High-glucose-associated YTHDC1 lactylation reduces the sensitivity of bladder cancer to enfortumab vedotin therapy.

Hyperglycemia is a recognized risk factor for bladder cancer (BC). Enfortumab vedotin (EV), the first NECTIN4-targeting antibody-drug conjugate, demonstrates promising clinical efficacy in patients with advanced BC. In this study, we show that EV treatment is less effective in BC patients with diabetes than in those with normoglycemia. The subsequent in vitro and in vivo experiments indicate that high glucose decreases the sensitivity of BC cells to EV. Mechanistically, lactate overproduction associated with high glucose promotes AARS1-mediated YTHDC1 lactylation and enhances RNF183-mediated YTHDC1 ubiquitination. Downregulated YTHDC1 reduces JUND mRNA stability in an m6A-dependent manner, subsequently decreasing NECTIN4 expression and EV responsiveness. Our study identifies a high-glucose-associated lactate-AARS1-YTHDC1-JUND-NECTIN4 axis that affects EV sensitivity in BC. Targeting this axis with JUND activators or β-alanine may offer therapeutic strategies to enhance the sensitivity of BC cells to EV.