DNA replication is required to elicit cellular responses to psoralen-induced DNA interstrand cross-links
DNA replication is required to elicit cellular responses to psoralen-induced DNA interstrand cross-links
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DOI：
10.1128/mcb.20.21.8283-8289.2000
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发表时间：
2000-11-01
影响因子：
5.3
通讯作者：
Grompe, M
中科院分区：
文献类型：
--
作者：
Akkari, YMN;Bateman, RL;Grompe, M
随着DNA链间交叉连接(ICL)的引入，哺乳动物细胞表现出染色体断裂或细胞周期延迟，DNA含量为4N。为了进一步了解延迟的性质，以前被描述为G(2)/M停滞，我们开发了一种协议，在细胞周期的特定间隔产生ICL。用光激活的4‘-羟甲基-4，5’，8-三甲基补骨脂素处理G(1)、S和G(2)细胞并计分进入有丝分裂的正常通道，与电离辐射不同，G(2)期间引入的ICL没有导致G(2)/M停滞、有丝分裂停滞或染色体断裂。相反，随后通过S时相需要触发下一个细胞周期中的染色体断裂和停滞。同样，在G(1)期间引入的ICL没有导致G(1)/S被捕。我们的结论是，在补骨脂素诱导的原代人成纤维细胞中，DNA复制是诱导细胞周期停滞和基因组不稳定所必需的。在原代人成纤维细胞中，由补骨脂素诱导的4N DNA含量细胞周期停滞是长期的，但是可逆的。动力学分析表明，这些细胞可以以11个ICL/基因组/小时的平均速度移除多达2500个ICL/基因组。
Following introduction of DNA interstrand cross-links (ICLs), mammalian cells display chromosome breakage or cell cycle delay with a 4N DNA content. To further understand the nature of the delay, previously described as a G(2)/M arrest, we developed a protocol to generate ICLs during specific intervals of the cell cycle. Synchronous populations of G(1), S, and G(2) cells were treated with photoactivated 4'-hydroxymethyl-4,5',8- trimethylpsoralen (HMT) and scored for normal passage into mitosis, In contrast to what was found for ionizing radiation, ICLs introduced during G(2) did not result in a G(2)/M arrest, mitotic arrest, or chromosome breakage. Rather, subsequent passage through S phase was required to trigger both chromosome breakage and arrest in the next cell cycle. Similarly, ICLs introduced during G(1) did not cause a G(1)/S arrest. We conclude that DNA replication is required to elicit the cellular responses of cell cycle arrest and genomic instability after psoralen-induced ICLs, In primary human fibroblasts, the 4N DNA content cell cycle arrest triggered by ICLs was long lasting but reversible. Kinetic analysis suggested that these cells could remove up to similar to 2,500 ICLs/genome at an average rate of 11 ICLs/genome/h.