DNA2和FANCM在破坏TERRA R循环和抑制ALT端粒的复制应激方面通过两个不同的途径发挥作用
bioRxiv : the preprint server for biology
|June 6, 2025
概括
在替代延长端粒 (ALT) 癌症中不激活DNA2会增加复制压力和DNA损伤. 同时准DNA2和FANCM显示ALT+细胞的合成致死性,提供了一种新的癌症治疗策略.
科学领域:
- 分子生物学分子生物学
- 癌症研究 癌症研究
- 遗传学 遗传学 是一个
背景情况:
- 癌症利用端粒维持机制 (TMM) 维持生存,主要是端粒酶 (85-90%) 或替代端粒延长 (ALT) 途径 (10-15%).
- 众所周知,FANCM通过破坏TERRA R环来抑制ALT端粒的复制应激和DNA损伤.
研究的目的:
- 研究DNA2在ALT端粒维护中的作用.
- 探索针对ALT阳性癌症的DNA2和FANCM的治疗潜力.
主要方法:
- 在ALT阳性 (ALT+) 和端粒酶阳性 (TEL+) 细胞中DNA2的失活.
- 对复制应激,DNA损伤和ALT特性 (TIF,APB,C圆) 的评估.
- 通过光学映射 (SMTA-OM) 分析TERRA R环,复制效率和基因相互作用,使用共耗尽和单分子端粒测定.
主要成果:
- 在ALT+细胞中DNA2无活化,但不是TEL+细胞,显著增加复制应激,DNA损伤,TERRA R循环和ALT特性.
- DNA2和FANCM的同时减少导致了合成致死性,特别是在ALT+细胞中.
- SMTA-OM揭示了DNA2或FANCM缺乏细胞中的全基因组端粒长度增加和染色体臂特定的端粒变化.
结论:
- DNA2在抑制复制应激和保持ALT+细胞中端粒完整性方面发挥着至关重要的作用.
- 在共同向DNA2和FANCM时观察到的合成致命性为ALT+癌症提供了一个有前途的治疗策略.
- 不同染色体臂的端粒对复制应激表现出不同的反应,突出显示了端粒维护的复杂性.
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