vivordquoThe FASEBJournal vol 14 no 10 pp 1447ndash1454 2000
[50] N Ma M Murata S Ohnishi R Thanan Y Hiraku and SKawanishi ldquo8-Nitroguanine a potential biomarker to evaluatethe risk of inflammation-related carcinogenesisrdquo in BiomarkerT K Kahn Ed chapter 10 pp 201ndash224 InTech Rijeka Croatia2012
[51] V Yermilov J Rubio and H Ohshima ldquoFormation of 8-nitroguanine in DNA treated with peroxynitrite in vitro and itsrapid removal from DNA by depurinationrdquo The FEBS Lettersvol 376 no 3 pp 207ndash210 1995
[52] L A Loeb and B D Preston ldquoMutagenesis by apurinicapyr-imidinic sitesrdquo Annual Review of Genetics vol 20 pp 201ndash2301986
[53] S Boiteux and M Guillet ldquoAbasic sites in DNA repair andbiological consequences in Saccharomyces cerevisiaerdquo DNARepair vol 3 no 1 pp 1ndash12 2004
[54] J E Sale A R Lehmann and R Woodgate ldquoY-family DNApolymerases and their role in tolerance of cellular DNA dam-agerdquo Nature Reviews Molecular Cell Biology vol 13 no 3 pp141ndash152 2012
[55] X Wu K Takenaka E Sonoda et al ldquoCritical roles forpolymerase 120577 in cellular tolerance to nitric oxide-induced DNAdamagerdquo Cancer Research vol 66 no 2 pp 748ndash754 2006
[56] N Suzuki M Yasui N E Geacintov V Shafirovich and SShibutani ldquoMiscoding events during DNA synthesis past thenitration-damaged base 8-nitroguaninerdquo Biochemistry vol 44no 25 pp 9238ndash9245 2005
[57] M Y Kim M Dong P C Dedon and G N Wogan ldquoEffects ofperoxynitrite dose and dose rate onDNAdamage andmutationin the supF shuttle vectorrdquo Chemical Research in Toxicology vol18 no 1 pp 76ndash86 2005
[58] IARC ldquoOpisthorchis viverrini and Clonorchis sinensisrdquo in AReview of Human CarcInogens Biological Agents vol 100B ofIARC Monographs on the Evaluation of Carcinogenic Risks toHumans pp 347ndash376 IARC Press Lyon France 2012
[59] J P EiserichM Hristova C E Cross et al ldquoFormation of nitricoxide-derived inflammatory oxidants by myeloperoxidase inneutrophilsrdquo Nature vol 391 no 6665 pp 393ndash397 1998
[60] J P Gaut J Byun H D Tran et al ldquoMyeloperoxidase producesnitrating oxidants in vivordquo Journal of Clinical Investigation vol109 no 10 pp 1311ndash1319 2002
[61] S Tanaka N Choe D R Hemenway S Zhu S Matalon andE Kagan ldquoAsbestos inhalation induces reactive nitrogen speciesand nitrotyrosine formation in the lungs and pleura of the ratrdquoJournal of Clinical Investigation vol 102 no 2 pp 445ndash4541998
[62] A Van Der Vliet J P Eiserich M K Shigenaga and C ECross ldquoReactive nitrogen species and tyrosine nitration in therespiratory tract epiphenomena or a pathobiologic mechanismof diseaserdquo American Journal of Respiratory and Critical CareMedicine vol 160 no 1 pp 1ndash9 1999
[63] A Haegens A Van Der Vliet K J Butnor et al ldquoAsbestos-induced lung inflammation and epithelial cell proliferation arealtered in myeloperoxidase-null micerdquoCancer Research vol 65no 21 pp 9670ndash9677 2005
[64] N Suzuki M Yasui N E Geacintov V Shafirovich and SShibutani ldquoMiscoding events during DNA synthesis past thenitration-damaged base 8-nitroguaninerdquo Biochemistry vol 44no 25 pp 9238ndash9245 2005
[65] S Shibutani M Takeshita and A P Grollman ldquoInsertionof specific bases during DNA synthesis past the oxidation-damaged base 8-oxodGrdquoNature vol 349 no 6308 pp 431ndash4341991
[66] J L Bos ldquoThe ras gene family and human carcinogenesisrdquoMutation Research vol 195 no 3 pp 255ndash271 1988
[67] S P Hussain L J Hofseth and C C Harris ldquoRadical causes ofcancerrdquoNature Reviews Cancer vol 3 no 4 pp 276ndash285 2003
[68] T Takahashi M M Nau I Chiba et al ldquop53 a frequent targetfor genetic abnormalities in lung cancerrdquo Science vol 246 no4929 pp 491ndash494 1989
[69] S Ohnishi H Saito N Suzuki et al ldquoNitrative and oxidativeDNA damage caused by K-ras mutation in micerdquo Biochemicaland Biophysical Research Communications vol 413 no 2 pp236ndash240 2011
[70] M Shipitsin and K Polyak ldquoThe cancer stem cell hypothesisin search of definitions markers and relevancerdquo LaboratoryInvestigation vol 88 no 5 pp 459ndash463 2008
[71] S Sell ldquoInfection stem cells and cancer signalsrdquo Current Phar-maceutical Biotechnology vol 12 no 2 pp 182ndash188 2011
[72] S Reuter S C Gupta M M Chaturvedi and B B AggarwalldquoOxidative stress inflammation and cancer how are theylinkedrdquo Free Radical Biology and Medicine vol 49 no 11 pp1603ndash1616 2010
[73] Y Jing Z Han Y Liu et al ldquoMesenchymal stem cellsin inflammation microenvironment accelerates hepatocellu-lar carcinoma metastasis by inducing epithelial-mesenchymaltransitionrdquo PLoS One vol 7 no 8 Article ID e43272 2012
[74] N J Maitland and A T Collins ldquoInflammation as the primaryaetiological agent of human prostate cancer a stem cell con-nectionrdquo Journal of Cellular Biochemistry vol 105 no 4 pp931ndash939 2008
[75] Z A Shaker M A Kaddah S B Hanallah and M I El-Khodary ldquoProduction of monoclonal antibodies against targetschistosomal antigen secreted in the urine of schistosomamansoni-infected patientsrdquo International Journal for Parasitol-ogy vol 28 no 12 pp 1893ndash1901 1998
[76] IARC ldquoSchistosoma haematobiumrdquo in A Review of HumanCarcInogens Biological Agents vol 100B of IARC Monographson the Evaluation of Carcinogenic Risks to Humans pp 371ndash384IARC Press Lyon France 2012
[77] E I Salim K Morimura A Menesi M El-Lity S Fukushimaand HWanibuchi ldquoElevated oxidative stress and DNA damageand repair levels in urinary bladder carcinomas associated withschistosomiasisrdquo International Journal of Cancer vol 123 no 3pp 601ndash608 2008
[78] A N Wamachi J S Mayadev P L Mungai et al ldquoIncreasedratio of tumor necrosis factor-120572 to interleukin-10 productionis associated with Schistosoma haematobium-induced urinary-tract morbidityrdquo Journal of Infectious Diseases vol 190 no 11pp 2020ndash2030 2004
[79] L H Looijenga H Stoop H P De Leeuw et al ldquoPOU5F1(OCT34) identifies cells with pluripotent potential in humangerm cell tumorsrdquo Cancer Research vol 63 no 9 pp 2244ndash2250 2003
[80] Y-C Chen H-S Hsu Y-W Chen et al ldquoOct-4 expressionmaintained cancer stem-like properties in lung cancer-derived
Oxidative Medicine and Cellular Longevity 9
CD133-positive cellsrdquo PLoS One vol 3 no 7 Article ID e26372008
[81] D Ponti A Costa N Zaffaroni et al ldquoIsolation and in vitropropagation of tumorigenic breast cancer cells with stempro-genitor cell propertiesrdquo Cancer Research vol 65 no 13 pp5506ndash5511 2005
[82] Y Matsumura and D Tarin ldquoSignificance of CD44 geneproducts for cancer diagnosis and disease evaluationrdquo Lancetvol 340 no 8827 pp 1053ndash1058 1992
[83] S Saito H Okabe M Watanabe et al ldquoCD44v6 expressionis related to mesenchymal phenotype and poor prognosis inpatients with colorectal cancerrdquo Oncology Reports vol 29 no4 pp 1570ndash1578 2013
