1. Constitutively active androgen receptor splice variants AR-V3, AR-V7 and AR-V9 are co-expressed in castration-resistant prostate cancer metastases.
- Author
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Kallio HML, Hieta R, Latonen L, Brofeldt A, Annala M, Kivinummi K, Tammela TL, Nykter M, Isaacs WB, Lilja HG, Bova GS, and Visakorpi T
- Subjects
- Androgens genetics, Cell Line, Tumor, DNA Copy Number Variations genetics, Gene Expression Regulation, Neoplastic genetics, Humans, Male, Neoplasm Metastasis, Prostate metabolism, Prostate pathology, Prostatic Hyperplasia pathology, Prostatic Hyperplasia surgery, Prostatic Neoplasms, Castration-Resistant pathology, Prostatic Neoplasms, Castration-Resistant surgery, RNA Splicing genetics, Exome Sequencing, Whole Genome Sequencing, Prostatic Hyperplasia genetics, Prostatic Neoplasms, Castration-Resistant genetics, Protein Isoforms genetics, Receptors, Androgen genetics
- Abstract
Background: A significant subset of prostate cancer (PC) patients with a castration-resistant form of the disease (CRPC) show primary resistance to androgen receptor (AR)-targeting drugs developed against CRPC. As one explanation could be the expression of constitutively active androgen receptor splice variants (AR-Vs), our current objectives were to study AR-Vs and other AR aberrations to better understand the emergence of CRPC., Methods: We analysed specimens from different stages of prostate cancer by next-generation sequencing and immunohistochemistry., Results: AR mutations and copy number variations were detected only in CRPC specimens. Genomic structural rearrangements of AR were observed in 5/30 metastatic CRPC patients, but they were not associated with expression of previously known AR-Vs. The predominant AR-Vs detected were AR-V3, AR-V7 and AR-V9, with the expression levels being significantly higher in CRPC cases compared to prostatectomy samples. Out of 25 CRPC metastases that expressed any AR variant, 17 cases harboured expression of all three of these AR-Vs. AR-V7 protein expression was highly heterogeneous and higher in CRPC compared to hormone-naïve tumours., Conclusions: AR-V3, AR-V7 and AR-V9 are co-expressed in CRPC metastases highlighting the fact that inhibiting AR function via regions common to all AR-Vs is likely to provide additional benefit to patients with CRPC.
- Published
- 2018
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