ENO1 lactylation drives bevacizumab resistance through metabolic reprogramming and angiogenesis in ovarian cancer.

Bevacizumab, a monoclonal antibody targeting Vascular Endothelial Growth Factor (VEGF), is a cornerstone therapy for ovarian cancer (OC). However, acquired resistance to bevacizumab remains a major clinical challenge. Metabolic reprogramming in the tumor microenvironment, particularly lactate-driven lactylation modifications, has been implicated in drug resistance; however, the specific mechanisms underlying bevacizumab resistance are poorly understood. This study identifies Enolase 1 (ENO1) lactylation as a key driver of drug resistance through the integration of lactylation proteomics in patient samples, functional validation in cell lines and in vivo models Patient-Derived Xenograft (PDX), zebrafish, and chicken Chorioallantoic Membrane (CAM)). We observed significantly elevated pan-lactylation in bevacizumab-resistant OC tissues, correlating with enhanced angiogenesis and poor prognosis. Mechanistically, alanyl-tRNA synthetase 1 (AARS1) mediated lactylation of ENO1 at lysine 71 (K71) augmented lactate synthesis and promoted histone lactylation marks (Lysine lactylation of histone H3 at lysine 9 (H3K9la) and Lysine Lactylation of Histone H3 at Lysine 14 (H3K14la)). This epigenetic reprogramming upregulated the transcription of the angiogenic factor Endothelial cell-specific molecule 1 (ESM1), establishing a positive feedback loop for ENO1 expression. Secreted ESM1 stabilized the transcription factor YY1 in endothelial cells by competitively inhibiting Smurf2-mediated ubiquitination, leading to YY1-dependent recruitment of E1A Binding Protein p300 (EP300) and Histone H3 Lysine 27 (H3K27) acetylation at the B-cell lymphoma 2-related protein A1 (BCL2A1) promoter. This cascade enhanced endothelial cell survival and angiogenesis, ultimately fostering resistance to bevacizumab. Our findings reveal a metabolic-epigenetic axis centered on ENO1 K71 lactylation that perpetuates resistance to bevacizumab, highlighting its potential as a therapeutic target to restore bevacizumab efficacy in OC.