【摘要】 目的：探讨乳酸对三阴性乳腺癌（triple-negative breast cancer,TNBC）细胞恶性行为的影响，并揭示胰岛素样生长因子2 mRNA结合蛋白3(insulin-like growth factor 2 m RNA binding protein 3,IGF2BP3)通过m6A依赖性方式调控EP300，进而介导代谢重编程的表观遗传学机制。方法：通过外源性添加乳酸钠处理TNBC细胞，采用CCK-8、集落形成、划痕愈合和Transwell实验检测细胞增殖与迁移能力；利用shRNA慢病毒载体构建IGF2BP3稳定敲低细胞模型，结合Western blot分析组蛋白乳酸化修饰水平；进一步通过RIP-seq、MeRIP-seq筛选IGF2BP3的m6A靶基因，并利用qRT-PCR和Western blot验证关键分子表达。结果：乳酸钠处理显著增强了TNBC细胞的增殖和迁移能力，且泛乳酸化水平随乳酸浓度梯度升高而增加。IGF2BP3敲低可降低组蛋白乳酸化修饰水平。通过整合RIP-seq和MeRIP-seq数据，鉴定出699个其转录本同时被IGF2BP3特异性结合且携带m6A修饰的候选基因，这些基因显著富集于表观遗传调控和代谢相关通路。EP300转录本上IGF2BP3的结合区域与m6A修饰位点高度重合，且EP300的表达水平在IGF2BP3敲低后明显下调。结论：外源性乳酸通过泛乳酸化修饰促进TNBC的恶性进展。IGF2BP3通过m6A依赖性机制调控EP300的表达，进而介导组蛋白乳酸化修饰与代谢重编程的协同作用，最终驱动TNBC的肿瘤进展。上述发现为靶向代谢-表观遗传交互调控的新型治疗策略提供了理论依据。更多还原

【Abstract】 Objective:To investigate the functional impact of lactate on triple-negative breast cancer(TNBC)malignancy and elucidate an m6A-dependent epigenetic mechanism through which insulin-like growth factor 2 mRNA-binding protein 3(IGF2BP3)orchestrates metabolic reprogramming via regulation of EP300. Methods:TNBC cells were treated with exogenous sodium lactate supplementation to investigate their oncogenic effects. Cell proliferation and migration were assessed via CCK-8,colony formation,wound healing,and Transwell assays. Stable IGF2BP3-knockdown cell models were established using shRNA lentiviral vectors,with histone lactylation modification levels analyzed by Western blot. RNA immunoprecipitation sequencing(RIP-seq)and m6A-specific methylated RNA immunoprecipitation sequencing(MeRIP-seq)were used to identify IGF2BP3’s m6A target genes,validated by qRTPCR and Western blot for key molecule expression. Results:Sodium lactate treatment significantly enhanced TNBC cell proliferation and migration,with pan-lactylation levels increasing dose-dependently. IGF2BP3 knockdown reduced histone lactylation. Integrated RIP-seq/MeRIP-seq analysis identified 699 candidate genes whose transcripts bore both IGF2BP3-specific binding and m6A modifications,significantly enriched in epigenetic regulation and metabolic pathways. IGF2BP3-binding regions on EP300 transcripts overlapped extensively with m6A sites,and EP300 expression was markedly downregulated post-IGF2BP3 knockdown. Conclusion:Exogenous lactate drives TNBC malignant progression by orchestrating pan-lactylation modifications. IGF2BP3 regulates EP300expression through m6A-dependent mechanisms,mediating the synergistic interplay between histone lactylation and metabolic reprogramming to drive TNBC progression. These findings provide a theoretical basis for novel therapeutic strategies targeting metabolism-epigenetics crosstalk.更多还原