Expression of the androgen receptor splice variant 7 (AR-V7) is frequently detected in castrate resistant prostate cancer and associated with resistance to AR-targeted therapies. While we have previously noted that homodimerization is required for the transcriptional activity of AR-V7 and that AR-V7 can also form heterodimers with the full-length AR (AR-FL), there are still many gaps of knowledge in AR-V7 stepwise activation. In the present study, we show that neither AR-V7 homodimerization nor AR-V7/AR-FL heterodimerization requires cofactors or DNA binding. AR-V7 can enter the nucleus as a monomer and drive a transcriptional program and DNA-damage repair as a homodimer. While forming a heterodimer with AR-FL to induce nuclear localization of unliganded AR-FL, AR-V7 does not need to interact with AR-FL to drive gene transcription or DNA-damage repair in prostate cancer cells that co-express AR-V7 and AR-FL. These data indicate that AR-V7 can function independently of its interaction with AR-FL in the true castrate state or “absence of ligand”, providing support for the utility of targeting AR-V7 in improving outcomes of patients with castrate resistant prostate cancer.
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de Bono J, Eisenberger M, Sartor O. Abiraterone in metastatic prostate cancer. N Engl J Med. 2017;377:1694–5.
Davis ID, Martin AJ, Stockler MR, Begbie S, Chi KN, Chowdhury S, et al. Enzalutamide with standard first-line therapy in metastatic prostate cancer. N Engl J Med. 2019;381:121–31.
Hussain M, Fizazi K, Saad F, Rathenborg P, Shore N, Ferreira U, et al. Enzalutamide in men with nonmetastatic, castration-resistant prostate cancer. N Engl J Med. 2018;378:2465–74.
Loriot Y, Fizazi K, de Bono JS, Forer D, Hirmand M, Scher HI. Enzalutamide in castration-resistant prostate cancer patients with visceral disease in the liver and/or lung: Outcomes from the randomized controlled phase 3 AFFIRM trial. Cancer. 2017;123:253–62.
Sartor O, de Bono JS. Metastatic prostate cancer. N Engl J Med. 2018;378:1653–4.
Yuan X, Cai C, Chen S, Chen S, Yu Z, Balk SP. Androgen receptor functions in castration-resistant prostate cancer and mechanisms of resistance to new agents targeting the androgen axis. Oncogene. 2014;33:2815–25.
Cao S, Zhan Y, Dong Y. Emerging data on androgen receptor splice variants in prostate cancer. Endocr Relat Cancer. 2016;23:T199–T210.
Robinson D, Van Allen EM, Wu YM, Schultz N, Lonigro RJ, Mosquera JM, et al. Integrative clinical genomics of advanced prostate cancer. Cell. 2015;161:1215–28.
Sharp A, Coleman I, Yuan W, Sprenger C, Dolling D, Rodrigues DN, et al. Androgen receptor splice variant-7 expression emerges with castration resistance in prostate cancer. J Clin Invest. 2019;129:192–208.
Antonarakis ES, Lu C, Wang H, Luber B, Nakazawa M, Roeser JC, et al. AR-V7 and resistance to enzalutamide and abiraterone in prostate cancer. N Engl J Med. 2014;371:1028–38.
Scher HI, Lu D, Schreiber NA, Louw J, Graf RP, Vargas HA, et al. Association of AR-V7 on circulating tumor cells as a treatment-specific biomarker with outcomes and survival in castration-resistant prostate cancer. JAMA Oncol. 2016;2:1441–9.
Todenhofer T, Azad A, Stewart C, Gao J, Eigl BJ, Gleave ME, et al. AR-V7 transcripts in whole blood RNA of patients with metastatic castration resistant prostate cancer correlate with response to abiraterone acetate. J Urol. 2017;197:135–42.
