DNA repair by nonhomologous end joining and homologous recombination during cell cycle in human cells.
DNA repair by nonhomologous end joining and homologous recombination during cell cycle in human cells.
复制标题
DOI：
10.4161/cc.7.18.6679
复制
发表时间：
2008-09-15
期刊：
影响因子：
--
通讯作者：
Gorbunova V
中科院分区：
文献类型：
--
作者：
Mao Z;Bozzella M;Seluanov A;Gorbunova V
DNA双链断裂（DSB）是一种危险的病变，可导致潜在的致癌基因组重排或细胞死亡。DSB修复的两个主要途径是非同源末端连接（NHEJ）和同源重组（HR）。NHEJ是一种固有的易错途径，而HR导致准确的修复。为了了解人类细胞中基因组不稳定性的起源，重要的是要知道每个DSB修复途径的贡献。对啮齿动物细胞和人类癌细胞系的研究表明，NHEJ或HR途径之间的选择取决于细胞周期阶段。令人惊讶的是，DSB修复的细胞周期调控尚未在具有完整细胞周期检查点的正常人细胞中进行检查。在这里，我们测量了在hTERT永生化的二倍体人成纤维细胞的不同细胞周期阶段的NHEJ和HR的效率。我们利用具有染色体整合的荧光报告盒的细胞，其中通过稀有切割核酸内切酶引入独特的DSB。我们发现，NHEJ在整个细胞周期中是活跃的，并且其活性随着细胞从G1到G2/M（G1<S<G2/M）的进展而增加。HR在G1期几乎不存在，在S期最活跃，在G2/M期下降。因此，在G2/M中，NHEJ升高，而HR下降。这与一般认为NHEJ在G1中最活跃，而HR在S，G2和M中最活跃相反。在所有细胞周期阶段，NHEJ的总体效率均高于HR。我们的结论是，人类体细胞利用易错NHEJ作为主要的DSB修复途径在所有细胞周期阶段，而HR主要用于S期。
DNA double-strand breaks (DSBs) are dangerous lesions that can lead to potentially oncogenic genomic rearrangements or cell death. The two major pathways for repair of DSBs are nonhomologous end joining (NHEJ) and homologous recombination (HR). NHEJ is an intrinsically error-prone pathway while HR results in accurate repair. To understand the origin of genomic instability in human cells it is important to know the contribution of each DSB repair pathway. Studies of rodent cells and human cancer cell lines have shown that the choice between NHEJ or HR pathways depends on cell cycle stage. Surprisingly, cell cycle regulation of DSB repair has not been examined in normal human cells with intact cell cycle checkpoints. Here we measured the efficiency of NHEJ and HR at different cell cycle stages in hTERT-immortalized diploid human fibroblasts. We utilized cells with chromosomally-integrated fluorescent reporter cassettes, in which a unique DSB is introduced by a rare-cutting endonuclease. We show that NHEJ is active throughout the cell cycle, and its activity increases as cells progress from G1 to G2/M (G1<S<G2/M). HR is nearly absent in G1, most active in the S phase, and declines in G2/M. Thus, in G2/M NHEJ is elevated, while HR is on decline. This is in contrast to a general belief that NHEJ is most active in G1, while HR is active in S, G2 and M. The overall efficiency of NHEJ was higher than HR at all cell cycle stages. We conclude that human somatic cells utilize error-prone NHEJ as the major DSB repair pathway at all cell cycle stages, while HR is used, primarily, in the S phase.
登录
查看更多内容
影响因子：
10.5
作者：
Ferreira, MG;Cooper, JP
通讯作者：
Cooper, JP
影响因子：
10.5
作者：
Mills, KD;Ferguson, DO;Alt, FW
通讯作者：
Alt, FW
影响因子：
3.8
作者：
Sonoda, Eiichiro;Hochegger, Helfrid;Takeda, Shunichi
通讯作者：
Takeda, Shunichi
DOI：
10.1016/0921-8777(94)90063-9
发表时间：
1994-01-01
期刊：
MUTATION RESEARCH
影响因子：
--
作者：
CHEONG, N;WANG, XM;ILIAKIS, G
通讯作者：
ILIAKIS, G
DOI：
10.1073/pnas.0400726101
发表时间：
2004-05-18
影响因子：
11.1
作者：
Seluanov, A;Mittelman, D;Gorbunova, V
通讯作者：
Gorbunova, V