TPI1 Loss Triggers a Metabolite-Driven Mitochondrial Redox Vulnerability via the SARM1-cADPR-Ca²⁺ Axis

Cellular senescence is a stable cell cycle arrest program with important therapeutic implications in cancer, yet how metabolic perturbations are translated into redox-dependent senescence remains incompletely understood. Here, we identify triosephosphate isomerase 1 (TPI1) as a critical regulator of senescence in clear cell renal cell carcinoma (ccRCC) through a customized CRISPR-Cas9 metabolic screen. TPI1 depletion induces a robust senescence phenotype characterized by mitochondrial redox imbalance, DNA damage, and stable growth arrest. Mechanistically, loss of TPI1 leads to accumulation of dihydroxyacetone phosphate (DHAP), which engages a SARM1-dependent signaling pathway, resulting in increased cyclic ADP-ribose (cADPR) production and intracellular Ca²⁺ release. This cADPR-Ca²⁺ axis drives mitochondrial ROS (mtROS) generation, thereby promoting DNA damage and activation of the p53-p21 pathway to enforce senescence. Pharmacological or genetic attenuation of calcium signaling, or mitochondrial ROS partially rescues these phenotypes, indicating that calcium-dependent redox stress is required for senescence induction. Importantly, this metabolic-redox signaling cascade is conserved across multiple cancer types. Collectively, our findings define a previously unrecognized TPI1-SARM1-cADPR-Ca²⁺ axis that links glycolytic metabolite accumulation to mitochondrial redox stress and cellular senescence, highlighting a metabolite-driven redox vulnerability that may be therapeutically exploitable in cancer.