It is generally assumed that recurrent mutations within a given cancer driver gene elicit similar drug responses. Cancer genome studies have identified recurrent but divergent missense mutations affecting the substrate-recognition domain of the ubiquitin ligase adaptor SPOP in endometrial and prostate cancers. The therapeutic implications of these mutations remain incompletely understood. Here we analyzed changes in the ubiquitin landscape induced by endometrial cancer–associated SPOP mutations and identified BRD2, BRD3 and BRD4 proteins (BETs) as SPOP–CUL3 substrates that are preferentially degraded by endometrial cancer–associated SPOP mutants. The resulting reduction of BET protein levels sensitized cancer cells to BET inhibitors. Conversely, prostate cancer–specific SPOP mutations resulted in impaired degradation of BETs, promoting their resistance to pharmacologic inhibition. These results uncover an oncogenomics paradox, whereby mutations mapping to the same domain evoke opposing drug susceptibilities. Specifically, we provide a molecular rationale for the use of BET inhibitors to treat patients with endometrial but not prostate cancer who harbor SPOP mutations.
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Roychowdhury, S. & Chinnaiyan, A.M. Translating genomics for precision cancer medicine. Annu. Rev. Genomics Hum. Genet. 15, 395–415 (2014).
Barbieri, C.E. et al. Exome sequencing identifies recurrent SPOP, FOXA1 and MED12 mutations in prostate cancer. Nat. Genet. 44, 685–689 (2012).
Blattner, M. et al. SPOP mutations in prostate cancer across demographically diverse patient cohorts. Neoplasia 16, 14–20 (2014).
Le Gallo, M. et al. Exome sequencing of serous endometrial tumors identifies recurrent somatic mutations in chromatin-remodeling and ubiquitin ligase complex genes. Nat. Genet. 44, 1310–1315 (2012).
Jones, S. et al. Genomic analyses of gynaecologic carcinosarcomas reveal frequent mutations in chromatin remodelling genes. Nat. Commun. 5, 5006 (2014).
Kandoth, C. et al. Integrated genomic characterization of endometrial carcinoma. Nature 497, 67–73 (2013).
Zhuang, M. et al. Structures of SPOP–substrate complexes: insights into molecular architectures of BTB–Cul3 ubiquitin ligases. Mol. Cell 36, 39–50 (2009).
Theurillat, J.P. et al. Ubiquitylome analysis identifies dysregulation of effector substrates in SPOP-mutant prostate cancer. Science 346, 85–89 (2014).
Geng, C. et al. Prostate cancer–associated mutations in speckle-type POZ protein (SPOP) regulate steroid receptor coactivator 3 protein turnover. Proc. Natl. Acad. Sci. USA 110, 6997–7002 (2013).
Gan, W. et al. SPOP promotes ubiquitination and degradation of the ERG oncoprotein to suppress prostate cancer progression. Mol. Cell 59, 917–930 (2015).
An, J. et al. Truncated ERG oncoproteins from TMPRSS2-ERG fusions are resistant to SPOP-mediated proteasome degradation. Mol. Cell 59, 904–916 (2015).
Geng, C. et al. Androgen receptor is the key transcriptional mediator of the tumor suppressor SPOP in prostate cancer. Cancer Res. 74, 5631–5643 (2014).
Nishida, M., Kasahara, K., Kaneko, M., Iwasaki, H. & Hayashi, K. Establishment of a new human endometrial adenocarcinoma cell line, Ishikawa cells, containing estrogen and progesterone receptors. Nihon Sanka Fujinka Gakkai Zasshi 37, 1103–1111 (1985).
Udeshi, N.D., Mertins, P., Svinkina, T. & Carr, S.A. Large-scale identification of ubiquitination sites by mass spectrometry. Nat. Protoc. 8, 1950–1960 (2013).
Tsai, W.W. et al. TRIM24 links a non-canonical histone signature to breast cancer. Nature 468, 927–932 (2010).
Salmans, M.L., Zhao, F. & Andersen, B. The estrogen-regulated anterior gradient 2 (AGR2) protein in breast cancer: a potential drug target and biomarker. Breast Cancer Res. 15, 204 (2013).
Groner, A.C. et al. TRIM24 is an oncogenic transcriptional activator in prostate cancer. Cancer Cell 29, 846–858 (2016).
Jung, M., Gelato, K.A., Fernández-Montalván, A., Siegel, S. & Haendler, B. Targeting BET bromodomains for cancer treatment. Epigenomics 7, 487–501 (2015).
Blattner, M. et al. SPOP mutation drives prostate tumorigenesis in vivo through coordinate regulation of PI3K/mTOR and AR signaling. Cancer Cell 31, 436–451 (2017).
Kwon, J.E. et al. BTB domain–containing speckle-type POZ protein (SPOP) serves as an adaptor of Daxx for ubiquitination by Cul3-based ubiquitin ligase. J. Biol. Chem. 281, 12664–12672 (2006).
Shi, J. & Vakoc, C.R. The mechanisms behind the therapeutic activity of BET bromodomain inhibition. Mol. Cell 54, 728–736 (2014).
Stonestrom, A.J. et al. Functions of BET proteins in erythroid gene expression. Blood 125, 2825–2834 (2015).
Wang, C.Y. & Filippakopoulos, P. Beating the odds: BETs in disease. Trends Biochem. Sci. 40, 468–479 (2015).
Asangani, I.A. et al. Therapeutic targeting of BET bromodomain proteins in castration-resistant prostate cancer. Nature 510, 278–282 (2014).