[84] E M Peek D R Li H Zhang et al ldquoStromal modulation ofbladder cancer-initiating cells in a subcutaneous tumor modelrdquoAmerican Journal of Cancer Research vol 2 no 6 pp 745ndash7512012
[85] J Kuncova M Urban and V Mandys ldquoExpression of CD44sand CD44v6 in transitional cell carcinomas of the urinarybladder comparison with tumour grade proliferative activityand p53 immunoreactivity of tumour cellsrdquoAPMIS vol 115 no11 pp 1194ndash1205 2007
[86] M Sugiyama A Woodman T Sugino et al ldquoNon-invasivedetection of bladder cancer by identification of abnormal CD44proteins in exfoliated cancer cells in urinerdquo Journal of ClinicalMolecular Pathology vol 48 no 3 pp M142ndashM147 1995
[87] Y M Yang and J W Chang ldquoBladder cancer initiating cells(BCICs) are among EMAminusCD44v6+ subset novel methods forisolating undetermined cancer stem (initiating) cellsrdquo CancerInvestigation vol 26 no 7 pp 725ndash733 2008
[88] R Thanan S Oikawa P Yongvanit et al ldquoInflammation-induced protein carbonylation contributes to poor prognosisfor cholangiocarcinomardquo Free Radical Biology and Medicinevol 52 no 8 pp 1465ndash1472 2012
6 Oxidative Medicine and Cellular Longevity
involvement of stem cells in cholangiocarcinoma develop-ment [17] Cholangiocarcinoma tissues with positive stem-ness markers (CD133 or Oct34) showed significantly lowerexpression of antioxidant enzyme Mn-SOD and significantlyhigher levels of 8-oxodG 8-nitroguanine and DNA damageresponse protein 120574-H2AX Moreover CD133- and Oct34-positive cholangiocarcinoma patients had significant associa-tionswith tumor histology types tumor stage and poor prog-noses These findings suggest that CD133 and Oct34 in cho-langiocarcinoma are highly associated with formation ofDNA lesions whichmay be involved in genetic instability andlead to tumor development with aggressive clinical featuresIn our study proliferating cell nuclear antigen (PCNA)accumulated in the epithelium of bile ducts of hamsters afterrepeated OV infection supporting the hypothesis that cellproliferation is promoted by inflammation-mediated DNAdamage [14] Inflammation by OV infection may increasethe number of mutant stem cell in which oxidative stressessuch as carbonylation of proteins and oxidativeDNAdamageand cell proliferation are promoted leading to progression ofcholangiocarcinoma
5 Conclusions
Nitrative and oxidative DNA lesions with mutagenic proper-ties are formed in various types of inflammation-related can-cer tissuesWehave proposed amechanism for the generationof cancer stem cells by inflammation in Figure 2 Chronicinflammation by infectious agents inflammatory diseasesand other factors causes various types of damage to nucleicacids proteins tissue and so on via ROSRNS generationTissue injury under chronic inflammation may activate pro-genitorstem cells for regeneration In these cells ROSRNSfrom inflammation can cause multiple mutations whichmaygenerate mutant stem cells and cancer stem cells leadingto carcinogenesis Indeed 8-nitroguanine was formed instemness marker-positive cells in parasite-associated cancertissues The mechanism for generation of cancer stem cellswill be explained by our ongoing studies on the formation of8-nitroguanine in stem-like cells of target tissues associatedwith other inflammation-related cancers
Conflict of Interests
The authors declare that they have no conflict of interests
Acknowledgment
This work was supported by a grant-in-aid from theMinistryof Education Culture Sports Science and Technology ofJapan
References
[1] L M Coussens and Z Werb ldquoInflammation and cancerrdquoNature vol 420 no 6917 pp 860ndash867 2002
[2] S Kawanishi and Y Hiraku ldquoOxidative and nitrative DNAdamage as biomarker for carcinogenesis with special reference
to inflammationrdquo Antioxidants and Redox Signaling vol 8 no5-6 pp 1047ndash1058 2006
[3] M Murata R Thanan N Ma and S Kawanishi ldquoRole ofnitrative and oxidative DNA damage in inflammation-relatedcarcinogenesisrdquo Journal of Biomedicine and Biotechnology vol2012 Article ID 623019 11 pages 2012
[4] IARC ldquoChronic infectionsrdquo in World Cancer Report B WStewart and P Kleihues Eds pp 128ndash135 IARC Press LyonFrance 2008
[5] S P Hussain and C C Harris ldquoInflammation and canceran ancient link with novel potentialsrdquo International Journal ofCancer vol 121 no 11 pp 2373ndash2380 2007
[6] A J Schetter N H Heegaard and C C Harris ldquoInflammationand cancer interweaving microRNA free radical cytokine andp53 pathwaysrdquo Carcinogenesis vol 31 no 1 Article ID bgp272pp 37ndash49 2010
[7] H Ohshima M Tatemichi and T Sawa ldquoChemical basis ofinflammation-induced carcinogenesisrdquo Archives of Biochem-istry and Biophysics vol 417 no 1 pp 3ndash11 2003
[8] S Kawanishi Y Hiraku and S Oikawa ldquoMechanism ofguanine-specific DNA damage by oxidative stress and its rolein carcinogenesis and agingrdquoMutation Research vol 488 no 1pp 65ndash76 2001
[9] S D Bruner D P G Norman and G L Verdine ldquoStructuralbasis for recognition and repair of the endogenous mutagen 8-oxoguanine in DNArdquo Nature vol 403 no 6772 pp 859ndash8662000
[10] N Ma R Thanan H Kobayashi et al ldquoNitrative DNA damageand Oct34 expression in urinary bladder cancer with Schis-tosoma haematobium infectionrdquo Biochemical and BiophysicalResearch Communications vol 414 no 2 pp 344ndash349 2011
[11] R Thanan M Murata N Ma et al ldquoNuclear localization ofCOX-2 in relation to the expression of stemness markers inurinary bladder cancerrdquo Mediators of Inflammation vol 2012Article ID 165879 8 pages 2012
[12] S Pinlaor Y Hiraku P Yongvanit et al ldquoiNOS-dependentDNA damage via NF-120581B expression in hamsters infected withOpisthorchis viverrini and its suppression by the antihelminthicdrug praziquantelrdquo International Journal of Cancer vol 119 no5 pp 1067ndash1072 2006
[13] S Pinlaor Y Hiraku NMa et al ldquoMechanism of NO-mediatedoxidative and nitrative DNA damage in hamsters infectedwithOpisthorchis viverrini a model of inflammation-mediatedcarcinogenesisrdquo Nitric Oxide vol 11 no 2 pp 175ndash183 2004
[14] S Pinlaor N Ma Y Hiraku et al ldquoRepeated infection withOpisthorchis viverrini induces accumulation of 8-nitroguanineand 8-oxo-78-dihydro-21015840-deoxyguanine in the bile duct ofhamsters via inducible nitric oxide synthaserdquo Carcinogenesisvol 25 no 8 pp 1535ndash1542 2004
[15] S Pinlaor P Yongvanit YHiraku et al ldquo8-Nitroguanine forma-tion in the liver of hamsters infectedwithOpisthorchis viverrinirdquoBiochemical and Biophysical Research Communications vol 309no 3 pp 567ndash571 2003
[16] S Pinlaor B Sripa N Ma et al ldquoNitrative and oxidative DNAdamage in intrahepatic cholangiocarcinoma patients in relationto tumor invasionrdquo World Journal of Gastroenterology vol 11no 30 pp 4644ndash4649 2005
