A positive feedback loop of OTUD1 and c-Jun driven by leptin expedites stemness maintenance in ovarian cancer

Cancer stem cells (CSCs) are closely associated with drug resistance and recurrence in ovarian cancer patients. Although leptin is a high-risk factor for ovarian cancer and promotes stemness maintenance, a therapeutic strategy that counteracts the downstream signaling pathway of leptin remains elusive. Herein, the deubiquitinase OTUD1 was identified as a critical regulator of leptin in maintaining OCSCs properties. Mechanistically, leptin treatment significantly increased the chromatin enrichment of the transcription factor c-Jun, including the OTUD1 gene enhancer, which was sufficient to increase the OTUD1 protein level and subsequently cause OTUD1 aggresome formation, ASK1 recruitment and JNK/c-Jun pathway activation. The resultant positive feedback loop of c-Jun and OTUD1 was required for OCSCs stemness maintenance. Notably, the disruption of the positive feedback loop by targeting c-Jun or ASK1/JNK with T-5224, selonsertib, or ibrutinib markedly inhibited the leptin-induced stemness maintenance of OCSCs and tumorigenicity. Our findings reveal a crucial mechanism for leptin-mediated stemness maintenance and indicate that targeting c-Jun or the identified positive feedback loop has translational potential for ovarian cancer patients.