文章：

RRM1 O-GlcNAc糖基化抑制通过TK1介导的复制应激抑制胰腺癌

RRM1 O-GlcNAcylation inhibition suppresses pancreatic cancer via TK1-mediated replication stress 

原文发布日期：2025-03-28

英文摘要：

O-GlcNAcylation of ribonucleotide reductase large subunit M1 (RRM1) at position 734 influences high glucose-induced genomic instability and cell transformation in normal pancreatic cells. By disrupting the ribonucleotide reductase complex, it reduces dNTPs. Although the impact of RRM1 O-GlcNAcylation on pancreatic cancer progression remains unexplored, our CRISPR knock-in technology created the RRM1-T734A mutation to minimize RRM1 O-GlcNAcylation. In pancreatic cancer PANC-1 cells with this mutation, we observed heightened replication stress-induced DNA damage, S-phase delays, and diminished in vitro tumor cell growth. Mechanistically, RRM1-T734A enhanced its interaction with RRM2 while impairing binding to RRM2B, leading to decreased NTPs and disrupted dNTP equilibrium. Notably, it doubled dTTP levels via TK1 stabilization mediated by thymidine, resulting in S-phase delay. TK1 silencing restored RRM1-T734A-induced effects on S-phase retardation and decreased colony formation. Our findings highlight the pivotal role of O-GlcNAcylation of RRM1 at T734 in maintaining genomic stability and promoting pancreatic cancer malignancy. Furthermore, reducing RRM1 O-GlcNAcylation increased pancreatic cancer cell sensitivity to gemcitabine, proposing a potential therapeutic strategy. 

摘要翻译：

核糖核苷酸还原酶大亚基M1（RRM1）第734位的O-GlcNAc糖基化修饰影响高糖诱导的正常胰腺细胞基因组不稳定性和细胞转化。该修饰通过破坏核糖核苷酸还原酶复合体降低dNTPs水平。尽管RRM1 O-GlcNAc修饰对胰腺癌进展的影响尚未明确，我们利用CRISPR基因敲入技术构建了RRM1-T734A突变体以最小化其O-GlcNAc修饰。在携带该突变的胰腺癌PANC-1细胞中，我们观察到复制应激诱导的DNA损伤增强、S期阻滞以及体外肿瘤细胞生长减弱。机制上，RRM1-T734A突变增强了与RRM2的相互作用，但削弱了与RRM2B的结合，导致NTPs减少和dNTP平衡破坏。值得注意的是，该突变通过胸苷介导的TK1稳定性使dTTP水平翻倍，进而引发S期延迟。沉默TK1可逆转RRM1-T734A突变诱导的S期阻滞效应并恢复集落形成能力。我们的研究揭示了RRM1 T734位点O-GlcNAc修饰在维持基因组稳定性和促进胰腺癌恶性进展中的关键作用。此外，降低RRM1 O-GlcNAc修饰可增强胰腺癌细胞对吉西他滨的敏感性，这为治疗策略提供了新方向。

原文链接：

RRM1 O-GlcNAcylation inhibition suppresses pancreatic cancer via TK1-mediated replication stress