高本底辐射居民DNA损伤修复能力研究

Study on the repair level of DNA damage in inhabitants of natural high background radiation area

目的探讨小剂量慢性长期连续照射人群的DNA损伤修复能力。方法选择我国阳江天然放射性高本底辐射地区（HBRA）的53名50~59岁男性居民作为研究对象,另选择恩平市横坡镇（CA）出生并长大的年龄相仿的男性居民作为对照人群。分别抽取他们周围血5 ml,利用逆转录-聚合酶链反应（RT-PCR）测定周围血中有核细胞的Ku70基因、切除修复鼠缺陷交叉互补蛋白1（ERCC1）、错配修复hMSH2基因、O6-甲基鸟嘌呤甲基转移酶（MGMT）基因表达水平。结果在HBRA和CA组人群的周围血有核细胞中,Ku70基因表达水平分别为（0.438±0.351）、（0.389±0.271）,ERCC1基因表达水平分别为（0.228±0.112）、（0.193±0.115）,hMSH2基因表达水平分别为（0.365±0.222）、（0.279±0.214）,MGMT基因表达水平分别为（0.585±0.319）、（0.414±0.365）。与对照组相比,高本底辐射居民Ku70、ERCC1、hMSH2水平略升高,但差异无统计学意义（P〉0.05）,MGMT基因表达增强,差异有统计学意义（P〈0.05）。结论MG-MT基因可能参与了天然放射性高本底辐射所致DNA损伤修复。

Objective To examine the repair level of DNA damage in inhabitants living in Yangjiang natural high background radiation area（HBRA）.Methods 53 inhabitants aged from 50 to 59 years old in HBRA were selected as the exposure group and those in Enping control area（CA） as the control group.Expression levels of gene Ku70,ERCC1（cross complementing rodent repair deficiency gene）,hMSH2 and MGMT（of O6 methylguanine-DNA methyltransferas） were determined in blood with RT-PCR（reverse transcription PCR）.Results In HBRA and CA,expressions of gene Ku70,ERCC1,hMSH2 and MGMT were（0.438±0.351）and（0.389±0.271）,（0.228±0.112） and（0.193±0.115）,（0.365±0.222） and（0.279±0.214）,（0.585±0.319） and（0.414±0.365）,respectively.Compared to CA,expression level of MGMT increased significantly in HBRA（P0.05）,expressions of Ku70,ERCC1 and hMSH2 increased,but there were no statistical significance（P0.05）.Conclusion MGMT gene can take part in DNA damage repair induced by natural high background radiation.