[17] R Thanan C Pairojkul S Pinlaor et al ldquoInflammation-related DNA damage and expression of CD133 and Oct34 incholangiocarcinoma patients with poor prognosisrdquo Free RadicalBiology amp Medicine 2013
Oxidative Medicine and Cellular Longevity 7
[18] S Horiike S Kawanishi M Kaito et al ldquoAccumulation of 8-nitroguanine in the liver of patients with chronic hepatitis CrdquoJournal of Hepatology vol 43 no 3 pp 403ndash410 2005
[19] N Ali H Allam R May et al ldquoHepatitis C virus-inducedcancer stem cell-like signatures in cell culture and murinetumor xenograftsrdquo Journal of Virology vol 85 no 23 pp 12292ndash12303 2011
[20] K Machida H Tsukamoto H Mkrtchyan et al ldquoToll-likereceptor 4 mediates synergism between alcohol and HCVin hepatic oncogenesis involving stem cell marker NanogrdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 106 no 5 pp 1548ndash1553 2009
[21] Y Hiraku T Tabata N Ma M Murata X Ding and SKawanishi ldquoNitrative and oxidative DNA damage in cervicalintraepithelial neoplasia associatedwith humanpapilloma virusinfectionrdquo Cancer Science vol 98 no 7 pp 964ndash972 2007
[22] S-K Kim H-S Shim K-G Lee H-J An K-R Lee andN-H Cho ldquoGlassy cell carcinoma predominantly commits toa squamous lineage and is strongly associated with high-risktype human papillomavirus infectionrdquo International Journal ofGynecological Pathology vol 28 no 4 pp 389ndash395 2009
[23] S Regauer and O Reich ldquoCK17 and p16 expression pat-terns distinguish (atypical) immature squamous metaplasiafrom high-grade cervical intraepithelial neoplasia (CIN III)rdquoHistopathology vol 50 no 5 pp 629ndash635 2007
[24] W-K Liu Y-L Chu F Zhang et al ldquoThe relationship betweenHPV16 and expression of CD44v6 nm23H1 in esophagealsquamous cell carcinomardquo Archives of Virology vol 150 no 5pp 991ndash1001 2005
[25] D Liu P Zhou L Zhang et al ldquoHDAC1DNMT3A-containingcomplex is associated with suppression of Oct4 in cervicalcancer cellsrdquo Biochemistry vol 77 no 8 pp 934ndash940 2012
[26] N Ma M Kawanishi Y Hiraku et al ldquoReactive nitrogenspecies-dependent DNA damage in EBV-associated nasopha-ryngeal carcinoma the relation to STAT3 activation and EGFRexpressionrdquo International Journal of Cancer vol 122 no 11 pp2517ndash2525 2008
[27] Q-L Kong L-J Hu J-Y Cao et al ldquoEpstein-barr virus-encoded LMP2A induces an epithelialmdashmesenchymal transi-tion and increases the number of side population stem-likecancer cells in nasopharyngeal carcinomardquo PLoS Pathogens vol6 no 6 Article ID e1000940 2010
[28] A Dutton C B Woodman M B Chukwuma et al ldquoBmi-1 isinduced by the Epstein-Barr virus oncogene LMP1 and regulatesthe expression of viral target genes inHodgkin lymphoma cellsrdquoBlood vol 109 no 6 pp 2597ndash2603 2007
[29] N Ma Y Adachi Y Hiraku et al ldquoAccumulation of 8-nitroguanine in human gastric epithelium induced by Heli-cobacter pylori infectionrdquo Biochemical and Biophysical ResearchCommunications vol 319 no 2 pp 506ndash510 2004
[30] M Katsurahara Y Kobayashi M Iwasa et al ldquoReactivenitrogen species mediate DNA damage in helicobacter pylori-infected gastric mucosardquo Helicobacter vol 14 no 6 pp 552ndash558 2009
[31] Y Fujii K Yoshihashi H Suzuki et al ldquoCDX1 confers intestinalphenotype on gastric epithelial cells via induction of stemness-associated reprogramming factors SALL4 and KLF5rdquo Proceed-ings of the National Academy of Sciences of USA vol 109 no 50pp 20584ndash10589 2012
[32] J M Noto T Khizanishvili R Chaturvedi et al ldquoHelicobacterpylori promotes the expression of Kruppel-like factor 5
a mediator of carcinogenesis in vitro and in vivordquo PLoS Onevol 8 no 1 Article ID e54344 2013
[33] T Uehara D Ma Y Yao et al ldquoH pylori infection is associatedwith DNA damage of Lgr5-positive epithelial stem cells in thestomach of patients with gastric cancerrdquo Digestive Diseases andSciences vol 58 no 1 pp 140ndash149 2013
[34] X Ding Y Hiraku N Ma et al ldquoInducible nitric oxidesynthase-dependent DNA damage in mouse model of inflam-matory bowel diseaserdquoCancer Science vol 96 no 3 pp 157ndash1632005
[35] P Chaiyarit N Ma Y Hiraku et al ldquoNitrative and oxidativeDNA damage in oral lichen planus in relation to human oralcarcinogenesisrdquoCancer Science vol 96 no 9 pp 553ndash559 2005
[36] L Ma H Wang H Yao L Zhu W Liu and Z Zhou ldquoBmi1expression in oral lichen planus and the risk of progression tooral squamous cell carcinomardquo Annals of Diagnostic Pathologyvol 17 no 4 pp 327ndash330 2013
[37] A Bose M T Teh I L Hutchison H Wan I M Leigh andA Waseem ldquoTwo mechanisms regulate keratin K15 expressionin keratinocytes role of PKCAP-1 and FOXM1 mediatedsignallingrdquo PLoS One vol 7 no 6 Article ID e38599 2012
[38] RThanan NMa K Iijima et al ldquoProton pump inhibitors sup-press iNOS-dependent DNA damage in Barrettrsquos esophagus byincreasing Mn-SOD expressionrdquo Biochemical and BiophysicalResearch Communications vol 421 no 2 pp 280ndash285 2012
[39] J Mendelson S Song Y Li et al ldquoDysfunctional transform-ing growth factor-120573 signaling with constitutively active notchsignaling in Barrettrsquos esophageal adenocarcinomardquo Cancer vol117 no 16 pp 3691ndash3702 2011
[40] J Ahmad K Arthur P Maxwell et al ldquoRe grotenhuis et alBarrettrsquos oesophageal adenocarcinoma encompasses tumour-initiating cells that do not express common cancer stem cellmarkers J Pathol 2010 221 379ndash389rdquo Journal of Pathology vol224 no 1 pp 143ndash145 2011
[41] Y V Bobryshev A K Freeman N K Botelho D Tran AJ M Levert-Mignon and R V N Lord ldquoExpression of theputative stem cell marker Musashi-1 in Barrettrsquos esophagus andesophageal adenocarcinomardquoDiseases of the Esophagus vol 23no 7 pp 580ndash589 2010
[42] Y Hiraku S Kawanishi T Ichinose and M Murata ldquoThe roleof iNOS-mediated DNA damage in infection- and asbestos-induced carcinogenesisrdquo Annals of the New York Academy ofSciences vol 1203 pp 15ndash22 2010
[43] D Fukumura S Kashiwagi and R K Jain ldquoThe role of nitricoxide in tumour progressionrdquoNature Reviews Cancer vol 6 no7 pp 521ndash534 2006
[44] P K Lala and C Chakraborty ldquoRole of nitric oxide in carcino-genesis and tumour progressionrdquo Lancet Oncology vol 2 no 3pp 149ndash156 2001
[45] S Wang Z Liu L Wang and X Zhang ldquoNF-120581B signalingpathway inflammation and colorectal cancerrdquo Chinese Journalof Cellular andMolecular Immunology vol 6 no 5 pp 327ndash3342009
[46] V Yermilov J Rubio M Becchi M D Friesen B Pignatelliand H Ohshima ldquoFormation of 8-nitroguanine by the reactionof guanine with peroxynitrite in vitrordquo Carcinogenesis vol 16no 9 pp 2045ndash2050 1995
[47] B Halliwell ldquoOxygen and nitrogen are pro-carcinogens Dam-age to DNA by reactive oxygen chlorine and nitrogen speciesmeasurement mechanism and the effects of nutritionrdquo Muta-tion Research vol 443 no 1-2 pp 37ndash52 1999
