Repair of DNA strand breaks at hyperthermic temperatures in Chinese hamster ovary cells.
Repair of DNA strand breaks at hyperthermic temperatures in Chinese hamster ovary cells.
复制标题
中国仓鼠卵巢细胞高温下 DNA 链断裂的修复。
DOI：
10.1080/09553009214550601
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发表时间：
1992
影响因子：
2.6
通讯作者：
Axtell,J
中科院分区：
文献类型：
--
作者：
Warters,RL;Axtell,J
DNA双链断裂的修复通过在X-照射之前或之后在25-45°C下孵育的细胞中的pH 7·2过滤洗脱来测量。在X射线照射之前立即暴露于45°C 15分钟显著增加了DNA双链断裂闭合的半衰期和照射后180分钟保留在核DNA中的DNA双链断裂的数量。在X射线照射后立即暴露于41 ° C至45°C之间的温度加速了DNA双链断裂闭合，并且在照射后180分钟，细胞基因组中剩余的DNA双链断裂数量没有增加。结果表明，照射前后给予高温所产生的放射增敏作用是由两种特征性不同的分子机制引起的，或者照射后核DNA中剩余的DNA链断裂闭合速率和DNA链断裂数量都不能准确预测高温放射增敏作用。这些结论假设没有DNA链断裂低于该DNA损伤测定的分辨率，并且暴露于高辐射剂量后细胞毒性和DNA修复之间的比较是有效的。
The repair of DNA double-strand breaks was measured by pH 7·2 filter elution in cells incubated at 25–45°C either before or after X-irradiation. Exposure to 45°C for 15 minutes immediately prior to X-irradiation significantly increased both the half-time for DNA double-strand break closure and the number of of DNA double-strand breaks remaining in nuclear DNA 180 minutes after irradiation. Exposure to temperatures between 41 and 45°C immediately after X-irradiation accelerated DNA double-strand break closure and resulted in no increase in the number of DNA double-strand breaks remaining in the cell's genome 180 minutes after irradiation. The results indicate either that the radiosensitization produced by the administration of hyperthermic temperatures before and after irradition result from two characteristically different molecular mechanisms, or that neither the rate of DNA strand break closure nor the number of DNA strand breaks remaining in nuclear DNA after irradiation accurately predict hyperthermic radiosensitization. These conclusions assume that no DNA strand breaks are below the resolution of this DNA damage assay and that a comparison between cytotoxicity and DNA repair after exposure to high radiation doses is valid.