Filippakopoulos, P. et al. Selective inhibition of BET bromodomains. Nature 468, 1067–1073 (2010).
Boi, M. et al. The BET bromodomain inhibitor OTX015 affects pathogenetic pathways in preclinical B-cell tumor models and synergizes with targeted drugs. Clin. Cancer Res. 21, 1628–1638 (2015).
Shu, S. et al. Response and resistance to BET bromodomain inhibitors in triple-negative breast cancer. Nature 529, 413–417 (2016).
Sahai, V., Redig, A.J., Collier, K.A., Eckerdt, F.D. & Munshi, H.G. Targeting BET bromodomain proteins in solid tumors. Oncotarget 7, 53997–54009 (2016).
Lockwood, W.W., Zejnullahu, K., Bradner, J.E. & Varmus, H. Sensitivity of human lung adenocarcinoma cell lines to targeted inhibition of BET epigenetic signaling proteins. Proc. Natl. Acad. Sci. USA 109, 19408–19413 (2012).
Gibson, W.J. et al. The genomic landscape and evolution of endometrial carcinoma progression and abdominopelvic metastasis. Nat. Genet. 48, 848–855 (2016).
Cancer Genome Atlas Research Network. The molecular taxonomy of primary prostate cancer. Cell 163, 1011–1025 (2015).
Kumar, A. et al. Substantial interindividual and limited intraindividual genomic diversity among tumors from men with metastatic prostate cancer. Nat. Med. 22, 369–378 (2016).
Robinson, D. et al. Integrative clinical genomics of advanced prostate cancer. Cell 161, 1215–1228 (2015).
Kurimchak, A.M. et al. Resistance to BET bromodomain inhibitors is mediated by kinome reprogramming in ovarian cancer. Cell Rep. 16, 1273–1286 (2016).
Marcotte, R. et al. Functional genomic landscape of human breast cancer drivers, vulnerabilities, and resistance. Cell 164, 293–309 (2016).
Shi, X. et al. Loss of TRIM33 causes resistance to BET bromodomain inhibitors through MYC- and TGF-β-dependent mechanisms. Proc. Natl. Acad. Sci. USA 113, E4558–E4566 (2016).
Bendall, S.C. et al. Prevention of amino acid conversion in SILAC experiments with embryonic stem cells. Mol. Cell. Proteomics 7, 1587–1597 (2008).
Mertins, P. et al. Integrated proteomic analysis of post-translational modifications by serial enrichment. Nat. Methods 10, 634–637 (2013).
Enchev, R.I. et al. Structural basis for a reciprocal regulation between SCF and CSN. Cell Rep. 2, 616–627 (2012).
Mosadeghi, R. et al. Structural and kinetic analysis of the COP9-signalosome activation and the cullin-RING ubiquitin ligase deneddylation cycle. eLife 5, e12102 (2016).
Barretina, J. et al. The Cancer Cell Line Encyclopedia enables predictive modelling of anticancer drug sensitivity. Nature 483, 603–607 (2012).
Mortezavi, A. et al. KPNA2 expression is an independent adverse predictor of biochemical recurrence after radical prostatectomy. Clin. Cancer Res. 17, 1111–1121 (2011).
Lebeau, A. et al. Oestrogen receptor gene (ESR1) amplification is frequent in endometrial carcinoma and its precursor lesions. J. Pathol. 216, 151–157 (2008).
Wild, P.J. et al. p53 suppresses type II endometrial carcinomas in mice and governs endometrial tumour aggressiveness in humans. EMBO Mol. Med. 4, 808–824 (2012).
Dellas, A., Jundt, G., Sartorius, G., Schneider, M. & Moch, H. Combined PTEN and p27kip1 protein expression patterns are associated with obesity and prognosis in endometrial carcinomas. Clin. Cancer Res. 15, 2456–2462 (2009).
We thank M. Losa, M. Storz, P. Schraml, S. Dettwiler and F. Prutek for help with tissue handling and histology assistance. We thank Q. Zhong for his help with the next-generation sequencing bioinformatics pipeline. We thank all members of the IRB animal core facility for technical assistance and the animal work. We thank E. Samartzis and K. Dedes (University Hospital Zurich) for providing AN3CA, HEC1A, HEC1B, HEC116, SNG-II, EFE184 and KLE cell lines. We thank the Oregon Health & Science University (OHSU) and the Cooperative Human Tissue Network (CHTN) for the tissue repository. We also thank all members of the laboratory for scientific discussions. J.-P.P.T. is funded by a Swiss National Science Foundation Professorship (PP00P3_150645) grant, a Swiss Cancer League (KSL-3654-02-2015) grant, a grant by the Jubiläumsstiftung Swiss Life AG and a grant by the Vontobel Stiftung. The Swiss National Science Foundation (310030B_160312/1), the European Research Council (268930), SystemsX IPhD (2013/128), Krebsforschungs Schweiz (KFS-3498-08-2014) and a GRL grant from the Korean government fund M.P. This work was also funded in part by a grant to P.J.W. provided by Oncosuisse (KLS-3384-02-2014-R) and the Foundation for Research in Science and the Humanities at the University of Zurich (SWF).
L.A.G. is a paid consultant of the following pharmaceutical companies: Novartis Foundation Medicine, Boehringer INgelheim and Millennium/Takeda. The authors declare no additional competing financial interests.
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Janouskova, H., El Tekle, G., Bellini, E. et al. Opposing effects of cancer-type-specific SPOP mutants on BET protein degradation and sensitivity to BET inhibitors. Nat Med 23, 1046–1054 (2017). https://doi.org/10.1038/nm.4372
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