of 51
PhD programMolecular Signal Tranduction
TUMOR ANGIOGENESIS
Erhard Hofer
Department of Vascular Biology and Thrombosis ResearchCenter for Biomolecular Medicine and PharmacologyMedical University of Vienna
Part I: Overview of vessel formation
1- Angiogenesis and vasculogenesis
2- Important factors and receptors
3- VEGF receptor signaling
4- Tumor angiogenesis
5- Anti-angiogenesis therapies
Literature:
Books:
B. Alberts et al., Molecular Biology of the Cell,5th Edition, Taylor and Francis Inc., 2007Pg. 1279-1283
R.A. Weinberg, The Biology of Cancer, Garland Science, 2007Pg. 556-585
Tumor Angiogenesis - Basic mechanisms and Cancer Therapy, D. Marme, N. Fusenig, ed.Springer Verlag 2008
Angiogenesis - From basic science to clinical applicationN. Ferrara, ed.CRC Press, Taylor&Francis Group, 2007
Nature Insight Angiogenesis G.D. Yancopoulos et al. (2000). Vascular-specific growth factors and blood vessel formation. Nature 407, 242-248.
Angiogenesis Focus, Nature Med 9, June 2003Peter Carmeliet, Angiogenesis in Health and DiseaseNapoleone Ferrara et al., The biology of VEGF and its receptorsRakesh K. Jain, Molecular regulation of vessel maturationShanin Rafii and David Lyden, Therapeutic stem and progenitor celltransplantation for organ vascularization and regenerationChristopher W. Pugh and Peter J. Ratcliffe, Regulation of angiogenesis by hypoxia: role of the HIF system
Angiogenesis, Nature Reviews Cancer 3, June 2003 Gabriele Bergers and Laura E. Benjamin, Tumorigenesis and the angiogenic switch
Literature:
Reviews:
C.J. Schofield and P.J. Ratcliffe. Oxygen sensing by HIF hydroxylases.Nature Rev. Mol. Cell Biol. 5, 343-354 (2004)
Nature Insight Angiogenesis, Vol. 438, pg. 931-974, December 2005Carmeliet, Angiogenesis in life, disease and medicine Coultas, Endothelial cells and VEGF in vascular development Alitalo, Lymphangiogenesis in development and human disease Greenberg, From angiogenesis to neuropathology Gariano, Retinal angiogenesis in development and disease Ferrara, Angiogenesis as a therapeutic target
P. Carmeliet and M. Tessier-Lavigne, Common mechanisms of nerve and blood vessel wiring, Nature 436, 195-200 (2005)
J. Folkman, Angiogenesis: an organizing principle for drug discovery ?Nature Reviews Drug Discovery 6, 273-286 (2007)
Role of notch:Adams and Alitalo, Molecular regulation of angiogenesis and lymphangiogenesis, Nature Rev Mol Cell Biol 8, 464-478 (2007)Germain et al., Hypoxia-driven angiogenesis, Curr Opinion in Hematol 17 (2010)
Guidance cues:Larrivee et al., Guidance of vascular development: Lessons from the nervous system, Circulation Research 104, 428-441 (2009)Gaur et al., Role of class 3 semaphorins and their receptors in tumor growth and angiogenesis, Clin Cancer Res 15, 6763-70 (2009)
Unterlagen:
http://mailbox.univie.ac.at/erhard.hoferStudent point, Vorlesungsunterlagen
Structure of vessels and capillariesMonocellular layer of endothelial cellsSmall artery:Capillary: endothelial cell, basal lamina, pericytes
Angiogenesis:Sprouting of cells from mature endothelial cells of the vessel wall
Mouse cornea:wounding induces angiogenesis,chemotactic response toangiogenic factors(secretion of proteases, resolution ofBasal lamina, migration towards Chemotactic gradient, proliferation,Tube formation)
VEGF is factor largely specific for endothelial cells,bFGF can also induce, not specific for EC)
Sprouting towards chemotactic gradient: VEGF
