Persistence of radiation-induced double-strand breaks in the DNA of heated CHO cells.
Persistence of radiation-induced double-strand breaks in the DNA of heated CHO cells.
复制标题
加热的 CHO 细胞 DNA 中辐射诱导的双链断裂持续存在。
DOI：
10.1080/09553009314551911
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发表时间：
1993
影响因子：
2.6
通讯作者：
Warters,RL
中科院分区：
文献类型：
--
作者：
Warters,RL
将中国仓鼠卵巢细胞在45°C下加热15分钟或在照射前立即不加热，并在37或41°C下孵育5小时。当细胞DNA进行分析，通过琼脂糖凝胶电泳的双链DNA照射后5小时，DNA片段可能导致未修复的DNA双链断裂（dsb）中观察到的所有细胞的DNA。与未加热的对照细胞相比，照射前在45°C下加热15分钟或照射后在41°C下孵育5小时的细胞中推定的未修复dsb的频率更高。凝胶电泳结果与照射前在45°C加热或照射后在41°C孵育5 h时照射细胞未能完全重新加入dsb一致。相比之下，使用外源性或内源性内切核酸酶的核DNA可及性研究检测到来自41° C加热的细胞的核中DNA的可及性没有变化。这些DNA可及性研究表明，在41° C加热细胞的DNA中观察到的dsb可能不是由于在41°C孵育期间辐照细胞修复辐射诱导dsb的实际失败所致。
Chinese hamster ovary cells were either heated at 45°C for 15 min or left unheated immediately prior to irradiation and incubation at 37 or 41°C for 5 h. When cellular DNA was analysed by electrophoresis of double-stranded DNA through agarose gels 5 h after irradiation, DNA fragments presumably resulting from unrepaired DNA double-strand breaks (dsbs) were observed in the DNA of all cells. The frequency of the putative unrepaired dsbs was greater in cells heated at 45°C for 15 min before, or incubated at 41°C for 5 h after irradiation, than in unheated, control cells. Gel electrophoresis results were consistent with a failure of irradiated cells to rejoin dsb completely when heated at 45°C before, or incubated at 41°C for 5 h after irradiation. In contrast, nuclear DNA accessibility studies using either an exogenous or an endogenous endonuclease detected no change in the accessibility of DNA in nuclei from 41°C-heated cells. These DNA accessibility studies indicate that the dsbs observed in the DNA of 41°C-heated cells may not result from an actual failure of irradiated cells to repair radiation-induced dsbs during incubation at 41°C.