High-fat diet activates TPI1 lactylation to promote colorectal tumorigenesis by redirecting phospholipid synthesis toward glycolysis

High-fat diet (HFD) is known to promote colorectal cancer (CRC) tumorigenicity. Lactate-induced protein lysine lactylation plays a critical role in the progression of malignancies; however, its significance in HFD-driven cancer remains unclear. Here, using a genetically engineered mouse model, we observe enhanced glycolytic metabolism and elevated levels of lactylation in HFD-driven CRC. By performing a screen of the lactylated proteome, we identify that triosephosphate isomerase (TPI1) undergoes lactylation at lysine residues 142 and 188. This lactylation enhances TPI1’s activity to convert dihydroxyacetone phosphate to glyceraldehyde 3-phosphate via conformational changes, thereby directing phospholipid synthesis toward glycolysis in cancer cells. This metabolic rewiring contributes to HFD-induced CRC tumorigenesis. Moreover, the interaction between TPI1 and aldolase A (ALDOA), which is strengthened by TPI1 lactylation, facilitates glycolysis in HFD-associated CRC. Cell-penetrating peptides designed to competitively inhibit TPI1 lactylation effectively suppress HFD-related CRC progression. Clinically, TPI1 lactylation correlates with poor prognosis in obese patients with CRC. Thus, TPI1 lactylation serves as a key signal coordinating lipid and glucose metabolism, and may represent a therapeutic target for HFD-driven cancer.