Abstract 1008: Comparative proteomics and transcriptomics analysis of the impact of androgen stimulation and darolutamide inhibition in a prostate cancer model
Authors: Nevedomskaya Ekaterina , Baumgart Simon J. , Sugawara Tatsuo , Lesche Ralf , Mumberg Dominik , Haendler Bernard 
Published: July 2021

Abstract
Androgen receptor (AR) signaling is the major driver in prostate cancer. Darolutamide is a high-affinity AR inhibitor recently approved for non-metastatic castration-resistant prostate cancer. The impact of the AR on gene transcription has been extensively examined but the downstream effects on protein levels are still poorly understood. Here we generated for the first time comprehensive quantitative proteomic and transcriptomic data from the androgen-sensitive, prostate cancer cell line VCaP treated with the androgen R1881 and darolutamide. For the proteomic analysis, a comprehensive and quantitative label-free protein expression profiling was performed using nanoscale liquid chromatography coupled to tandem mass spectrometry. For the transcriptomic analysis, sequencing was performed via single-end, 50 base-pair reads with an average depth of 21 million reads per sample. FASTQ reads were mapped with STAR aligner to the human genome GRCh38 and quantified with RSEM. Further analysis was performed in R statistical software. We investigated the expression levels of 12900 protein-coding genes and 8721 translated proteins. Androgen treatment resulted in increased expression of known androgen response genes, as well as of genes from the mTORC1 pathway, cell cycle and other pathways previously shown to be affected by androgens. This was paralleled by upregulation of the corresponding protein levels in the majority of cases. Importantly, a detailed comparative analysis of transcriptomic and proteomic data revealed a few notable differences in regulation. In androgen-treated prostate cancer cells, there was a strong increase of FOLH1, AMACR and FKBP5 transcript levels (10 to 40-fold) but only a moderate increase of the corresponding protein levels (2 to 6-fold). Additional darolutamide treatment led to strong down-regulation of androgen-induced gene expression and of the corresponding protein levels. Here also there were a few instances where protein and transcript levels were differentially regulated. The discrepancy in transcript and protein levels seen after androgen and anti-androgen treatment suggests differential post-transcriptional regulation of protein abundance to occur in some instances. In conclusion, we found that darolutamide strongly reversed androgen-induced activation of gene expression programs related to cell proliferation and survival, both at the transcript and protein levels. We furthermore identified for the first time androgen-activated genes whose function is additionally regulated at the post-transcription level.
Citation Format: Ekaterina Nevedomskaya, Simon J. Baumgart, Tatsuo Sugawara, Ralf Lesche, Dominik Mumberg, Bernard Haendler. Comparative proteomics and transcriptomics analysis of the impact of androgen stimulation and darolutamide inhibition in a prostate cancer model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1008.