高LET重离子照射人肿瘤细胞的DNA双链断裂及修复研究  

DNA double strand break and repair of human tumor cells irradiated by high LET heavy ions

作　　者：郭传玲[1] 王菊芳[1] 魏巍[1] 荆西刚[1] 金晓东[1] 李文建[1] 

机构地区：[1]中国科学院近代物理研究所

出　　处：《核技术》2007年第9期750-753,共4页Nuclear Techniques

基　　金：科技部重大基础前期研究专项基金(2003ccb00200);国家自然科学基金重点项目(100335050)

摘　　要：依托兰州近代物理研究所的HIRFL装置对人肝癌细胞SMMC-7721进行高LET的重离子辐照,同时利用脉冲场凝胶电泳研究高LET辐射引起的细胞DSB及其修复的特点。对于不同离子的辐射进行了比较分析,探索重离子的辐射生物学效应机理。结果发现,随着剂量的增加,初始DSB在给定剂量范围内呈线性增长,LET较高的氩离子的剂量效应曲线具有较大的斜率。对于DSB分布情况的研究发现,LET不同,大小片段的分布随着剂量的变化呈现不同的变化情况。修复研究显示两种LET辐射的快修复在30min左右都已经结束,此后都开始了慢修复,对于高LET的氩离子辐射来说,快修复和慢修复完成的修复量均高于较低LET的碳离子辐射。4h时,两种辐射残余的DSB基本一致。结果证明了高LET辐射下初始DSB与剂量的线性依赖关系,且发现不同种类的离子辐射引起的DSB的剂量效应曲线的斜率不同。结果也显示了DSB的非随机分布现象和DSB修复的双阶段模式,发现LET、离子种类和剂量对于DSB的片段非随机分布同时存在影响,同时修复结果提示慢修复机制和错修复在高LET辐射引起损伤的修复研究中可能具有重要意义。The study aims at exploring mechanisms of the biological effect induced in human hepatoma SMMC-7721 cells irradiated by high LET heavy ions. Carbon （^12C^6＋） and argon （^40Ar^＋） ions from Heavy Ion Research Facility at Lanzhou （HIRFL） and pulse-field gel electrophoresis were used in this study. The results showed that in the given dose range the DSB induction increased linearly with dose and the slope of dose-effect curve of the ^40Ar^＋ ions with higher LET was bigger. Meanwhile we found that when dose increased there were different varieties of the distribution of DSB fragments induced by ions with different LET and the quick repair to DSB was completed in 30 minutes and then came the slow repair phase for two kinds of irradiation. For the ^40Ar^＋ ions irradiation with higher LET the amount of repaired DSB was larger than ^12C^6＋ ions irradiation in both repair phases and there was little distinction between the residual DSB induced by two kinds of irradiation. The results approve the linear relationship between DSB induction and dose and display the influence of ion kind to the slope of dose-effect curve. As well as the results affirm the non-random distribution of DSB induced by heavy ions and the two phase mode of DSB repair and show the synchronously introduced impact to the distribution of DSB by LET, ion kind and dose. Slow repair and misrepair should be given attention when research on repair to DSB induced by heavy ions is involved.

关 键 词：重离子 DNA双链断裂 线性能量转移 DSB修复 

分 类 号：R730[医药卫生—肿瘤] Q691[医药卫生—临床医学]