Hypoxia - HIF - VEGFevery cell must be within 50 to 100 mm of a capillaryHIF: hypoxia inducible factorVEGF: vascular endothelial growth factor
VEGF-gene:Regulated by HIF,HIF is continously produced,ubiquitinylated, degraded in proteasome,therefore low concentration;
Ubiquitinylation dependent onHippel-Lindau tumor suppressor(part of an E3 ubiquitin-ligase complex)
HIF1ais modified by a prolyl hydroxylase,then better interaction with vHL protein, high turnover;Hydroxylase is regulated by O2
Von Hippel-Lindau Tumor Suppressor, HIF and VEGF
capillaries sprouting in the retina of an embryonic mouse
capillary lumen opening up behind the tip cell(red dye injected)
Vasculogenesis
Formation of vessels by differentiation of cells from angioblasts in the yolk sac of the embryo:
Is differentiation and proliferation of endothelial cells in a non-vascularized tissue
Leads to formation of a primitive tubular network
Has to undergo angiogenic remodeling to stable vascular system
HemangioblastAngioblastECPostnatal vasculogenesis
Factors and receptors
Endothelium-specific factors:VEGF family: 5 factorsAngiopoietin family : 4 factorsEphrin family : at least 1 factor
Non EC-specific factors :bFGFPDGFTGF-b
VEGF/VEGFR:VEGF-A: initiation of vasculogenesisand sprouting angiogenesis,Immature vessels,Vascular permeability factor,Haploid insufficiency in k.o. mice,
PlGF: remodeling of adult vessels VEGF-B: heart vascularization ?VEGF-C: lymphatic vesselsVEGF-D: lymphatic vessels ?
VEGFR-2: growth and permeabilityVEGFR-1: negative role ?, decoy receptor,synergism with VEGFR-2 in tumor angiogenesis VEGFR-3: lymphatic vessels
VEGF/VEGFR family
Figure 13.31 The Biology of Cancer ( Garland Science 2007)Network of lymphatic vessels (red) and capillaries (green):Lymphatic vessels are larger, not supported by underlying mural cells
Differential signaling by tyr kinase receptorsgene regulation
proliferationvasculogenesisangiogenesis
Y799Y820Y925Y936Y951Y994Y1006Y1052Y1057Y1080Y1104Y1128Y1134Y1175Y1212Y1221Y1303Y1307Y1317P38, src (vascular leakage?)
TSAd (migration)
PI-3 kinase (survival)
PLC-g
EC specific factors/receptors:
VEGFR1VEGF-A, PLGFVEGFR2VEGF-AVEGFR3VEGF-CTIE1?TIE2ANG1,2VEGFR2Sakurai et al.PNAS 2005
82 of the most strongly VEGF-regulated genes (over 5-fold) compared to EGF and IL-1 inductionVEGF + EGF + IL-1 clusterVEGF + IL-1 clusterVEGF + EGF clusterVEGF cluster
Overlapping and specific gene repertoiresof VEGF, EGF and IL-1About 60 genes reproducibly induced by VEGF over 3-fold
VEGF-induced genes overlap to a large degreewith IL1-induced genes (50-60 %)
20 % of genes are preferentially induced by VEGF
Signaling by receptors of endothelial cellsIL-1R
VEGFR-2EGFRHofer E., Schweighofer B. Signaling transduction induced in endothelial cells by growth factor receptors involved in angiogenesis. Thrombosis ang haemostasis 2007IL-1VEGF-AEGF
Guidance molecules in endothelial tip cell attraction and repulsionEichmann A, Curr Opin Neurobiol. 2005 Carmeliet P, Nature. 2005
Angiopoietins und Tie Receptors:
Ang1: remodeling and maturationQuiescence and stabilityResistance to permeability,Supports interaction with other cells and matrix,Vessel size (VEGF number of vessels),Repair of damaged vessels
Ang2: natural antagonist,Overexpression similar Ang-1 k.o. oder Tie-2 k.o.,Destabilization signal for initiation of vascular remodelingEither regression or increased VEGF sensitivityAng2 is induced in tumors
Ang3: ?Ang4: ?
Tie2: binds Ang1-4
Tie1: ?
