Glycogen stores mediated by the p53-GYS1 feedback circuit engenders platinum resistance in ovarian clear cell carcinoma

Abstract

Ovarian cancer (OC) is a highly fatal and refractory malignancy affecting women, and platinum resistance remains a major clinical dilemma. Compared with other OC subtypes, ovarian clear cell carcinoma (OCCC) frequently exhibits increased platinum refractoriness, accompanied by increased glycogen levels, which promotes clear-cell morphology, and wild-type p53. However, the roles of these factors in platinum resistance of OCCC are unclear. Here, we investigated whether glycogen promotes OCCC resistance to platinum agents and reported that GYS1, a rate-limiting enzyme in glycogen synthesis, is clinically associated with poor prognosis and chemoresistance in OCCC. Mechanistically, p53 promotes GYS1 breakdown via the upregulation of RNF144a, whereas GYS1 induces the reversal of p53 ubiquitination and degradation by competitively binding to USP14, forming a positive feedback circuit. Under platinum stress, the accumulated glycogen is mobilized by the p53/GYS1 feedback circuit, which fuels energetic NADPH production, resulting in resistance to disulfidptosis and increased platinum resistance in OCCC. Collectively, our findings identify glycogen as a contributor to OCCC platinum resistance and elucidate the underlying mechanisms, highlighting a crucial p53/GYS1 positive feedback loop.