8 Oxidative Medicine and Cellular Longevity
[48] R S Sodum and E S Fiala ldquoAnalysis of peroxynitrite reactionswith guanine xanthine and adenine nucleosides by high-pressure liquid chromatography with electrochemical detec-tion C8-nitration and -oxidationrdquo Chemical Research in Toxi-cology vol 14 no 4 pp 438ndash450 2001
[49] T Akaike S Fujii A Kato et al ldquoViral mutation acceleratedby nitric oxide production during infection in vivordquoThe FASEBJournal vol 14 no 10 pp 1447ndash1454 2000
[50] N Ma M Murata S Ohnishi R Thanan Y Hiraku and SKawanishi ldquo8-Nitroguanine a potential biomarker to evaluatethe risk of inflammation-related carcinogenesisrdquo in BiomarkerT K Kahn Ed chapter 10 pp 201ndash224 InTech Rijeka Croatia2012
[51] V Yermilov J Rubio and H Ohshima ldquoFormation of 8-nitroguanine in DNA treated with peroxynitrite in vitro and itsrapid removal from DNA by depurinationrdquo The FEBS Lettersvol 376 no 3 pp 207ndash210 1995
[52] L A Loeb and B D Preston ldquoMutagenesis by apurinicapyr-imidinic sitesrdquo Annual Review of Genetics vol 20 pp 201ndash2301986
[53] S Boiteux and M Guillet ldquoAbasic sites in DNA repair andbiological consequences in Saccharomyces cerevisiaerdquo DNARepair vol 3 no 1 pp 1ndash12 2004
[54] J E Sale A R Lehmann and R Woodgate ldquoY-family DNApolymerases and their role in tolerance of cellular DNA dam-agerdquo Nature Reviews Molecular Cell Biology vol 13 no 3 pp141ndash152 2012
[55] X Wu K Takenaka E Sonoda et al ldquoCritical roles forpolymerase 120577 in cellular tolerance to nitric oxide-induced DNAdamagerdquo Cancer Research vol 66 no 2 pp 748ndash754 2006
[56] N Suzuki M Yasui N E Geacintov V Shafirovich and SShibutani ldquoMiscoding events during DNA synthesis past thenitration-damaged base 8-nitroguaninerdquo Biochemistry vol 44no 25 pp 9238ndash9245 2005
[57] M Y Kim M Dong P C Dedon and G N Wogan ldquoEffects ofperoxynitrite dose and dose rate onDNAdamage andmutationin the supF shuttle vectorrdquo Chemical Research in Toxicology vol18 no 1 pp 76ndash86 2005
[58] IARC ldquoOpisthorchis viverrini and Clonorchis sinensisrdquo in AReview of Human CarcInogens Biological Agents vol 100B ofIARC Monographs on the Evaluation of Carcinogenic Risks toHumans pp 347ndash376 IARC Press Lyon France 2012
[59] J P EiserichM Hristova C E Cross et al ldquoFormation of nitricoxide-derived inflammatory oxidants by myeloperoxidase inneutrophilsrdquo Nature vol 391 no 6665 pp 393ndash397 1998
[60] J P Gaut J Byun H D Tran et al ldquoMyeloperoxidase producesnitrating oxidants in vivordquo Journal of Clinical Investigation vol109 no 10 pp 1311ndash1319 2002
[61] S Tanaka N Choe D R Hemenway S Zhu S Matalon andE Kagan ldquoAsbestos inhalation induces reactive nitrogen speciesand nitrotyrosine formation in the lungs and pleura of the ratrdquoJournal of Clinical Investigation vol 102 no 2 pp 445ndash4541998
[62] A Van Der Vliet J P Eiserich M K Shigenaga and C ECross ldquoReactive nitrogen species and tyrosine nitration in therespiratory tract epiphenomena or a pathobiologic mechanismof diseaserdquo American Journal of Respiratory and Critical CareMedicine vol 160 no 1 pp 1ndash9 1999
[63] A Haegens A Van Der Vliet K J Butnor et al ldquoAsbestos-induced lung inflammation and epithelial cell proliferation arealtered in myeloperoxidase-null micerdquoCancer Research vol 65no 21 pp 9670ndash9677 2005
[64] N Suzuki M Yasui N E Geacintov V Shafirovich and SShibutani ldquoMiscoding events during DNA synthesis past thenitration-damaged base 8-nitroguaninerdquo Biochemistry vol 44no 25 pp 9238ndash9245 2005
[65] S Shibutani M Takeshita and A P Grollman ldquoInsertionof specific bases during DNA synthesis past the oxidation-damaged base 8-oxodGrdquoNature vol 349 no 6308 pp 431ndash4341991
[66] J L Bos ldquoThe ras gene family and human carcinogenesisrdquoMutation Research vol 195 no 3 pp 255ndash271 1988
[67] S P Hussain L J Hofseth and C C Harris ldquoRadical causes ofcancerrdquoNature Reviews Cancer vol 3 no 4 pp 276ndash285 2003
[68] T Takahashi M M Nau I Chiba et al ldquop53 a frequent targetfor genetic abnormalities in lung cancerrdquo Science vol 246 no4929 pp 491ndash494 1989
[69] S Ohnishi H Saito N Suzuki et al ldquoNitrative and oxidativeDNA damage caused by K-ras mutation in micerdquo Biochemicaland Biophysical Research Communications vol 413 no 2 pp236ndash240 2011
[70] M Shipitsin and K Polyak ldquoThe cancer stem cell hypothesisin search of definitions markers and relevancerdquo LaboratoryInvestigation vol 88 no 5 pp 459ndash463 2008
[71] S Sell ldquoInfection stem cells and cancer signalsrdquo Current Phar-maceutical Biotechnology vol 12 no 2 pp 182ndash188 2011
[72] S Reuter S C Gupta M M Chaturvedi and B B AggarwalldquoOxidative stress inflammation and cancer how are theylinkedrdquo Free Radical Biology and Medicine vol 49 no 11 pp1603ndash1616 2010
[73] Y Jing Z Han Y Liu et al ldquoMesenchymal stem cellsin inflammation microenvironment accelerates hepatocellu-lar carcinoma metastasis by inducing epithelial-mesenchymaltransitionrdquo PLoS One vol 7 no 8 Article ID e43272 2012
[74] N J Maitland and A T Collins ldquoInflammation as the primaryaetiological agent of human prostate cancer a stem cell con-nectionrdquo Journal of Cellular Biochemistry vol 105 no 4 pp931ndash939 2008
[75] Z A Shaker M A Kaddah S B Hanallah and M I El-Khodary ldquoProduction of monoclonal antibodies against targetschistosomal antigen secreted in the urine of schistosomamansoni-infected patientsrdquo International Journal for Parasitol-ogy vol 28 no 12 pp 1893ndash1901 1998
[76] IARC ldquoSchistosoma haematobiumrdquo in A Review of HumanCarcInogens Biological Agents vol 100B of IARC Monographson the Evaluation of Carcinogenic Risks to Humans pp 371ndash384IARC Press Lyon France 2012
[77] E I Salim K Morimura A Menesi M El-Lity S Fukushimaand HWanibuchi ldquoElevated oxidative stress and DNA damageand repair levels in urinary bladder carcinomas associated withschistosomiasisrdquo International Journal of Cancer vol 123 no 3pp 601ndash608 2008
[78] A N Wamachi J S Mayadev P L Mungai et al ldquoIncreasedratio of tumor necrosis factor-120572 to interleukin-10 productionis associated with Schistosoma haematobium-induced urinary-tract morbidityrdquo Journal of Infectious Diseases vol 190 no 11pp 2020ndash2030 2004
[79] L H Looijenga H Stoop H P De Leeuw et al ldquoPOU5F1(OCT34) identifies cells with pluripotent potential in humangerm cell tumorsrdquo Cancer Research vol 63 no 9 pp 2244ndash2250 2003
[80] Y-C Chen H-S Hsu Y-W Chen et al ldquoOct-4 expressionmaintained cancer stem-like properties in lung cancer-derived
Oxidative Medicine and Cellular Longevity 9
CD133-positive cellsrdquo PLoS One vol 3 no 7 Article ID e26372008
