Development of DNA repair assay for ionizing radiation damages.

电离辐射诱导形成不同类型的DNA损伤。电离辐射产生的氧自由基产生单链和双链断裂以及各种环饱和、环碎片化和氧化碱衍生物。这种损伤的修复机制尚未得到很好的研究。我尝试开发无细胞修复系统来研究体外修复。将质粒DNA辐照后与细胞提取物混合，重新连接断裂的DNA链，恢复转录和修复DNA合成。用该系统检测了伽玛射线辐照后DNA的修复。我现在试着开发这个定量分析系统。我还发现氧胁迫诱导了一些紫外线诱导损伤的修复系统，我们现在正在研究氧胁迫对电离辐射诱导损伤DNA修复的影响。

Ionizing radiation induce the formation of different and diverse types of DNA lesions. Oxygen free radicals produced by ionizing radiation generate single and doublestrand breaks as well as a variety of ring-saturated, ring-fragmented, and oxidized base derivatives. The repair mechanisms of such lesions are not well investigated. I tried to develop the cell free repair system to study the repair in vitro. Plasmids DNA are irradiated and mixed with cell extract and rejoining of DNA strand breaks, recovery of transcription and repair DNA synthesis. The repair of DNA irradiated with gamma ray was detected with this systems. And I am now try to develop this system for quantitative analysis. I also find the oxygen stress induce the some repair systems for UV induced lesions and we are now examining the effect of oxygen stress on DNA repair for ionizing radiation induced damages.