DARS2 Promotes Bladder Cancer Progression by Enhancing PINK1-Mediated Mitophagy

Background: Bladder cancer is the tenth most common cancer worldwide. Mitochondria, as central hubs of cellular metabolism, play a crucial role in various diseases and cancers. However, the role and underlying mechanisms of mitophagy, the key process governing mitochondrial quantity and quality control, remain unclear in bladder cancer. Methods: 824 mitophagy-related genes were collected from the Genecards database. Construction and validation of the mitophagy-related genes prognostic model were completed by univariate Cox analysis, Lasso and SuperPC algorithms, Kaplan-Meier survival, univariate and multifactorial Cox regression. The screening and intervention of DARS2 were done by univariate Cox regression, Monocle3 pseudotime and DepMap analysis as wel as siRNA and shRNA. Mitophagy was detected by flow cytometry analysis, super-resolution microscopy, confocal microscopy and transmission electron microscopy. Results: We screened 16 mitophagy-related genes to construct a prognostic model, which demonstrated strong predictive performance for overall survival, immune response, and chemotherapy outcomes in bladder cancer patients. Among these genes, DARS2 was identified as having a particularly significant impact on bladder cancer prognosis. Further investigation revealed that DARS2 promotes G1-to-S phase transition by upregulating CDK4 expression, thereby inhibiting cellular senescence and promoting cell proliferation. Additionally, DARS2 enhanced PINK1 expression in bladder cancer cells, leading to increased PINK1-mediated mitophagy. Importantly, both in vitro and in vivo experiments confirmed that DARS2 inhibits cellular senescence and promotes tumor progression by enhancing PINK1-mediated mitophagy. Conclusions: DARS2 promotes PINK1-mediated mitophagy and facilitates G1-to-S phase transition, thereby delaying cellular senescence and promoting bladder cancer progression. Targeting DARS2 and mitophagy could be a promising therapeutic strategy to improve the prognosis of bladder cancer patients.