[81] D Ponti A Costa N Zaffaroni et al ldquoIsolation and in vitropropagation of tumorigenic breast cancer cells with stempro-genitor cell propertiesrdquo Cancer Research vol 65 no 13 pp5506ndash5511 2005
[82] Y Matsumura and D Tarin ldquoSignificance of CD44 geneproducts for cancer diagnosis and disease evaluationrdquo Lancetvol 340 no 8827 pp 1053ndash1058 1992
[83] S Saito H Okabe M Watanabe et al ldquoCD44v6 expressionis related to mesenchymal phenotype and poor prognosis inpatients with colorectal cancerrdquo Oncology Reports vol 29 no4 pp 1570ndash1578 2013
[84] E M Peek D R Li H Zhang et al ldquoStromal modulation ofbladder cancer-initiating cells in a subcutaneous tumor modelrdquoAmerican Journal of Cancer Research vol 2 no 6 pp 745ndash7512012
[85] J Kuncova M Urban and V Mandys ldquoExpression of CD44sand CD44v6 in transitional cell carcinomas of the urinarybladder comparison with tumour grade proliferative activityand p53 immunoreactivity of tumour cellsrdquoAPMIS vol 115 no11 pp 1194ndash1205 2007
[86] M Sugiyama A Woodman T Sugino et al ldquoNon-invasivedetection of bladder cancer by identification of abnormal CD44proteins in exfoliated cancer cells in urinerdquo Journal of ClinicalMolecular Pathology vol 48 no 3 pp M142ndashM147 1995
[87] Y M Yang and J W Chang ldquoBladder cancer initiating cells(BCICs) are among EMAminusCD44v6+ subset novel methods forisolating undetermined cancer stem (initiating) cellsrdquo CancerInvestigation vol 26 no 7 pp 725ndash733 2008
[88] R Thanan S Oikawa P Yongvanit et al ldquoInflammation-induced protein carbonylation contributes to poor prognosisfor cholangiocarcinomardquo Free Radical Biology and Medicinevol 52 no 8 pp 1465ndash1472 2012
Oxidative Medicine and Cellular Longevity 7
[18] S Horiike S Kawanishi M Kaito et al ldquoAccumulation of 8-nitroguanine in the liver of patients with chronic hepatitis CrdquoJournal of Hepatology vol 43 no 3 pp 403ndash410 2005
[19] N Ali H Allam R May et al ldquoHepatitis C virus-inducedcancer stem cell-like signatures in cell culture and murinetumor xenograftsrdquo Journal of Virology vol 85 no 23 pp 12292ndash12303 2011
[20] K Machida H Tsukamoto H Mkrtchyan et al ldquoToll-likereceptor 4 mediates synergism between alcohol and HCVin hepatic oncogenesis involving stem cell marker NanogrdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 106 no 5 pp 1548ndash1553 2009
[21] Y Hiraku T Tabata N Ma M Murata X Ding and SKawanishi ldquoNitrative and oxidative DNA damage in cervicalintraepithelial neoplasia associatedwith humanpapilloma virusinfectionrdquo Cancer Science vol 98 no 7 pp 964ndash972 2007
[22] S-K Kim H-S Shim K-G Lee H-J An K-R Lee andN-H Cho ldquoGlassy cell carcinoma predominantly commits toa squamous lineage and is strongly associated with high-risktype human papillomavirus infectionrdquo International Journal ofGynecological Pathology vol 28 no 4 pp 389ndash395 2009
[23] S Regauer and O Reich ldquoCK17 and p16 expression pat-terns distinguish (atypical) immature squamous metaplasiafrom high-grade cervical intraepithelial neoplasia (CIN III)rdquoHistopathology vol 50 no 5 pp 629ndash635 2007
[24] W-K Liu Y-L Chu F Zhang et al ldquoThe relationship betweenHPV16 and expression of CD44v6 nm23H1 in esophagealsquamous cell carcinomardquo Archives of Virology vol 150 no 5pp 991ndash1001 2005
[25] D Liu P Zhou L Zhang et al ldquoHDAC1DNMT3A-containingcomplex is associated with suppression of Oct4 in cervicalcancer cellsrdquo Biochemistry vol 77 no 8 pp 934ndash940 2012
[26] N Ma M Kawanishi Y Hiraku et al ldquoReactive nitrogenspecies-dependent DNA damage in EBV-associated nasopha-ryngeal carcinoma the relation to STAT3 activation and EGFRexpressionrdquo International Journal of Cancer vol 122 no 11 pp2517ndash2525 2008
[27] Q-L Kong L-J Hu J-Y Cao et al ldquoEpstein-barr virus-encoded LMP2A induces an epithelialmdashmesenchymal transi-tion and increases the number of side population stem-likecancer cells in nasopharyngeal carcinomardquo PLoS Pathogens vol6 no 6 Article ID e1000940 2010
[28] A Dutton C B Woodman M B Chukwuma et al ldquoBmi-1 isinduced by the Epstein-Barr virus oncogene LMP1 and regulatesthe expression of viral target genes inHodgkin lymphoma cellsrdquoBlood vol 109 no 6 pp 2597ndash2603 2007
[29] N Ma Y Adachi Y Hiraku et al ldquoAccumulation of 8-nitroguanine in human gastric epithelium induced by Heli-cobacter pylori infectionrdquo Biochemical and Biophysical ResearchCommunications vol 319 no 2 pp 506ndash510 2004
[30] M Katsurahara Y Kobayashi M Iwasa et al ldquoReactivenitrogen species mediate DNA damage in helicobacter pylori-infected gastric mucosardquo Helicobacter vol 14 no 6 pp 552ndash558 2009
[31] Y Fujii K Yoshihashi H Suzuki et al ldquoCDX1 confers intestinalphenotype on gastric epithelial cells via induction of stemness-associated reprogramming factors SALL4 and KLF5rdquo Proceed-ings of the National Academy of Sciences of USA vol 109 no 50pp 20584ndash10589 2012
[32] J M Noto T Khizanishvili R Chaturvedi et al ldquoHelicobacterpylori promotes the expression of Kruppel-like factor 5
a mediator of carcinogenesis in vitro and in vivordquo PLoS Onevol 8 no 1 Article ID e54344 2013
[33] T Uehara D Ma Y Yao et al ldquoH pylori infection is associatedwith DNA damage of Lgr5-positive epithelial stem cells in thestomach of patients with gastric cancerrdquo Digestive Diseases andSciences vol 58 no 1 pp 140ndash149 2013
[34] X Ding Y Hiraku N Ma et al ldquoInducible nitric oxidesynthase-dependent DNA damage in mouse model of inflam-matory bowel diseaserdquoCancer Science vol 96 no 3 pp 157ndash1632005
[35] P Chaiyarit N Ma Y Hiraku et al ldquoNitrative and oxidativeDNA damage in oral lichen planus in relation to human oralcarcinogenesisrdquoCancer Science vol 96 no 9 pp 553ndash559 2005
[36] L Ma H Wang H Yao L Zhu W Liu and Z Zhou ldquoBmi1expression in oral lichen planus and the risk of progression tooral squamous cell carcinomardquo Annals of Diagnostic Pathologyvol 17 no 4 pp 327ndash330 2013
[37] A Bose M T Teh I L Hutchison H Wan I M Leigh andA Waseem ldquoTwo mechanisms regulate keratin K15 expressionin keratinocytes role of PKCAP-1 and FOXM1 mediatedsignallingrdquo PLoS One vol 7 no 6 Article ID e38599 2012
[38] RThanan NMa K Iijima et al ldquoProton pump inhibitors sup-press iNOS-dependent DNA damage in Barrettrsquos esophagus byincreasing Mn-SOD expressionrdquo Biochemical and BiophysicalResearch Communications vol 421 no 2 pp 280ndash285 2012
[39] J Mendelson S Song Y Li et al ldquoDysfunctional transform-ing growth factor-120573 signaling with constitutively active notchsignaling in Barrettrsquos esophageal adenocarcinomardquo Cancer vol117 no 16 pp 3691ndash3702 2011
[40] J Ahmad K Arthur P Maxwell et al ldquoRe grotenhuis et alBarrettrsquos oesophageal adenocarcinoma encompasses tumour-initiating cells that do not express common cancer stem cellmarkers J Pathol 2010 221 379ndash389rdquo Journal of Pathology vol224 no 1 pp 143ndash145 2011
