The RNA helicase DDX17 enhances androgen receptor stability by interacting with the E3 ubiquitin ligase SPOP in prostate cancer.

Background: Prostate cancer (PCa) is a common malignancy in men, closely associated with androgen receptor (AR) signaling, and often diagnosed with elevated prostate-specific antigen (PSA). While androgen deprivation therapy (ADT) is effective, resistance develops due to reactivation of AR signaling, driving disease progression. We aimed to explore the role of DDX17 in the progression of PCa through its interaction with SPOP. We hypothesized that DDX17 can stabilize the AR by inhibiting SPOP-mediated ubiquitination, thereby maintaining AR signaling which supports tumor growth and survival. Methods: We collected gene expression data and clinical information from PCa patients from The Cancer Genome Atlas and Gene Expression Omnibus databases. Messenger RNA (mRNA) and protein levels were quantified using quantitative real-time polymerase chain reaction (PCR) and western blotting, respectively. Cell viability and invasion capabilities were assessed using cell counting kit-8 (CCK-8) and transwell invasion assays. The interactions between DDX17 and SPOP were examined through coimmunoprecipitation assays. Results: DDX17 exhibited high expression in both PCa tissues and cells. Silencing DDX17 led to reduced proliferation and invasion of PCa cells. Mechanistic investigations revealed that DDX17 directly interacted with SPOP, sustaining AR stability by preventing AR ubiquitination. These findings suggest a role of DDX17 in promoting the progression of PCa by binding and blocking SPOP ubiquitination of AR. Conclusions: This study elucidated a novel mechanism through which the RNA helicase DDX17 can promote PCa progression through its interaction with SPOP, thereby enhancing AR stability by inhibiting AR ubiquitination.