USP54 is a potential therapeutic target in castration-resistant prostate cancer

Abstract Background USP54, a ubiquitin-specific protease in the deubiquitinase (DUB) family, facilitates the malignant progression of several types of cancer. However, the role of USP54 in prostate cancer (PCa), especially castration-resistant prostate cancer (CRPC), remains unknown. Methods We established the CRPC LNCaP-AI cell line from the hormone-sensitive prostate cancer (HSPC) LNCaP cell line. RNA-Seq was utilized to explore DUB expression levels in LNCaP and LNCaP-AI. USP54 was knocked down, and its effects on cell growth were evaluated in vitro and in vivo. Bioinformatics analyses were conducted to explore signaling pathways affected by USP54 in PCa. Quantitative polymerase chain reaction was used to confirm key signaling pathways involved. Results USP54 was the most strongly upregulated DUB in LNCaP-AI cells compared with LNCaP cells. USP54 levels were higher in PCa than in normal tissues. USP54 silencing suppressed the proliferation of PCa cell lines, both in vitro and in vivo. USP54 expression was positively correlated with the androgen receptor (AR) signaling level in PCa samples, and USP54 knockdown inhibited AR signaling in PCa cells. Conclusions USP54 was upregulated during HSPC progression to CRPC. USP54 depletion suppressed CRPC cell proliferation both in vitro and in vivo. USP54 may facilitate PCa progression by regulating AR signaling.