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Prostate cancer–associated SPOP mutations confer resistance to BET inhibitors through stabilization of BRD4

Abstract

The bromodomain and extraterminal (BET) family of proteins comprises four members—BRD2, BRD3, BRD4 and the testis-specific isoform BRDT—that largely function as transcriptional coactivators1,2,3 and play critical roles in various cellular processes, including the cell cycle, apoptosis, migration and invasion4,5. BET proteins enhance the oncogenic functions of major cancer drivers by elevating the expression of these drivers, such as c-Myc in leukemia6,7, or by promoting the transcriptional activities of oncogenic factors, such as AR and ERG in prostate cancer8. Pathologically, BET proteins are frequently overexpressed and are clinically linked to various types of human cancer5,9,10; they are therefore being pursued as attractive therapeutic targets for selective inhibition in patients with cancer. To this end, a number of bromodomain inhibitors, including JQ1 and I-BET, have been developed11,12 and have shown promising outcomes in early clinical trials. Although resistance to BET inhibitors has been documented in preclinical models13,14,15, the molecular mechanisms underlying acquired resistance are largely unknown. Here we report that cullin-3SPOP earmarks BET proteins, including BRD2, BRD3 and BRD4, for ubiquitination-mediated degradation. Pathologically, prostate cancer–associated SPOP mutants fail to interact with and promote the degradation of BET proteins, leading to their elevated abundance in SPOP-mutant prostate cancer. As a result, prostate cancer cell lines and organoids derived from individuals harboring SPOP mutations are more resistant to BET-inhibitor-induced cell growth arrest and apoptosis. Therefore, our results elucidate the tumor-suppressor role of SPOP in prostate cancer in which it acts as a negative regulator of BET protein stability and also provide a molecular mechanism for resistance to BET inhibitors in individuals with prostate cancer bearing SPOP mutations.

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Figure 1: The CUL3SPOP E3 ubiquitin ligase negatively regulates the stability of BET proteins.
Figure 2: Prostate cancer–associated SPOP mutants promote prostate tumorigenesis by elevating levels of BET proteins.
Figure 3: SPOP promotes ubiquitination and subsequent destruction of BET proteins in a degron-dependent manner.
Figure 4: BRD4 protein abundance induces resistance of SPOP-deficient prostate cancer cells to BET inhibitors.

References

  1. 1

    Zeng, L. & Zhou, M.M. Bromodomain: an acetyl-lysine binding domain. FEBS Lett. 513, 124–128 (2002).

    CAS  Article  Google Scholar 

  2. 2

    Wu, S.Y. & Chiang, C.M. The double bromodomain–containing chromatin adaptor Brd4 and transcriptional regulation. J. Biol. Chem. 282, 13141–13145 (2007).

    CAS  Article  Google Scholar 

  3. 3

    Filippakopoulos, P. & Knapp, S. The bromodomain interaction module. FEBS Lett. 586, 2692–2704 (2012).

    CAS  Article  Google Scholar 

  4. 4

    Filippakopoulos, P. & Knapp, S. Targeting bromodomains: epigenetic readers of lysine acetylation. Nat. Rev. Drug Discov. 13, 337–356 (2014).

    CAS  Article  Google Scholar 

  5. 5

    Belkina, A.C. & Denis, G.V. BET domain co-regulators in obesity, inflammation and cancer. Nat. Rev. Cancer 12, 465–477 (2012).

    CAS  Article  Google Scholar 

  6. 6

    Delmore, J.E. et al. BET bromodomain inhibition as a therapeutic strategy to target c-Myc. Cell 146, 904–917 (2011).

    CAS  Article  Google Scholar 

  7. 7

    Mertz, J.A. et al. Targeting MYC dependence in cancer by inhibiting BET bromodomains. Proc. Natl. Acad. Sci. USA 108, 16669–16674 (2011).

    CAS  Article  Google Scholar 

  8. 8

    Asangani, I.A. et al. Therapeutic targeting of BET bromodomain proteins in castration-resistant prostate cancer. Nature 510, 278–282 (2014).

    CAS  Article  Google Scholar 

  9. 9

    French, C.A. et al. BRD4-NUT fusion oncogene: a novel mechanism in aggressive carcinoma. Cancer Res. 63, 304–307 (2003).

    CAS  PubMed  Google Scholar 

  10. 10

    Crawford, N.P. et al. Bromodomain 4 activation predicts breast cancer survival. Proc. Natl. Acad. Sci. USA 105, 6380–6385 (2008).

    CAS  Article  Google Scholar 

  11. 11

    Filippakopoulos, P. et al. Selective inhibition of BET bromodomains. Nature 468, 1067–1073 (2010).