Welti J, Rodrigues DN, Sharp A, Sun S, Lorente D, Riisnaes R, et al. Analytical validation and clinical qualification of a new immunohistochemical assay for androgen receptor splice variant-7 protein expression in metastatic castration-resistant prostate cancer. Eur Urol. 2016;70:599–608.
Sharp A, Welti JC, Lambros MBK, Dolling D, Rodrigues DN, Pope L, et al. Clinical utility of circulating tumour cell androgen receptor splice variant-7 status in metastatic castration-resistant prostate cancer. Eur Urol. 2019;76:676–85.
Hornberg E, Ylitalo EB, Crnalic S, Antti H, Stattin P, Widmark A, et al. Expression of androgen receptor splice variants in prostate cancer bone metastases is associated with castration-resistance and short survival. PLoS ONE. 2011;6:e19059.
Dehm SM, Schmidt LJ, Heemers HV, Vessella RL, Tindall DJ. Splicing of a novel androgen receptor exon generates a constitutively active androgen receptor that mediates prostate cancer therapy resistance. Cancer Res. 2008;68:5469–77.
Sun S, Sprenger CC, Vessella RL, Haugk K, Soriano K, Mostaghel EA, et al. Castration resistance in human prostate cancer is conferred by a frequently occurring androgen receptor splice variant. J Clin Invest. 2010;120:2715–30.
Guo Z, Yang X, Sun F, Jiang R, Linn DE, Chen H, et al. A novel androgen receptor splice variant is up-regulated during prostate cancer progression and promotes androgen depletion-resistant growth. Cancer Res. 2009;69:2305–13.
Hu R, Dunn TA, Wei S, Isharwal S, Veltri RW, Humphreys E, et al. Ligand-independent androgen receptor variants derived from splicing of cryptic exons signify hormone-refractory prostate cancer. Cancer Res. 2009;69:16–22.
Cao B, Qi Y, Zhang G, Xu D, Zhan Y, Alvarez X, et al. Androgen receptor splice variants activating the full-length receptor in mediating resistance to androgen-directed therapy. Oncotarget. 2014;5:1646–56. (1802 pii)
Li Y, Chan SC, Brand LJ, Hwang TH, Silverstein KA, Dehm SM. Androgen receptor splice variants mediate enzalutamide resistance in castration-resistant prostate cancer cell lines. Cancer Res. 2013;73:483–9.
Mostaghel EA, Marck BT, Plymate SR, Vessella RL, Balk S, Matsumoto AM, et al. Resistance to CYP17A1 inhibition with abiraterone in castration-resistant prostate cancer: induction of steroidogenesis and androgen receptor splice variants. Clin Cancer Res. 2011;17:5913–25.
Nadiminty N, Tummala R, Liu C, Yang J, Lou W, Evans CP, et al. NF-kappaB2/p52 induces resistance to enzalutamide in prostate cancer: role of androgen receptor and its variants. Mol Cancer Ther. 2013;12:1629–37.
Krause WC, Shafi AA, Nakka M, Weigel NL. Androgen receptor and its splice variant, AR-V7, differentially regulate FOXA1 sensitive genes in LNCaP prostate cancer cells. Int J Biochem Cell Biol. 2014;54:49–59.
Lu J, Lonergan PE, Nacusi LP, Wang L, Schmidt LJ, Sun Z, et al. The cistrome and gene signature of androgen receptor splice variants in castration resistant prostate cancer cells. J Urol. 2015;193:690–8.
Chan SC, Selth LA, Li Y, Nyquist MD, Miao L, Bradner JE, et al. Targeting chromatin binding regulation of constitutively active AR variants to overcome prostate cancer resistance to endocrine-based therapies. Nucleic Acids Res. 2015;43:5880–97.
He Y, Lu J, Ye Z, Hao S, Wang L, Kohli M, et al. Androgen receptor splice variants bind to constitutively open chromatin and promote abiraterone-resistant growth of prostate cancer. Nucleic Acids Res. 2018;46:1895–911.
