AR and prostate cancer: This study investigated whether the immunoproteasome inhibitor ONX-0914 suppresses hormone-sensitive prostate cancer (HSPC) through metabolic modulation of AR and aimed to identify the transcriptional mediator involved.<h4>Methods</h4>HSPC and castration-resistant prostate cancer models were used to evaluate the effects of ONX-0914 on cell proliferation, invasion, migration, and epithelial-mesenchymal transition.