Metabolic Reprogramming-Driven Lactylation: Emerging Mechanisms Linking DNA Damage Repair and Chemoresistance in Cancer

Lactylation is an emerging lactate-derived post-translational modification that may link tumour metabolic reprogramming, epigenetic regulation and DNA damage repair. Enhanced glycolysis and lactate accumulation are common in many tumours, and lactate has been reported to induce histone and non-histone lactylation in specific experimental contexts. Recent studies suggest that lactylation is associated with several DNA repair pathways, including base excision repair/single-strand break repair, nucleotide excision repair, homologous recombination and non-homologous end joining, and may contribute to therapy resistance in selected cancer models. Specifically, XRCC1 lactylation has been reported to promote nuclear translocation and repair activity in glioblastoma models; H4K12 lactylation has been linked to PARP inhibitor resistance through RAD23A activation in ovarian cancer models; and BLM lactylation has been associated with enhanced homologous recombination repair in bladder cancer models. Lactylation of NBS1, RAD51 and XLF has also been implicated in DNA repair regulation in specific experimental systems, although some mechanistic links are inferred from pathway activation or functional rescue experiments rather than directly demonstrated across multiple tumour types. These findings suggest that lactylation may modulate DNA repair and therapeutic response in a context-dependent manner. Targeting lactate metabolism, transport and lactylation regulators, including LDHA, MCT1/4, ACAT1, AARS1 and GCN5, or using site-specific lactylation-inhibiting peptides may improve chemotherapy and PARP inhibitor efficacy, but clinical translation remains limited by heterogeneity, metabolic plasticity, toxicity and insufficient validation.