Chen Z, Wu D, Thomas-Ahner JM, Lu C, Zhao P, Zhang Q, et al. Diverse AR-V7 cistromes in castration-resistant prostate cancer are governed by HoxB13. Proc Natl Acad Sci USA. 2018;115:6810–5.
Cato L, de Tribolet-Hardy J, Lee I, Rottenberg JT, Coleman I, Melchers D, et al. ARv7 represses tumor-suppressor genes in castration-resistant prostate cancer. Cancer Cell. 2019;35:401–13 e406.
Hu R, Lu C, Mostaghel EA, Yegnasubramanian S, Gurel M, Tannahill C, et al. Distinct transcriptional programs mediated by the ligand-dependent full-length androgen receptor and its splice variants in castration-resistant prostate cancer. Cancer Res. 2012;72:3457–62.
Lu J, Lonergan PE, Nacusi LP, Wang L, Schmidt LJ, Sun Z, et al. The cistrome and gene signature of androgen receptor splice variants in castration-resistant prostate cancer cells. J Urol. 2014;193:690–8.
Shafi AA, Putluri V, Arnold JM, Tsouko E, Maity S, Roberts JM, et al. Differential regulation of metabolic pathways by androgen receptor (AR) and its constitutively active splice variant, AR-V7, in prostate cancer cells. Oncotarget. 2015;6:31997–2012.
Magani F, Bray ER, Martinez MJ, Zhao N, Copello VA, Heidman L, et al. Identification of an oncogenic network with prognostic and therapeutic value in prostate cancer. Mol Syst Biol. 2018;14:e8202.
Cai L, Tsai YH, Wang P, Wang J, Li D, Fan H, et al. ZFX mediates non-canonical oncogenic functions of the androgen receptor splice variant 7 in castrate-resistant prostate cancer. Mol Cell. 2018;72:341–54. e346.
Yin Y, Li R, Xu K, Ding S, Li J, Baek G, et al. Androgen receptor variants mediate DNA repair after prostate cancer irradiation. Cancer Res. 2017;77:4745–54.
Xu D, Zhan Y, Qi Y, Cao B, Bai S, Xu W, et al. Androgen receptor splice variants dimerize to transactivate target genes. Cancer Res. 2015;75:3663–71.
Zhan Y, Zhang G, Wang X, Qi Y, Bai S, Li D, et al. Interplay between cytoplasmic and nuclear androgen receptor splice variants mediates castration resistance. Mol Cancer Res. 2017;15:59–68.
Uo T, Dvinge H, Sprenger CC, Bradley RK, Nelson PS, Plymate SR. Systematic and functional characterization of novel androgen receptor variants arising from alternative splicing in the ligand-binding domain. Oncogene. 2017;36:1440–50.
Hu R, Isaacs WB, Luo J. A snapshot of the expression signature of androgen receptor splicing variants and their distinctive transcriptional activities. Prostate. 2011;71:1656–67.
Chan SC, Li Y, Dehm SM. Androgen receptor splice variants activate androgen receptor target genes and support aberrant prostate cancer cell growth independent of canonical androgen receptor nuclear localization signal. J Biol Chem. 2012;287:19736–49.
Kohli M, Ho Y, Hillman DW, Van Etten JL, Henzler C, Yang R, et al. Androgen receptor variant AR-V9 is coexpressed with AR-V7 in prostate cancer metastases and predicts abiraterone resistance. Clin Cancer Res. 2017;23:4704–15.
Nyquist MD, Li Y, Hwang TH, Manlove LS, Vessella RL, Silverstein KA, et al. TALEN-engineered AR gene rearrangements reveal endocrine uncoupling of androgen receptor in prostate cancer. Proc Natl Acad Sci USA. 2013;110:17492–7.