    CAS  Article  Google Scholar 

  12. 12

    Nicodeme, E. et al. Suppression of inflammation by a synthetic histone mimic. Nature 468, 1119–1123 (2010).

    CAS  Article  Google Scholar 

  13. 13

    Fong, C.Y. et al. BET inhibitor resistance emerges from leukaemia stem cells. Nature 525, 538–542 (2015).

    CAS  Article  Google Scholar 

  14. 14

    Rathert, P. et al. Transcriptional plasticity promotes primary and acquired resistance to BET inhibition. Nature 525, 543–547 (2015).

    CAS  Article  Google Scholar 

  15. 15

    Shu, S. et al. Response and resistance to BET bromodomain inhibitors in triple-negative breast cancer. Nature 529, 413–417 (2016).

    CAS  Article  Google Scholar 

  16. 16

    Holohan, C., Van Schaeybroeck, S., Longley, D.B. & Johnston, P.G. Cancer drug resistance: an evolving paradigm. Nat. Rev. Cancer 13, 714–726 (2013).

    CAS  Article  Google Scholar 

  17. 17

    Gottesman, M.M. Mechanisms of cancer drug resistance. Annu. Rev. Med. 53, 615–627 (2002).

    CAS  Article  Google Scholar 

  18. 18

    Housman, G. et al. Drug resistance in cancer: an overview. Cancers (Basel) 6, 1769–1792 (2014).

    CAS  Article  Google Scholar 

  19. 19

    Genschik, P., Sumara, I. & Lechner, E. The emerging family of CULLIN3–RING ubiquitin ligases (CRL3s): cellular functions and disease implications. EMBO J. 32, 2307–2320 (2013).

    CAS  Article  Google Scholar 

  20. 20

    Vitari, A.C. et al. COP1 is a tumour suppressor that causes degradation of ETS transcription factors. Nature 474, 403–406 (2011).

    CAS  Article  Google Scholar 

  21. 21

    Jang, M.K. et al. The bromodomain protein Brd4 is a positive regulatory component of P-TEFb and stimulates RNA polymerase II–dependent transcription. Mol. Cell 19, 523–534 (2005).

    CAS  Article  Google Scholar 

  22. 22

    Yang, Z. et al. Recruitment of P-TEFb for stimulation of transcriptional elongation by the bromodomain protein Brd4. Mol. Cell 19, 535–545 (2005).

    CAS  Article  Google Scholar 

  23. 23

    Wu, S.Y., Lee, A.Y., Lai, H.T., Zhang, H. & Chiang, C.M. Phospho switch triggers Brd4 chromatin binding and activator recruitment for gene-specific targeting. Mol. Cell 49, 843–857 (2013).

    CAS  Article  Google Scholar 

  24. 24

    Zhuang, M. et al. Structures of SPOP–substrate complexes: insights into molecular architectures of BTB–Cul3 ubiquitin ligases. Mol. Cell 36, 39–50 (2009).

    CAS  Article  Google Scholar 

  25. 25

    Barbieri, C.E. et al. Exome sequencing identifies recurrent SPOP, FOXA1 and MED12 mutations in prostate cancer. Nat. Genet. 44, 685–689 (2012).

    CAS  Article  Google Scholar 

  26. 26

    Cancer Genome Atlas Research Network. The molecular taxonomy of primary prostate cancer. Cell 163, 1011–1025 (2015).

  27. 27

    Theurillat, J.P. et al. Ubiquitylome analysis identifies dysregulation of effector substrates in SPOP-mutant prostate cancer. Science 346, 85–89 (2014).

    CAS  Article  Google Scholar 

  28. 28

    Gan, W. et al. SPOP promotes ubiquitination and degradation of the ERG oncoprotein to suppress prostate cancer progression. Mol. Cell 59, 917–930 (2015).

    CAS  Article  Google Scholar 

  29. 29

    Zhong, Q. et al. Image-based computational quantification and visualization of genetic alterations and tumour heterogeneity. Sci. Rep. 6, 24146 (2016).

    CAS  Article  Google Scholar 

  30. 30

    Lu, G. et al. The myeloma drug lenalidomide promotes the cereblon-dependent destruction of Ikaros proteins. Science 343, 305–309 (2014).

    CAS  Article  Google Scholar 

  31. 31

    Krönke, J. et al. Lenalidomide causes selective degradation of IKZF1 and IKZF3 in multiple myeloma cells. Science 343, 301–305 (2014).

    Article  Google Scholar 

  32. 32

    Winter, G.E. et al. Phthalimide conjugation as a strategy for in vivo target protein degradation. Science 348, 1376–1381 (2015).

