Abstract 2083: Alternative splicing regulation by the androgen receptor in prostate cancer cells

Abstract

Abstract The androgen receptor (AR) is a transcription factor that drives prostate cancer (PCa) by modulating the expression of thousands of genes to promote proliferation and survival and to reprogram metabolism. However, how AR activation affects alternative splicing is mostly unknown. Our objective was to define its role in the transcriptome-wide regulation of alternative splicing. Three human PCa models–LNCaP, LAPC4, and 22Rv1 cells–were treated with and without androgens, and RNA was purified for deep-sequencing analyses (RNA-seq). Several bio-informatic tools were then used to study alternative splicing. We demonstrate that in the absence of androgens, alternative splicing complexity is similar among AR-positive PCa cells, with 48% of all transcripts having various levels of alternative splicing. We also describe splicing differences among cell lines, such as specific splicing of AR, REST, TSC2, and CTBP1. Interestingly, AR activation changed the alternative splicing of thousands of transcripts in all the cell lines tested. Overlap between AR-sensitive alternative splicing events revealed that genes linked to PCa metabolism are major targets for this specific modulation. These genes encode metabolic enzymes such as the prostate-specific membrane antigen (FOLH1), malate dehydrogenase 1 (MDH1), and malic enzyme 2 (ME2). Enzymatic assays revealed that AR alters their activities without changing their total gene expression levels, demonstrating that AR-driven regulation of alternative splicing has a direct effect on cancer cell metabolism. Overall, our study presents a comprehensive analysis of PCa cell transcriptome and its modulation by AR, revealing cell metabolism as a key target for AR-dependent regulation of alternative splicing. Citation Format: Lucas Germain, Camille Lafront, Jolyane Beaudette, Raghavendra Tejo Karthik Poluri, Cindy Weidmann, Etienne Audet-Walsh. Alternative splicing regulation by the androgen receptor in prostate cancer cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2083.