[41] Y V Bobryshev A K Freeman N K Botelho D Tran AJ M Levert-Mignon and R V N Lord ldquoExpression of theputative stem cell marker Musashi-1 in Barrettrsquos esophagus andesophageal adenocarcinomardquoDiseases of the Esophagus vol 23no 7 pp 580ndash589 2010
[42] Y Hiraku S Kawanishi T Ichinose and M Murata ldquoThe roleof iNOS-mediated DNA damage in infection- and asbestos-induced carcinogenesisrdquo Annals of the New York Academy ofSciences vol 1203 pp 15ndash22 2010
[43] D Fukumura S Kashiwagi and R K Jain ldquoThe role of nitricoxide in tumour progressionrdquoNature Reviews Cancer vol 6 no7 pp 521ndash534 2006
[44] P K Lala and C Chakraborty ldquoRole of nitric oxide in carcino-genesis and tumour progressionrdquo Lancet Oncology vol 2 no 3pp 149ndash156 2001
[45] S Wang Z Liu L Wang and X Zhang ldquoNF-120581B signalingpathway inflammation and colorectal cancerrdquo Chinese Journalof Cellular andMolecular Immunology vol 6 no 5 pp 327ndash3342009
[46] V Yermilov J Rubio M Becchi M D Friesen B Pignatelliand H Ohshima ldquoFormation of 8-nitroguanine by the reactionof guanine with peroxynitrite in vitrordquo Carcinogenesis vol 16no 9 pp 2045ndash2050 1995
[47] B Halliwell ldquoOxygen and nitrogen are pro-carcinogens Dam-age to DNA by reactive oxygen chlorine and nitrogen speciesmeasurement mechanism and the effects of nutritionrdquo Muta-tion Research vol 443 no 1-2 pp 37ndash52 1999
8 Oxidative Medicine and Cellular Longevity
[48] R S Sodum and E S Fiala ldquoAnalysis of peroxynitrite reactionswith guanine xanthine and adenine nucleosides by high-pressure liquid chromatography with electrochemical detec-tion C8-nitration and -oxidationrdquo Chemical Research in Toxi-cology vol 14 no 4 pp 438ndash450 2001
[49] T Akaike S Fujii A Kato et al ldquoViral mutation acceleratedby nitric oxide production during infection in vivordquoThe FASEBJournal vol 14 no 10 pp 1447ndash1454 2000
[50] N Ma M Murata S Ohnishi R Thanan Y Hiraku and SKawanishi ldquo8-Nitroguanine a potential biomarker to evaluatethe risk of inflammation-related carcinogenesisrdquo in BiomarkerT K Kahn Ed chapter 10 pp 201ndash224 InTech Rijeka Croatia2012
[51] V Yermilov J Rubio and H Ohshima ldquoFormation of 8-nitroguanine in DNA treated with peroxynitrite in vitro and itsrapid removal from DNA by depurinationrdquo The FEBS Lettersvol 376 no 3 pp 207ndash210 1995
[52] L A Loeb and B D Preston ldquoMutagenesis by apurinicapyr-imidinic sitesrdquo Annual Review of Genetics vol 20 pp 201ndash2301986
[53] S Boiteux and M Guillet ldquoAbasic sites in DNA repair andbiological consequences in Saccharomyces cerevisiaerdquo DNARepair vol 3 no 1 pp 1ndash12 2004
[54] J E Sale A R Lehmann and R Woodgate ldquoY-family DNApolymerases and their role in tolerance of cellular DNA dam-agerdquo Nature Reviews Molecular Cell Biology vol 13 no 3 pp141ndash152 2012
[55] X Wu K Takenaka E Sonoda et al ldquoCritical roles forpolymerase 120577 in cellular tolerance to nitric oxide-induced DNAdamagerdquo Cancer Research vol 66 no 2 pp 748ndash754 2006
[56] N Suzuki M Yasui N E Geacintov V Shafirovich and SShibutani ldquoMiscoding events during DNA synthesis past thenitration-damaged base 8-nitroguaninerdquo Biochemistry vol 44no 25 pp 9238ndash9245 2005
[57] M Y Kim M Dong P C Dedon and G N Wogan ldquoEffects ofperoxynitrite dose and dose rate onDNAdamage andmutationin the supF shuttle vectorrdquo Chemical Research in Toxicology vol18 no 1 pp 76ndash86 2005
[58] IARC ldquoOpisthorchis viverrini and Clonorchis sinensisrdquo in AReview of Human CarcInogens Biological Agents vol 100B ofIARC Monographs on the Evaluation of Carcinogenic Risks toHumans pp 347ndash376 IARC Press Lyon France 2012
[59] J P EiserichM Hristova C E Cross et al ldquoFormation of nitricoxide-derived inflammatory oxidants by myeloperoxidase inneutrophilsrdquo Nature vol 391 no 6665 pp 393ndash397 1998
[60] J P Gaut J Byun H D Tran et al ldquoMyeloperoxidase producesnitrating oxidants in vivordquo Journal of Clinical Investigation vol109 no 10 pp 1311ndash1319 2002
[61] S Tanaka N Choe D R Hemenway S Zhu S Matalon andE Kagan ldquoAsbestos inhalation induces reactive nitrogen speciesand nitrotyrosine formation in the lungs and pleura of the ratrdquoJournal of Clinical Investigation vol 102 no 2 pp 445ndash4541998
[62] A Van Der Vliet J P Eiserich M K Shigenaga and C ECross ldquoReactive nitrogen species and tyrosine nitration in therespiratory tract epiphenomena or a pathobiologic mechanismof diseaserdquo American Journal of Respiratory and Critical CareMedicine vol 160 no 1 pp 1ndash9 1999
[63] A Haegens A Van Der Vliet K J Butnor et al ldquoAsbestos-induced lung inflammation and epithelial cell proliferation arealtered in myeloperoxidase-null micerdquoCancer Research vol 65no 21 pp 9670ndash9677 2005
[64] N Suzuki M Yasui N E Geacintov V Shafirovich and SShibutani ldquoMiscoding events during DNA synthesis past thenitration-damaged base 8-nitroguaninerdquo Biochemistry vol 44no 25 pp 9238ndash9245 2005
[65] S Shibutani M Takeshita and A P Grollman ldquoInsertionof specific bases during DNA synthesis past the oxidation-damaged base 8-oxodGrdquoNature vol 349 no 6308 pp 431ndash4341991
[66] J L Bos ldquoThe ras gene family and human carcinogenesisrdquoMutation Research vol 195 no 3 pp 255ndash271 1988
[67] S P Hussain L J Hofseth and C C Harris ldquoRadical causes ofcancerrdquoNature Reviews Cancer vol 3 no 4 pp 276ndash285 2003
[68] T Takahashi M M Nau I Chiba et al ldquop53 a frequent targetfor genetic abnormalities in lung cancerrdquo Science vol 246 no4929 pp 491ndash494 1989
[69] S Ohnishi H Saito N Suzuki et al ldquoNitrative and oxidativeDNA damage caused by K-ras mutation in micerdquo Biochemicaland Biophysical Research Communications vol 413 no 2 pp236ndash240 2011
[70] M Shipitsin and K Polyak ldquoThe cancer stem cell hypothesisin search of definitions markers and relevancerdquo LaboratoryInvestigation vol 88 no 5 pp 459ndash463 2008
[71] S Sell ldquoInfection stem cells and cancer signalsrdquo Current Phar-maceutical Biotechnology vol 12 no 2 pp 182ndash188 2011
[72] S Reuter S C Gupta M M Chaturvedi and B B AggarwalldquoOxidative stress inflammation and cancer how are theylinkedrdquo Free Radical Biology and Medicine vol 49 no 11 pp1603ndash1616 2010
[73] Y Jing Z Han Y Liu et al ldquoMesenchymal stem cellsin inflammation microenvironment accelerates hepatocellu-lar carcinoma metastasis by inducing epithelial-mesenchymaltransitionrdquo PLoS One vol 7 no 8 Article ID e43272 2012
[74] N J Maitland and A T Collins ldquoInflammation as the primaryaetiological agent of human prostate cancer a stem cell con-nectionrdquo Journal of Cellular Biochemistry vol 105 no 4 pp931ndash939 2008
