^(16)O^(6+)辐照诱导的人肝癌细胞DNA双链断裂及其修复

INDUCTION AND REPAIR OF DNA DOUBLE-STRAND BREAKS IN HUMAN HEPATOMA CELLS IRRADIATED WITH ^(16)O^(6+)

用倒转脉冲场凝胶电泳（ＰＩＧＥ） 研究了 ３．１７ＭｅＶ／ｕ１６Ｏ６＋ 诱导的肝癌细胞 ＤＮＡ双链断裂（ＤＳＢ）及其修复效应。结果表明： ＤＳＢ的诱导与辐照剂量呈正相关，其产额为 ０．４３ＤＳＢｓ／１００Ｍｂｐ：Ｇｙ，与 ６０Ｃｏγ射线相比相对生物学效应为 １．６９。 ＤＳＢ片段重接一半所需要的时间（ｔ１／２）与剂量有关，剂量越大，ｔ１／２越长。重接的方式主要表现为小片段连接为较大的片段。

Pulsed-field gel electrophoresis has been applied to analyse the induction and repair of DNA double-strand breaks (DSB) in human hepatoma SMMC-7721 cells exposed to 3.17MeV/u 16O6+. It shows that the DSB yields are 0.43DSBs/100Mbp/Gy and compared with 60Co γ-rays , the relative biological effectiveness (RBE) of 16O6+ is 1.69. The half time of DSB fragments being repaired (t1/2) is relevant to the dose; the higher the dose is, the longer the time is. The main way for DSB repair is the rejoining of smaller fragments into larger ones.