脂肪质量和肥胖相关蛋白FTO是一种最常见的mRNA修饰N6-甲基腺嘌呤的“橡皮擦”。FTO在肿瘤发生中扮演重要角色。然而，它的活动尚未完全阐明，它可能与DNA损伤（肿瘤发生的早期驱动因素）的可能涉及程度仍不明确。在这里，我们调查了FTO在DNA损伤响应（DDR）和其潜在机制中的角色。我们证明了FTO对各种DNA损伤刺激作出反应。在接触致突变物质马兜铃酸I和苯并芘后，小鼠中FTO的表达增加。通过CRISPR/Cas9将FTO基因敲除在TK6细胞中，因DNA损伤刺激增加了基因毒性（微核和TK突变检测）。FTO KO细胞中顺铂和双环丁烷诱导的微核频率和甲基甲烷磺酸酯和硫醇异烟肼诱导的TK突变频率也更高。我们调查了FTO在DDR中的潜在作用。RNA测序和富集分析显示，FTO的缺失破坏了p38 MAPK路径，并抑制了核苷酸切除修复和与细胞周期相关的通路在顺铂（DNA链内交联）治疗后的激活。这些效应经过western blotting和qRT-PCR确认。FTO缺失削弱了细胞在顺铂和双环丁烷处理后G2/M期的细胞周期阻滞（流式细胞术分析）。我们的发现表明，FTO在DDR的几个方面中发挥作用，至少部分地通过妨碍细胞周期进展。版权所有 ©2023 Elsevier B.V.。保留所有权利。

The fat mass and obesity-associated protein FTO is an "eraser" of N6-methyladenosine, the most abundant mRNA modification. FTO plays important roles in tumorigenesis. However, its activities have not been fully elucidated and its possible involvement in DNA damage - the early driving event in tumorigenesis - remains poorly characterized. Here, we have investigated the role of FTO in the DNA damage response (DDR) and its underlying mechanisms. We demonstrate that FTO responds to various DNA damage stimuli. FTO is overexpressed in mice following exposure to the promutagens aristolochic acid I and benzo[a]pyrene. Knockout of the FTO gene in TK6 cells, via CRISPR/Cas9, increased genotoxicity induced by DNA damage stimuli (micronucleus and TK mutation assays). Cisplatin- and diepoxybutane-induced micronucleus frequencies and methyl methanesulfonate- and azathioprine-induced TK mutant frequencies were also higher in FTO KO cells. We investigated the potential roles of FTO in DDR. RNA sequencing and enrichment analysis revealed that FTO deletion disrupted the p38 MAPK pathway and inhibited the activation of nucleotide excision repair and cell-cycle-related pathways following cisplatin (DNA intrastrand cross-links) treatment. These effects were confirmed by western blotting and qRT-PCR. FTO deletion impaired cell-cycle arrest at the G2/M phase following cisplatin and diepoxybutane treatment (flow cytometry analysis). Our findings demonstrated that FTO is involved in several aspects of DDR, acting, at least in part, by impairing cell cycle progression.Copyright © 2023 Elsevier B.V. All rights reserved.