[75] Z A Shaker M A Kaddah S B Hanallah and M I El-Khodary ldquoProduction of monoclonal antibodies against targetschistosomal antigen secreted in the urine of schistosomamansoni-infected patientsrdquo International Journal for Parasitol-ogy vol 28 no 12 pp 1893ndash1901 1998
[76] IARC ldquoSchistosoma haematobiumrdquo in A Review of HumanCarcInogens Biological Agents vol 100B of IARC Monographson the Evaluation of Carcinogenic Risks to Humans pp 371ndash384IARC Press Lyon France 2012
[77] E I Salim K Morimura A Menesi M El-Lity S Fukushimaand HWanibuchi ldquoElevated oxidative stress and DNA damageand repair levels in urinary bladder carcinomas associated withschistosomiasisrdquo International Journal of Cancer vol 123 no 3pp 601ndash608 2008
[78] A N Wamachi J S Mayadev P L Mungai et al ldquoIncreasedratio of tumor necrosis factor-120572 to interleukin-10 productionis associated with Schistosoma haematobium-induced urinary-tract morbidityrdquo Journal of Infectious Diseases vol 190 no 11pp 2020ndash2030 2004
[79] L H Looijenga H Stoop H P De Leeuw et al ldquoPOU5F1(OCT34) identifies cells with pluripotent potential in humangerm cell tumorsrdquo Cancer Research vol 63 no 9 pp 2244ndash2250 2003
[80] Y-C Chen H-S Hsu Y-W Chen et al ldquoOct-4 expressionmaintained cancer stem-like properties in lung cancer-derived
Oxidative Medicine and Cellular Longevity 9
CD133-positive cellsrdquo PLoS One vol 3 no 7 Article ID e26372008
[81] D Ponti A Costa N Zaffaroni et al ldquoIsolation and in vitropropagation of tumorigenic breast cancer cells with stempro-genitor cell propertiesrdquo Cancer Research vol 65 no 13 pp5506ndash5511 2005
[82] Y Matsumura and D Tarin ldquoSignificance of CD44 geneproducts for cancer diagnosis and disease evaluationrdquo Lancetvol 340 no 8827 pp 1053ndash1058 1992
[83] S Saito H Okabe M Watanabe et al ldquoCD44v6 expressionis related to mesenchymal phenotype and poor prognosis inpatients with colorectal cancerrdquo Oncology Reports vol 29 no4 pp 1570ndash1578 2013
[84] E M Peek D R Li H Zhang et al ldquoStromal modulation ofbladder cancer-initiating cells in a subcutaneous tumor modelrdquoAmerican Journal of Cancer Research vol 2 no 6 pp 745ndash7512012
[85] J Kuncova M Urban and V Mandys ldquoExpression of CD44sand CD44v6 in transitional cell carcinomas of the urinarybladder comparison with tumour grade proliferative activityand p53 immunoreactivity of tumour cellsrdquoAPMIS vol 115 no11 pp 1194ndash1205 2007
[86] M Sugiyama A Woodman T Sugino et al ldquoNon-invasivedetection of bladder cancer by identification of abnormal CD44proteins in exfoliated cancer cells in urinerdquo Journal of ClinicalMolecular Pathology vol 48 no 3 pp M142ndashM147 1995
[87] Y M Yang and J W Chang ldquoBladder cancer initiating cells(BCICs) are among EMAminusCD44v6+ subset novel methods forisolating undetermined cancer stem (initiating) cellsrdquo CancerInvestigation vol 26 no 7 pp 725ndash733 2008
[88] R Thanan S Oikawa P Yongvanit et al ldquoInflammation-induced protein carbonylation contributes to poor prognosisfor cholangiocarcinomardquo Free Radical Biology and Medicinevol 52 no 8 pp 1465ndash1472 2012
8 Oxidative Medicine and Cellular Longevity
[48] R S Sodum and E S Fiala ldquoAnalysis of peroxynitrite reactionswith guanine xanthine and adenine nucleosides by high-pressure liquid chromatography with electrochemical detec-tion C8-nitration and -oxidationrdquo Chemical Research in Toxi-cology vol 14 no 4 pp 438ndash450 2001
[49] T Akaike S Fujii A Kato et al ldquoViral mutation acceleratedby nitric oxide production during infection in vivordquoThe FASEBJournal vol 14 no 10 pp 1447ndash1454 2000
[50] N Ma M Murata S Ohnishi R Thanan Y Hiraku and SKawanishi ldquo8-Nitroguanine a potential biomarker to evaluatethe risk of inflammation-related carcinogenesisrdquo in BiomarkerT K Kahn Ed chapter 10 pp 201ndash224 InTech Rijeka Croatia2012
[51] V Yermilov J Rubio and H Ohshima ldquoFormation of 8-nitroguanine in DNA treated with peroxynitrite in vitro and itsrapid removal from DNA by depurinationrdquo The FEBS Lettersvol 376 no 3 pp 207ndash210 1995
[52] L A Loeb and B D Preston ldquoMutagenesis by apurinicapyr-imidinic sitesrdquo Annual Review of Genetics vol 20 pp 201ndash2301986
[53] S Boiteux and M Guillet ldquoAbasic sites in DNA repair andbiological consequences in Saccharomyces cerevisiaerdquo DNARepair vol 3 no 1 pp 1ndash12 2004
[54] J E Sale A R Lehmann and R Woodgate ldquoY-family DNApolymerases and their role in tolerance of cellular DNA dam-agerdquo Nature Reviews Molecular Cell Biology vol 13 no 3 pp141ndash152 2012
[55] X Wu K Takenaka E Sonoda et al ldquoCritical roles forpolymerase 120577 in cellular tolerance to nitric oxide-induced DNAdamagerdquo Cancer Research vol 66 no 2 pp 748ndash754 2006
[56] N Suzuki M Yasui N E Geacintov V Shafirovich and SShibutani ldquoMiscoding events during DNA synthesis past thenitration-damaged base 8-nitroguaninerdquo Biochemistry vol 44no 25 pp 9238ndash9245 2005
[57] M Y Kim M Dong P C Dedon and G N Wogan ldquoEffects ofperoxynitrite dose and dose rate onDNAdamage andmutationin the supF shuttle vectorrdquo Chemical Research in Toxicology vol18 no 1 pp 76ndash86 2005
[58] IARC ldquoOpisthorchis viverrini and Clonorchis sinensisrdquo in AReview of Human CarcInogens Biological Agents vol 100B ofIARC Monographs on the Evaluation of Carcinogenic Risks toHumans pp 347ndash376 IARC Press Lyon France 2012
[59] J P EiserichM Hristova C E Cross et al ldquoFormation of nitricoxide-derived inflammatory oxidants by myeloperoxidase inneutrophilsrdquo Nature vol 391 no 6665 pp 393ndash397 1998
[60] J P Gaut J Byun H D Tran et al ldquoMyeloperoxidase producesnitrating oxidants in vivordquo Journal of Clinical Investigation vol109 no 10 pp 1311ndash1319 2002
[61] S Tanaka N Choe D R Hemenway S Zhu S Matalon andE Kagan ldquoAsbestos inhalation induces reactive nitrogen speciesand nitrotyrosine formation in the lungs and pleura of the ratrdquoJournal of Clinical Investigation vol 102 no 2 pp 445ndash4541998
[62] A Van Der Vliet J P Eiserich M K Shigenaga and C ECross ldquoReactive nitrogen species and tyrosine nitration in therespiratory tract epiphenomena or a pathobiologic mechanismof diseaserdquo American Journal of Respiratory and Critical CareMedicine vol 160 no 1 pp 1ndash9 1999
[63] A Haegens A Van Der Vliet K J Butnor et al ldquoAsbestos-induced lung inflammation and epithelial cell proliferation arealtered in myeloperoxidase-null micerdquoCancer Research vol 65no 21 pp 9670ndash9677 2005
[64] N Suzuki M Yasui N E Geacintov V Shafirovich and SShibutani ldquoMiscoding events during DNA synthesis past thenitration-damaged base 8-nitroguaninerdquo Biochemistry vol 44no 25 pp 9238ndash9245 2005
[65] S Shibutani M Takeshita and A P Grollman ldquoInsertionof specific bases during DNA synthesis past the oxidation-damaged base 8-oxodGrdquoNature vol 349 no 6308 pp 431ndash4341991
