在R环中的RNA m5C修改作为Alt-NHEJ的关闭开关
Haibo Yang1,2, Emily M Lachtara1,3, Xiaojuan Ran1,3,4
1Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA, USA.
Nature communications
|September 30, 2023
概括
DNA 损伤触发R-循环中的RNA m5C 修饰,影响DNA 修复路径的选择. 这一发现表明,向RNA m5C和DNA修复机制可能是一个新的癌症治疗策略.
科学领域:
- 分子生物学分子生物学
- 遗传学 遗传学 是一个
- 癌症研究 癌症研究
背景情况:
- 对于RNA修饰和R环在DNA双链断裂 (DSB) 修复中的作用尚不清楚.
- 了解这些机制对于开发向癌症疗法至关重要.
研究的目的:
- 研究DNA损伤反应期间R-循环中RNA甲基-5-细胞因子 (m5C) 修饰的功能.
- 确定m5C如何影响DSB修复路径选择和PARP1活动.
主要方法:
- 双硫酸盐测序用于全基因组R循环中的m5C修饰.
- 在体外和细胞测试以评估m5C对PARP1-介导的多ADP-核糖化 (PARylation) 的影响.
- 对DNA修复途径选择 (转录合同源复合与替代非同源末端结合) 的分析,以响应m5C水平.
主要成果:
- DNA损伤诱导R环中的m5C修饰,主要由甲基转移酶TRDMT1.1.
- 缺少m5C会导致增加R环相关的PARP1PARylation.
- m5C促进了转录合HR (TC-HR),同时抑制了替代非同类末端连接 (Alt-NHEJ),有利于转录区域中的TC-HR.
结论:
- 在R环中的RNA m5C修饰是DSB修复路径选择的关键调节者.
- 同时抑制TRDMT1和PARP或聚合酶 θ在癌细胞中表现出协同性细胞毒性.
- 针对R-loop m5C和替代DSB修复途径,通过利用基因组不稳定性,为癌症治疗提供了一个有希望的策略.
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