线粒体DNA 4977 bp缺失和彗星分析评价肿瘤细胞的辐射敏感性

摘要

Objective To explore the feasibility of determining radiosensitivity of human tumor cell lines in vitro using the assay of mtDNA 4977 bp deletion and comet assay.Methods Three human tumor cell lines were selected in this study,HepG2,EC-9706 and MCF-7.The surviving fraction(SF),the ratio of mtDNA 4977bp deletion and DNA damage were detected by MTT assay,nested PCR technique and comet assay,respectively.Results The results of MTT assay showed that the radiosensitivity of HepG2 and EC-9706 was higher than that 0f MCF-7.The ratio of mtDNA 4977 bp deletion of HepG2 and EC-9706 was higher significantly than that of MCF-7(P＜0.05)after 8 Gy irradiation,which implied that the radiosensitivity of HepG2 and EC-9706 was higher than that of MCF-7.The difierence of radiosensitivity among these three tumor cell lines was significant after 8 Gy γ-ray irradiation.Conclusions Combination of many biological parameter is helpful to evaluate the radiosensitivity of tumor cells more accurately.%目的 探讨mtDNA4977bp缺失和彗星分析用于肿瘤细胞辐射敏感性检测的可行性.方法 选取3种不同肿瘤细胞株:肝癌细胞(HepG2)、食管癌细胞(EC-9706)和乳腺癌细胞(MCF-7).采用MTT法检测肿瘤细胞经γ射线照射后的存活分数(SF);巢式PCR法测肿瘤细胞的mtDNA 4977bp缺失率;单细胞凝胶电泳(SCGE)检测肿瘤细胞的DNA断裂水平.结果 用MTT法发现HepG2和EC-9706细胞的辐射敏感性高于MCF-7细胞.8 Gy照射后HepG2和EC-9706 mtDNA 4977 bp缺失率明显高于MCF-7细胞(P＜0.05),证实HepG2和EC-9706细胞的辐射敏感性高于MCF-7细胞.多种方法分析结果说明3种肿瘤细胞在8 Gy照后表现出的辐射敏感性差异有统计学意义.结论 多种生物学指标的综合应用,可能更加客观准确地评价肿瘤细胞的辐射敏感性.