Kang Xing, Li Xinran, Zhou Jiaqi, Zhang Yang, Qiu Lingyu, Tian Congcong, Deng Zhiwen, Liang Xiaoyan, Zhang Ziwei, Du Songlin, Hu Suili, Wang Nan, Yue Zhen, Xu Yajing, Gao Yuan, Dai Junbiao, Wang Zhiquan, Yu Chuanhe, Chen Jinyi, Wu Yuchun, Chen Liangming, Yao Yuan, Yao Sitong, Yang Xinran, Yan Lixia, Wen Qing, Depies Olivia M, Chan Kuiming, Liang Xiaohuan, Li Gang, Zi Zhike, Liu Xiangyu, Gan Haiyun
Guangdong Provincial Key Laboratory of Synthetic Genomics, Key Laboratory of Quantitative Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
Guangdong Provincial Key Laboratory of Synthetic Genomics, Key Laboratory of Quantitative Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Cell. 2025 Apr 24. doi: 10.1016/j.cell.2025.04.012.
Extrachromosomal DNA (ecDNA) drives the evolution of cancer cells. However, the functional significance of ecDNA and the molecular components involved in its replication and maintenance remain largely unknown. Here, using CRISPR-C technology, we generated ecDNA-carrying (ecDNA+) cell models. By leveraging these models alongside other well-established systems, we demonstrated that ecDNA can replicate and be maintained in ecDNA+ cells. The replication of ecDNA activates the ataxia telangiectasia mutated (ATM)-mediated DNA damage response (DDR) pathway. Topoisomerases, such as TOP1 and TOP2B, play a role in ecDNA replication-induced DNA double-strand breaks (DSBs). A subset of these elevated DSBs persists into the mitotic phase and is primarily repaired by the alternative non-homologous end joining (alt-NHEJ) pathway, which involves POLθ and LIG3. Correspondingly, ecDNA maintenance requires DDR, and inhibiting DDR impairs the circularization of ecDNA. In summary, we demonstrate reciprocal interactions between ecDNA maintenance and DDR, providing new insights into the detection and treatment of ecDNA+ tumors.
染色体外DNA（ecDNA）驱动癌细胞的进化。然而，ecDNA的功能意义以及参与其复制和维持的分子成分在很大程度上仍不清楚。在这里，我们使用CRISPR-C技术生成了携带ecDNA（ecDNA+）的细胞模型。通过将这些模型与其他成熟的系统相结合，我们证明了ecDNA能够在ecDNA+细胞中复制并得以维持。ecDNA的复制激活了共济失调毛细血管扩张症突变（ATM）介导的DNA损伤反应（DDR）途径。拓扑异构酶，如TOP1和TOP2B，在ecDNA复制诱导的DNA双链断裂（DSB）中发挥作用。这些增加的DSB中的一部分持续到有丝分裂期，并主要通过涉及POLθ和LIG3的替代性非同源末端连接（alt-NHEJ）途径进行修复。相应地，ecDNA的维持需要DDR，抑制DDR会损害ecDNA的环化。总之，我们证明了ecDNA维持与DDR之间的相互作用，为ecDNA+肿瘤的检测和治疗提供了新的见解。
