Chromophobe RCC
Elizabeth (Lisa) Petri Henske, MDDirector, Center for LAM Research and Clinical Care,
Brigham and Women’s Hospital, Boston MAProfessor of Medicine, Harvard Medical School
Medical Oncologist, Dana Farber Cancer InstituteAssociate Member, The Broad Institute of MIT and Harvard
Brigham and Women’s Hospital/Dana-Farber Cancer Institute
Harvard Medical School
Growing chRCC Team!
BWH: Carmen Priolo
David KwiatkowskiDamir Khabibulllin
Long Zhang
DFCI:David BraunToni Choueiri
Sabina SignorettiMatthew Freedman
+ Others!
Wei Shi (MGH)John Asara (Beth Israel, Boston)
Ed Reznik (MSKCC)
National Cancer Institute/NIH (RO1)
US Department of Defense Kidney Cancer Program (Hypothesis Award)
The Tuttle Family
Lymphangioleiomyomatosis (LAM)
Angiomyolipomas
ChRCC can occur in Tuberous Sclerosis Complex and Birt-Hogg-Dube Syndrome
Renal Cell Carcinoma
Tuberous Sclerosis Complex
Birt-Hogg-Dube
5% of all sporadic renal cancers Occur in BHD and TSCFilled with abnormal mitochondria Losses of chromosomes 1, 2, 6, 10, 13 and 17Few driver mutations (TCGA: ~50%: p53, Tsc1, PIK3CA)
4
Chromophobe RCC
• 367 measured metabolites • 188 differential metabolites
TumorNormal
*Glucose metabolism*Glutathione metabolism
Metabolomics: Nine chRCC vs. matched normal kidney
7.00
6.00
5.00
4.00
3.00
2.00
1.00
0.00
-1.00
-log10(p)
log2(FC)-8.00 -7.00 -6.00 -5.00 -4.00 -3.00 -2.00 -1.00 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00
5-oxoproline
Ɣglutamylleucine
Ɣglutamylglutamate
Top differential metabolites in ChRCC compared to normal kidney
Features selected by volcano plot with fold change threshold 2(FC; x) and t-tests threshold p <0.01 (y). The red circlesrepresent features above the threshold. The further the redcircle is away from the (0,0), the more significant the feature is.
Normal kidneyTumor36 metabolites decreased in tumor vs normal
Decreased expression of gamma-glutamyl transferase 1 (GGT1) in ChRCC
nsp<0.001
GGT1 gene locus= Chr 22q11.23 RNA seq data from TCGA
n=25 n=66 n=18 n=82
The glutathione salvage pathway (or gamma-glutamyl cycle)
• gamma-glutamyl transferase 1(GGT1): membranetranspeptidase
• transfers gamma-glutamylmoieties from extracellularGSH, GSSG, or GSHconjugates to an amino acidacceptor (gamma-glutamylamino acid)
• GGT-deficient mice: lowerGSH levels, increased DNAdamage (Rojas et al, 1999),and dysfunctional mitochondria(Will et al, 2000)
GCLC= Glutamate-cysteine ligase catalytic subunit GSS= glutathione synthetaseSLC7A11= cystine-glutamate antiporter
GCLC
GSS
Enhanced expression of glutathione biosynthetic enzymes in ChRCC
10
GGT1 downregulation increases De Novo Glutathione Synthesis
CB-839
Priolo C, Khabibullin D,… Henske EP. PNAS 2018HEK293,72h
GGT1 down-regulation sensitizes HEK203 to inhibition of glutathione biosynthesis
Damir Khabibullin
BSO=buthionine sulfoximine48-hr treatment after 72-hr transfection with siGGT1 or siControl
Working model and Future Directions
Hypothesis: Defects in the Ɣ-glutamyl cycle lead to accumulation of damaged mitochondria and tumorigenesis
Compensatory metabolic reprogramming Impaired response to oxidative stress
• Role in renal tumorigenesis• Increased sensitivity to agents that inhibit glutathione synthesis
Oxidative stresscaused by an imbalance between production and accumulation of oxygen reactive species (ROS) and the ability to detoxify these reactive products
GlutathioneAn anti-oxidant, helps detoxify reactive oxygen species
MitochondriaCellular powerhouses or “batteries” that make ATP and can generate reactive oxygen species, especially when they are damaged
Major Roadblock: chRCC Models
• Additional cell lines• Additional animal models
15
• Chromophobe RCC with sarcomatoid differentiation
• Clonal losses of chromosomes 1, 3, 4, 11, 13, 14, and 19 and gains of X, Y, 6, 8, and 20. – (vs ChRCC losses of chromosomes 1,
2, 6, 10, 13 and 17)
• TP53 missense mutation
Genes Chromosomes and Cancer, 2017
H E K 2 9 3 U O K 2 7 60 .0
0 .5
1 .0
1 .5
Re
lati
ve
GG
T1
mR
NA
Low GGT1 in UOK276 relative to HEK293
GGT1Chromo1039 cellsChromo1039 Tissue
GGT1
ChromoA cells
ChRCC-derived primary cell lines: low GGT1 expression
A
B
(Gerharz et al., Am J Path, 1995)
SNP arrays, 250K
Take Home Hypothesis: Defective glutathione salvage pathway (or gamma-glutamyl cycle)
Chromophobe RCC may have altered sensitivity to oxidative stress
Chromophobe RCC
Elizabeth (Lisa) Petri Henske, MDDirector, Center for LAM Research and Clinical Care,
Brigham and Women’s Hospital, Boston MAProfessor of Medicine, Harvard Medical School
Medical Oncologist, Dana Farber Cancer InstituteAssociate Member, The Broad Institute of MIT and Harvard