【摘要】 比较研究X射线对人子宫颈癌细胞(He La)、人肝癌细胞(Hep G2)和人粘液表皮样癌细胞(MEC-1)的辐射敏感性。X射线照射三株细胞至吸收剂量2、4、6、8 Gy后0.5、4和24 h,用克隆形成实验测定细胞增殖,中性彗星电泳法检测DNA双链损伤(DNA double strand breaks,DSB),免疫荧光染色法检测磷酸化组蛋白H2AX(γH2AX)焦点的形成。结果显示:2、4、6、8 Gy剂量组及照射后不同时间点均以Hela细胞的存活分数(Survival fraction,SF)最高;CASP软件分析显示,DSB增加呈现时间和剂量依赖关系,照射后4 h尾矩(Tail moment,TM)增加最为明显,其中以MEC-1细胞增加最为显著;照射后0.5和4 h,γH2AX阳性细胞率达到100%,照射后24 h逐渐下降,其中Hela细胞下降最为明显。结果提示,克隆形成实验、中性彗星电泳和γH2AX焦点检测法的联合使用能有效预测肿瘤细胞辐射敏感性。更多还原

【Abstract】 The present study was to compare the X-ray sensitivity in human cervical cancer cell line He La, human hepatoma cell line Hep G2, and human mucoepidermoid carcinoma cell line MEC-1. At 0.5, 4, and 24 h after X-ray irradiation with absorbed doses of 2, 4, 6, and 8 Gy, clonogenic assay, neutral comet electrophoresis, and immunofluorescence staining were used to evaluate the cell proliferation, DNA double-strand breaks(DSBs), and formation of phosphorylated histone H2 AX(γH2 AX) foci. The results showed that He La cells had the highest survival fraction(SF) for 2, 4, 6, and 8 Gy group at different time points after irradiation. Comet assay software project(CASP) analysis showed that DSBs increased with irradiation time, and absorbed dose. Tail moment(TM) increased most significantly at 4 h after irradiation, especially in the MEC-1 cells. The γH2 AX phosphorylation level in the three cell lines reached 100% at 0.5 and 4 h after irradiation, and then gradually decreased by 24 h, this decline in γH2 AX phosphorylation was the most obvious in He La cells. The above mentioned results showed that the combined use of clonogenic assay, neutral comet electrophoresis, and phosphorylated γH2 AX foci detection can effectively predict the radiosensitivity of tumor cells.更多还原