Oxaliplatin-based therapeutics is a widely used treatment approach for hepatocellular carcinoma (HCC) patients; however, drug resistance poses a significant clinical challenge. Epigenetic modifications have been implicated in the development of drug resistance. In our study, employing siRNA library screening, we identified that silencing the m⁶A writer METTL3 significantly enhanced the sensitivity to oxaliplatin in both in vivo and in vitro HCC models. Further investigations through combined RNA-seq and non-targeted metabolomics analysis revealed that silencing METTL3 impeded the pentose phosphate pathway (PPP), leading to a reduction in NADPH and nucleotide precursors. This disruption induced DNA damage, decreased DNA synthesis, and ultimately resulted in cell cycle arrest. Mechanistically, METTL3 was found to modify E3 ligase TRIM21 near the 3’UTR with N⁶-methyladenosine, leading to reduced RNA stability upon recognition by YTHDF2. TRIM21, in turn, facilitated the degradation of the rate-limiting enzyme of PPP, G6PD, through the ubiquitination-proteasome pathway. Importantly, high expression of METTL3 was significantly associated with adverse prognosis and oxaliplatin resistance in HCC patients. Notably, treatment with the specific METTL3 inhibitor, STM2457, significantly improved the efficacy of oxaliplatin. These findings underscore the critical role of the METTL3/TRIM21/G6PD axis in driving oxaliplatin resistance and present a promising strategy to overcome chemoresistance in HCC.

基于奥沙利铂的疗法是肝细胞癌 （HCC） 患者广泛使用的治疗方法;然而，耐药性带来了重大的临床挑战。表观遗传修饰与耐药性的发展有关。在我们的研究中，采用 siRNA 文库筛选，我们发现沉默 m⁶A 写入器 METTL3 显着增强了体内和体外 HCC 模型中对奥沙利铂的敏感性。通过结合 RNA-seq 和非靶向代谢组学分析的进一步研究表明，沉默 METTL3 阻碍了磷酸戊糖途径 （PPP），导致 NADPH 和核苷酸前体减少。这种破坏诱导了 DNA 损伤，减少了 DNA 合成，并最终导致细胞周期停滞。从机制上讲，发现 METTL3 用 N⁶-甲基腺苷修饰 3'UTR 附近的 E3 连接酶 TRIM21，导致 YTHDF2 识别后 RNA 稳定性降低。反过来，TRIM21 通过泛素化-蛋白酶体途径促进了 PPP 限速酶 G6PD 的降解。重要的是，METTL3 的高表达与 HCC 患者的不良预后和奥沙利铂耐药显著相关。值得注意的是，用特异性 METTL3 抑制剂 STM2457 治疗显着提高了奥沙利铂的疗效。这些发现强调了 METTL3/TRIM21/G6PD 轴在驱动奥沙利铂耐药中的关键作用，并提出了一种有前途的克服 HCC 化疗耐药的策略。