Targeting the WWP2-ASPP2 axis overcomes cisplatin resistance by inhibiting the mevalonate pathway in TP53-mutant bladder cancer.

Cisplatin resistance remains a major challenge in bladder cancer. Although the tumor suppressor ASPP2 is a critical co-factor for TP53-mediated apoptosis, its role in metabolic reprogramming and cisplatin response remains unclear. This study aimed to delineate the mechanism by which ASPP2 regulates cisplatin sensitivity through metabolic reprogramming. We first assessed the clinical significance of ASPP2 using patient tissues and public databases, finding that its downregulation in bladder cancer is associated with poor patient survival. Through gain- and loss-of-function studies in vitro and in vivo, we further demonstrated that ASPP2 inhibits the mevalonate (MVA) pathway independently of TP53 status, thereby sensitizing cells to cisplatin-induced DNA damage and apoptosis. This chemosensitizing effect was specifically reversed by the addition of MVA pathway metabolites. Moreover, WWP2 was identified as the E3 ubiquitin ligase responsible for ASPP2 degradation via K48-linked ubiquitination. Finally, WWP2 silencing was shown to stabilize ASPP2, suppress the MVA pathway, and synergize with cisplatin to impede tumor growth in mouse models. Overall, the WWP2-ASPP2-MVA pathway axis is identified as a novel driver of cisplatin resistance in bladder cancer. These results establish a mechanistic basis for targeting this axis to restore chemosensitivity, offering a promising therapeutic strategy for recalcitrant disease.