CircPKN2 Promotes Ferroptosis in Bladder Cancer by Promoting the Ubiquitination of Stearoyl-CoA Desaturase 1

Bladder cancer (BC) is one of the most common malignancies in the male urinary system and currently lacks an optimal treatment strategy. To elucidate the pathogenic mechanisms of BC from the perspective of circular RNAs, we conducted this study. Building upon our previous research, a novel circRNA, circPKN2, captured our interest due to its significant downregulation in BC, and its close association with the prognosis of BC patients. Our research findings indicate that circPKN2 can inhibit the proliferation and migration of BC cells in vitro. Furthermore, we discovered that circPKN2 exerts its anti-cancer effects in BC by promoting ferroptosis. Mechanistic studies revealed that circPKN2 recruits STUB1 to facilitate the ubiquitination of SCD1, thereby suppressing the WNT pathway and promoting ferroptosis in BC. Additionally, our research unveiled the regulatory role of the splicing factor QKI in the biogenesis of circPKN2. Animal studies demonstrated that circPKN2 enhances ferroptosis in BC cells in vivo, inhibiting tumor growth and metastasis. The discovery of the anti-cancer factor circPKN2 holds promise for providing new therapeutic targets in the prevention and treatment of BC.