    CAS  Article  Google Scholar 

  33. 33

    Kumar-Sinha, C., Tomlins, S.A. & Chinnaiyan, A.M. Recurrent gene fusions in prostate cancer. Nat. Rev. Cancer 8, 497–511 (2008).

    CAS  Article  Google Scholar 

  34. 34

    Rubin, M.A., Maher, C.A. & Chinnaiyan, A.M. Common gene rearrangements in prostate cancer. J. Clin. Oncol. 29, 3659–3668 (2011).

    CAS  Article  Google Scholar 

  35. 35

    Gao, D. et al. Organoid cultures derived from patients with advanced prostate cancer. Cell 159, 176–187 (2014).

    CAS  Article  Google Scholar 

  36. 36

    Wei, W. et al. Degradation of the SCF component Skp2 in cell-cycle phase G1 by the anaphase-promoting complex. Nature 428, 194–198 (2004).

    CAS  Article  Google Scholar 

  37. 37

    Boehm, J.S., Hession, M.T., Bulmer, S.E. & Hahn, W.C. Transformation of human and murine fibroblasts without viral oncoproteins. Mol. Cell. Biol. 25, 6464–6474 (2005).

    CAS  Article  Google Scholar 

  38. 38

    Inuzuka, H. et al. Phosphorylation by casein kinase I promotes the turnover of the Mdm2 oncoprotein via the SCFβ-TRCP ubiquitin ligase. Cancer Cell 18, 147–159 (2010).

    CAS  Article  Google Scholar 

  39. 39

    Drost, J. et al. Organoid culture systems for prostate epithelial and cancer tissue. Nat. Protoc. 11, 347–358 (2016).

    CAS  Article  Google Scholar 

  40. 40

    Gao, J. et al. Integrative analysis of complex cancer genomics and clinical profiles using the cBioPortal. Sci. Signal. 6, pl1 (2013).

    Article  Google Scholar 

  41. 41

    Humphrey, P.A., Moch, H., Cubilla, A.L., Ulbright, T.M. & Reuter, V.E. The 2016 WHO Classification of Tumours of the Urinary System and Male Genital Organs—Part B: Prostate and Bladder Tumours. Eur. Urol. 70, 106–119 (2016).

    Article  Google Scholar 

Download references

Acknowledgements

We thank N. Mitsiades (Baylor College of Medicine), P. Zhou (Weill Cornell Medical College), W. Kaelin (Dana-Farber Cancer Institute), C. French (Brigham and Women's Hospital), R.-H. Chen (Institute of Biological Chemistry, Academia Sinica), S. Uchida (Tokyo Medical and Dental University), J. Yuan (Harvard Medical School) and S.-Y. Shao (Beth Israel Deaconess Medical Center) for their contributed materials. We thank F. Wu, B. Wang, N.T. Nihira and B. North for critical reading of the manuscript and members of the Wei and Bradner laboratories for useful discussions. X.D. and J.G. are supported by a National Research Service Award T-32 training grant. W.G. is supported by 1K99CA207867 from the National Cancer Institute. D.L.B. is a Merck Fellow of the Damon Runyon Cancer Research Foundation (DRG-2196-14). P.J.W. is funded in part by a H2020 grant from the European Commission (PrECISE) and a research grant from the University of Zurich, Switzerland. W.W. is an American Cancer Society research scholar. This work was supported in part by National Institutes of Health grants (W.W., GM094777 and CA177910).

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X.D., W.G. and X.L. designed and performed most of the experiments with assistance from J.G., J.Z., K.S., H.I., P.L., L.W. and L.A.G. W.Z., Q.Z., L.B., P.J.W. and J.H. performed IHC. X.D., W.G., J.G., J.Z., S.L., T.C. and K.-K.W. performed the xenograft assays. L.H., S.W., S.K.M. and Y.C. performed the 3D cell culture assays. F.B. and A.H.B. performed the bioinformatics analysis. D.V., M.B., M.A.R. and C.E.B. performed assays with transgenic mice. D.L.B., J.Q. and J.E.B. provided BET inhibitors and performed related drug treatment. W.W. designed the experiments and supervised the study. W.G., X.D. and W.W. wrote the manuscript. All authors commented on the manuscript.

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Correspondence to Wenyi Wei.

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The authors declare no competing financial interests.

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Dai, X., Gan, W., Li, X. et al. Prostate cancer–associated SPOP mutations confer resistance to BET inhibitors through stabilization of BRD4. Nat Med 23, 1063–1071 (2017). https://doi.org/10.1038/nm.4378

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