Ephrins und Eph-Receptors:
Largest family of growth factor receptors,Relevant for vascular system:Ephrin B2/ Eph B4 : remodeling and maturation Different for early arterial (Ephrin B2) and venous vessels (EphB4),Hypothesis: role for fusion of arterial/venous vessels
1-Sprouting3-incorporation of BM-derived precursors5-LymphangiogenesisGrowth of tumor vessels2-Intussusceptive growth4-Cooption of existing vessels
Role of VEGF and Ang2 for tumor angiogenesis,VEGF-blockade is promising for anti-ngiogenesis therapyConcept 2: many tumors home in onto vessels, occupate existing vessels,Vessel produces Ang2, first tumor regression, then VEGF production by tumor Concept 1: non-vascularized Tumor
Figure 13.32a The Biology of Cancer ( Garland Science 2007)Recruitment of capillaries by an implanted tumor
Figure 13.34a The Biology of Cancer ( Garland Science 2007)Chaotic organization of tumor-associated vasculature
Structure and function of tumor vessels:
Chaotic architecture and blood flowTherefore hypoxic and acidic regions in tumorPermeability strongly increasedfenestraeenlarged JunctionsNo functional lymphatics inside the tumorenlarged in surrounding,increases metastasis
Mosaic vessels
Abnormale endothelium
Figure 13.33 The Biology of Cancer ( Garland Science 2007)Tumor vessel is only partially overlaid by pericytes and SMC
Figure 13.37 The Biology of Cancer ( Garland Science 2007)The Rip-Tag model of islet tumor cell progressionTransgene: SV40 large and small T transcription driven by insulin promoterTranscription in b-cells of islets of Langerhans
Figure 13.38b The Biology of Cancer ( Garland Science 2007)The angiogenic switch and recruitment of inflammatory cells
Figure 13.49 The Biology of Cancer ( Garland Science 2007)Heterotypic interactions as targets for therapeutic intervention
Inhibition of tumor angiogenesis1-Bevacizumab2-VEGF-trap3-Pegaptinib(Combination with 5-fluorouracil forcolorectal cancer)(Macular degeneration)45- SU11248 Bay43-90066- downstream Signals ?
BevacizumabColorectal cancerPhase IIICombination therapy
Hurwitz et al. 2004Mass et al. 2004
IFL: Irinotecan5-fluorouracilLeucovorin
Median survival benefitof two trials (2004):3.7-4.7 months
Gentherapien:
rAdenovirenrRetroviren
Targeting of viruses to tumors, tumor endothelium
Targeting of liposomes to tumors, tumor endothelium
Oncolytic viruses
BM progenitor cells home to tumor vasculature
Next meeting in Zrich, June 15-18, 2011organized by Michael Detmar, ETH
Ralf Adams, Max-Planck-Institute, Mnster, Germany
Kari Alitalo, University of Helsinki, Finland
Hirofumi Arakawa, National Cancer Center Research Institute, Tokyo, Japan
Hellmut Augustin, German Cancer Research Center, Heidelberg, Germany
Roy Bicknell, University of Birmingham, UK
Georg Breier, Technical University Dresden, Germany
Peter Carmeliet, Catholic University of Leuven, Belgium
Michael Detmar, Swiss Federal Institute of Technology Zurich, Switzerland
Anna Dimberg, Uppsala University, Sweden
Anne Eichmann, INSERM U833, College de France, Paris, France
Britta Engelhardt, University of Bern, Switzerland
Napoleone Ferrara, Genentech Inc., San Francisco, USA
Holger Gerhardt, London Research Institute, Cancer Research UK
Dontscho Kerjaschki, Medical University of Vienna, Austria
Alexander Koch, Genentech Inc., San Francisco, USA
Donald McDonald, University of California, San Francisco, USA
Gera Neufeld, Israel Institute of Technology, Haifa, Israel
Jaques Pouyssegur, Institute of Developmental Biology and Cancer, Nice, France
Masabumi Shibuya, University of Tokyo, Japan
Dietmar Vestweber, Max-Planck-Institute, Mnster, Germany
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