[66] J L Bos ldquoThe ras gene family and human carcinogenesisrdquoMutation Research vol 195 no 3 pp 255ndash271 1988
[67] S P Hussain L J Hofseth and C C Harris ldquoRadical causes ofcancerrdquoNature Reviews Cancer vol 3 no 4 pp 276ndash285 2003
[68] T Takahashi M M Nau I Chiba et al ldquop53 a frequent targetfor genetic abnormalities in lung cancerrdquo Science vol 246 no4929 pp 491ndash494 1989
[69] S Ohnishi H Saito N Suzuki et al ldquoNitrative and oxidativeDNA damage caused by K-ras mutation in micerdquo Biochemicaland Biophysical Research Communications vol 413 no 2 pp236ndash240 2011
[70] M Shipitsin and K Polyak ldquoThe cancer stem cell hypothesisin search of definitions markers and relevancerdquo LaboratoryInvestigation vol 88 no 5 pp 459ndash463 2008
[71] S Sell ldquoInfection stem cells and cancer signalsrdquo Current Phar-maceutical Biotechnology vol 12 no 2 pp 182ndash188 2011
[72] S Reuter S C Gupta M M Chaturvedi and B B AggarwalldquoOxidative stress inflammation and cancer how are theylinkedrdquo Free Radical Biology and Medicine vol 49 no 11 pp1603ndash1616 2010
[73] Y Jing Z Han Y Liu et al ldquoMesenchymal stem cellsin inflammation microenvironment accelerates hepatocellu-lar carcinoma metastasis by inducing epithelial-mesenchymaltransitionrdquo PLoS One vol 7 no 8 Article ID e43272 2012
[74] N J Maitland and A T Collins ldquoInflammation as the primaryaetiological agent of human prostate cancer a stem cell con-nectionrdquo Journal of Cellular Biochemistry vol 105 no 4 pp931ndash939 2008
[75] Z A Shaker M A Kaddah S B Hanallah and M I El-Khodary ldquoProduction of monoclonal antibodies against targetschistosomal antigen secreted in the urine of schistosomamansoni-infected patientsrdquo International Journal for Parasitol-ogy vol 28 no 12 pp 1893ndash1901 1998
[76] IARC ldquoSchistosoma haematobiumrdquo in A Review of HumanCarcInogens Biological Agents vol 100B of IARC Monographson the Evaluation of Carcinogenic Risks to Humans pp 371ndash384IARC Press Lyon France 2012
[77] E I Salim K Morimura A Menesi M El-Lity S Fukushimaand HWanibuchi ldquoElevated oxidative stress and DNA damageand repair levels in urinary bladder carcinomas associated withschistosomiasisrdquo International Journal of Cancer vol 123 no 3pp 601ndash608 2008
[78] A N Wamachi J S Mayadev P L Mungai et al ldquoIncreasedratio of tumor necrosis factor-120572 to interleukin-10 productionis associated with Schistosoma haematobium-induced urinary-tract morbidityrdquo Journal of Infectious Diseases vol 190 no 11pp 2020ndash2030 2004
[79] L H Looijenga H Stoop H P De Leeuw et al ldquoPOU5F1(OCT34) identifies cells with pluripotent potential in humangerm cell tumorsrdquo Cancer Research vol 63 no 9 pp 2244ndash2250 2003
[80] Y-C Chen H-S Hsu Y-W Chen et al ldquoOct-4 expressionmaintained cancer stem-like properties in lung cancer-derived
Oxidative Medicine and Cellular Longevity 9
CD133-positive cellsrdquo PLoS One vol 3 no 7 Article ID e26372008
[81] D Ponti A Costa N Zaffaroni et al ldquoIsolation and in vitropropagation of tumorigenic breast cancer cells with stempro-genitor cell propertiesrdquo Cancer Research vol 65 no 13 pp5506ndash5511 2005
[82] Y Matsumura and D Tarin ldquoSignificance of CD44 geneproducts for cancer diagnosis and disease evaluationrdquo Lancetvol 340 no 8827 pp 1053ndash1058 1992
[83] S Saito H Okabe M Watanabe et al ldquoCD44v6 expressionis related to mesenchymal phenotype and poor prognosis inpatients with colorectal cancerrdquo Oncology Reports vol 29 no4 pp 1570ndash1578 2013
[84] E M Peek D R Li H Zhang et al ldquoStromal modulation ofbladder cancer-initiating cells in a subcutaneous tumor modelrdquoAmerican Journal of Cancer Research vol 2 no 6 pp 745ndash7512012
[85] J Kuncova M Urban and V Mandys ldquoExpression of CD44sand CD44v6 in transitional cell carcinomas of the urinarybladder comparison with tumour grade proliferative activityand p53 immunoreactivity of tumour cellsrdquoAPMIS vol 115 no11 pp 1194ndash1205 2007
[86] M Sugiyama A Woodman T Sugino et al ldquoNon-invasivedetection of bladder cancer by identification of abnormal CD44proteins in exfoliated cancer cells in urinerdquo Journal of ClinicalMolecular Pathology vol 48 no 3 pp M142ndashM147 1995
[87] Y M Yang and J W Chang ldquoBladder cancer initiating cells(BCICs) are among EMAminusCD44v6+ subset novel methods forisolating undetermined cancer stem (initiating) cellsrdquo CancerInvestigation vol 26 no 7 pp 725ndash733 2008
[88] R Thanan S Oikawa P Yongvanit et al ldquoInflammation-induced protein carbonylation contributes to poor prognosisfor cholangiocarcinomardquo Free Radical Biology and Medicinevol 52 no 8 pp 1465ndash1472 2012
Oxidative Medicine and Cellular Longevity 9
CD133-positive cellsrdquo PLoS One vol 3 no 7 Article ID e26372008
[81] D Ponti A Costa N Zaffaroni et al ldquoIsolation and in vitropropagation of tumorigenic breast cancer cells with stempro-genitor cell propertiesrdquo Cancer Research vol 65 no 13 pp5506ndash5511 2005
[82] Y Matsumura and D Tarin ldquoSignificance of CD44 geneproducts for cancer diagnosis and disease evaluationrdquo Lancetvol 340 no 8827 pp 1053ndash1058 1992
[83] S Saito H Okabe M Watanabe et al ldquoCD44v6 expressionis related to mesenchymal phenotype and poor prognosis inpatients with colorectal cancerrdquo Oncology Reports vol 29 no4 pp 1570ndash1578 2013
[84] E M Peek D R Li H Zhang et al ldquoStromal modulation ofbladder cancer-initiating cells in a subcutaneous tumor modelrdquoAmerican Journal of Cancer Research vol 2 no 6 pp 745ndash7512012
[85] J Kuncova M Urban and V Mandys ldquoExpression of CD44sand CD44v6 in transitional cell carcinomas of the urinarybladder comparison with tumour grade proliferative activityand p53 immunoreactivity of tumour cellsrdquoAPMIS vol 115 no11 pp 1194ndash1205 2007
[86] M Sugiyama A Woodman T Sugino et al ldquoNon-invasivedetection of bladder cancer by identification of abnormal CD44proteins in exfoliated cancer cells in urinerdquo Journal of ClinicalMolecular Pathology vol 48 no 3 pp M142ndashM147 1995
[87] Y M Yang and J W Chang ldquoBladder cancer initiating cells(BCICs) are among EMAminusCD44v6+ subset novel methods forisolating undetermined cancer stem (initiating) cellsrdquo CancerInvestigation vol 26 no 7 pp 725ndash733 2008
[88] R Thanan S Oikawa P Yongvanit et al ldquoInflammation-induced protein carbonylation contributes to poor prognosisfor cholangiocarcinomardquo Free Radical Biology and Medicinevol 52 no 8 pp 1465ndash1472 2012
![Microproteinuria during Opisthorchis viverriniInfection: A ......liver flukes Opisthorchis viverrini and Clonorchis sinensis [1]. In Southeast Asia alone, up to 67 million people are](https://static.documents.pub/doc/80x56/604a246ab262a95d9267572c/microproteinuria-during-opisthorchis-viverriniinfection-a-liver-flukes.jpg)
