Genome-scale CRISPR screens identify PTGES3 as a direct modulator of AR function in advanced prostate cancer

ABSTRACT: The androgen receptor (AR) is a critical driver of prostate cancer (PCa). To study regulators of AR protein levels and oncogenic activity, we created the first live cell quantitative endogenous AR fluorescent reporters. Leveraging this novel AR reporter, we performed genome-scale CRISPRi flow cytometry sorting screens to systematically identify genes that modulate AR protein levels. We identified and validated known AR protein regulators including HOXB13 and GATA2 and also unexpected top hits including PTGES3, a poorly characterized gene in PCa. PTGES3 repression resulted in loss of AR protein, cell cycle arrest, and cell death in AR-driven PCa models. PTGES3 is not a commonly essential gene, and our data nominate it as a prime PCa drug target. Clinically, analysis of PCa data demonstrate that PTGES3 expression is associated with AR directed therapy resistance. Mechanistically, we show PTGES3 binds directly to AR, forms a protein complex with AR in the nucleus, regulates AR protein stability in vitro and in vivo and modulates AR function in the nucleus at AR target genes. Lastly using a disulfide tethering fragment screen, we developed a PTGES3 covalent inhibitor that blocks the PTGES3/AR interaction and represses AR signaling in PCa cells, suggesting PTGES3 inhibitors may be a next generation AR-targeting therapeutic strategy that can overcome known mechanisms of resistance to existing AR-directed therapies in PCa.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Cell Culture

SUBMITTER: Abhilash Barpanda  

LAB HEAD: Arun Wiita

PROVIDER: PXD066297 | Pride | 2025-08-08

REPOSITORIES: Pride