肝癌SMMC-7721细胞受X线照射后线粒体DNA部分编码区断裂损伤状况  

Damages within coding region of mitochondrial DNA in human liver cancer cell line SMMC-7721 exposured to X-ray

作　　者：王璐[1] 时多[1] 蒋恒义[1] 王学敏[1] 缪明永[1] 高春芳[2] 

机构地区：[1]第二军医大学基础部生物化学与分子生物学教研室,上海200433 [2]第二军医大学东方肝胆医院实验诊断科,上海200438

出　　处：《第二军医大学学报》2008年第4期361-364,共4页Academic Journal of Second Military Medical University

基　　金：国家自然科学基金(30472175，30171030)~~

摘　　要：目的:研究肝癌SMMC-7721细胞受不同剂量的X线照射后线粒体DNA编码区的断裂损伤状况。方法:对SMMC-7721细胞照射不同剂量(0、20、30、50 Gy)的X线,根据人线粒体DNA编码区的序列设计引物,用接头介导的PCR (LM—PCR)以及基因扫描技术来检测其断裂位点及程度。结果:通过基因扫描的方法,发现经不同剂量X线照射后SMMC- 7721细胞线粒体DNA编码区存在对X线敏感的位点,断裂损伤的程度和辐照剂量呈正相关,并且这些位点的分布是非随机的;在SMMC-7721细胞线粒体DNA编码区中,重链的损伤程度较轻链高。结论:SMMC-7721细胞受不同剂量的X线照射后线粒体DNA编码区有明显的断裂损伤,线粒体DNA的变化对肿瘤的临床治疗有一定的指导价值。Objective：To study the damages within the coding region of the mitochondrial DNA in a human liver cancer cell line SMMC-7721 after exposure to different doses of X-ray irradiation. Methods： SMMC-7721 cells were radiated by different doses of X-ray （0,20,30,and 50 Gy）. Primers for multiple PCR detection were designed according to the sequences of the coding region of human mitochondrial DNA, and the degree and location of mitochondrial DNA breaks were examined by LM-PCR （ligation mediated-PCR） and gene scanning technique. Results： The results of gene scanning showed the existence of X-ray sensitive breakpoints in the mitochondrial DNA coding region in human liver cancer cell line SMMC-7721, the degree of damage increased with the irradiation doses; the sensitive breakpoints were not distributed at random. The damage of heavy strand was severe than that in the light strand. Conclusion： X-ray irradiation can cause obvious damage to the coding region of the mitochondrial DNA in human liver cancer cell line SMMC-7721,and the changes of mitochondrial DNA may play a role in the clinical therapy of cancer.

关 键 词：线粒体DNA X线 辐射 肝肿瘤 

分 类 号：R735.7[医药卫生—肿瘤]