Watson PA, Chen YF, Balbas MD, Wongvipat J, Socci ND, Viale A, et al. Constitutively active androgen receptor splice variants expressed in castration-resistant prostate cancer require full-length androgen receptor. Proc Natl Acad Sci USA. 2010;107:16759–65.
Dubbink HJ, Hersmus R, Verma CS, van der Korput HA, Berrevoets CA, van Tol J, et al. Distinct recognition modes of FXXLF and LXXLL motifs by the androgen receptor. Mol Endocrinol. 2004;18:2132–50.
van Royen ME, van Cappellen WA, de VC, Houtsmuller AB, Trapman J. Stepwise androgen receptor dimerization. JCell Sci. 2012;125:1970–9.
Shaffer PL, Jivan A, Dollins DE, Claessens F, Gewirth DT. Structural basis of androgen receptor binding to selective androgen response elements. Proc Natl Acad Sci USA. 2004;101:4758–63.
Kounatidou E, Nakjang S, McCracken SRC, Dehm SM, Robson CN, Jones D, et al. A novel CRISPR-engineered prostate cancer cell line defines the AR-V transcriptome and identifies PARP inhibitor sensitivities. Nucleic Acids Res. 2019;47:5634–47.
Cai C, Balk SP. Intratumoral androgen biosynthesis in prostate cancer pathogenesis and response to therapy. EndocrRelat Cancer. 2011;18:R175–82.
Ta HQ, Dworak N, Ivey ML, Roller DG, Gioeli DAR. phosphorylation and CHK2 kinase activity regulates IR-stabilized AR–CHK2 interaction and prostate cancer survival. eLife. 2020;9:e51378.
Bai S, Cao S, Jin L, Kobelski M, Schouest B, Wang X, et al. A positive role of c-Myc in regulating androgen receptor and its splice variants in prostate cancer. Oncogene. 2019;38:4977–89.
Dong Y, Zhang H, Gao AC, Marshall JR, Ip C. Androgen receptor signaling intensity is a key factor in determining the sensitivity of prostate cancer cells to selenium inhibition of growth and cancer-specific biomarkers. Mol Cancer Ther. 2005;4:1047–55.
Li B, Dewey CN. RSEM: accurate transcript quantification from RNA-Seq data with or without a reference genome. BMC Bioinforma. 2011;12:323.
Anders S, Huber W. Differential expression analysis for sequence count data. Genome Biol. 2010;11:R106.
Cao S, Ma T, Ungerleider N, Roberts C, Kobelski M, Jin L, et al. Circular RNAs add diversity to androgen receptor isoform repertoire in castration-resistant prostate cancer. Oncogene. 2019;38:7060–72.
Dong Y, Lee SO, Zhang HT, Marshall J, Gao AC, Ip C. Prostate specific antigen expression is down-regulated by selenium through disruption of androgen receptor signaling. Cancer Res. 2004;64:19–22.
We are grateful to Dr. Stephen Plymate at the University of Washington for providing cumate-inducible AR-V7 expression construct. We appreciate the support from the Tulane Cancer Next Generation Sequence Analysis core for utilization of resources and expertise for this work.
Conflict of interest
This work was funded by grants from the Department of Defense (W81XWH-19-1-0363, W81XWH-17-1-0674), Prostate Cancer Foundation Challenge Award, Mimi and John Cole Foundation and Charles Y. Pak grant to GVR, from the National Institutes of Health (R01CA188609) and the Department of Defense (W81XWH-15-1-0439 and W81XWH-16-1-0317) to YD, and from the National Institutes of Health (R01 CA178338) to DG. The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding agencies.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Dedication: This paper is dedicated to the memory of Amy Rui Li, lab manager of the Raj laboratory, who lost her battle with cancer.
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Roggero, C.M., Jin, L., Cao, S. et al. A detailed characterization of stepwise activation of the androgen receptor variant 7 in prostate cancer cells. Oncogene 40, 1106–1117 (2021). https://doi.org/10.1038/s41388-020-01585-5