磷酸化组蛋白预测肝癌细胞对某些化疗药物的敏感性

Phosphorylated H2AX in predicting sensitivity of hepatic cancer cell line HepG2.215 to chemotherapeutic drugs

目的:探讨以磷酸化组蛋白(phosphorylated H2AX,γH2AX)为检测指标预测肝癌细胞HepG2.215对依托泊苷、多柔比星、丝裂霉素和顺铂等化疗药物敏感性的可行性和可靠性。方法:分别以质量浓度指数梯度为1、2、4、20的依托泊苷、多柔比星、丝裂霉素和顺铂等4种化疗药物作用于肝癌细胞HepG2.215,以无药物作用的肝癌细胞为对照组,采用流式细胞术(FCM)检测肝癌细胞中γH2AX阳性表达细胞的百分数,采用免疫细胞化学法检测肝癌细胞内形成的γH2AX灶点数,采用MTT比色法检测化疗药物作用对肝癌细胞增殖的抑制率。分析4种药物作用下肝癌细胞中γH2AX灶点数与γH2AX阳性细胞百分数的相关性;分析各药物不同的质量浓度与肝癌细胞中γH2AX阳性细胞百分数、γH2AX灶点数,以及肝癌细胞增殖抑制率的相关性;分析在各药物作用下,肝癌细胞中γH2AX阳性百分数和γH2AX灶点数分别与细胞增殖抑制率的相关性。结果:4种药物作用下肝癌细胞中γH2AX灶点数与γH2AX阳性细胞百分数呈正相关(均P<0.05);各药物不同质量浓度分别与肝癌细胞中γH2AX阳性细胞百分数、γH2AX灶点数,以及肝癌细胞增殖抑制率呈正相关(均P<0.01);在各药物作用下,肝癌细胞中γH2AX阳性百分数和γH2AX灶点数分别与细胞增殖抑制率呈正相关(均P<0.05)。结论:在上述4种化疗药物对肝癌细胞HepG2.215的作用中,γH2AX在细胞水平预测肝癌细胞对药物的敏感性有较高的可行性和可靠性。

Objective： To study the feasibility and reliability of using phosphorylated H2AX （γH2AX） as a predictor for sensitivity of hepatic carcinoma cell HepG2.215 to chemotherapy agents： etoposide, doxorubicin, mitomycin, and cisplatin. Methods： HepG2.215 cells were exposed to etoposide, doxorubicin, mitomycin or cisplatin of 1, 2, 4 and 20 concentration index （CI）. Untreated HepG2.215 cells were taken as control. The proportion of HepG2.215 cells expressing γH2AX was measured by flow cytometry, the number of γH2AX foci in HepG2.215 cells was measured by immunocytochemistry, and cell proliferation was measured by MTT. The correlation between the number of γH2AX foci and the percentage of HepG2.215 cells expressing γH2AX in HepG2.215 cells was analyzed; the correlation of CI with the percentage of HepG2.215 cells expressing γH2AX or γH2AX foci and inhibitory rate of cell proliferation was analyzed; and the correlation of inhibitory rate of cell praliferation with the percentage of HepG2.215 cells expressing γH2AX or γH2AX foci was also analyzed. Results： There was a positive correlation between the number of γH2AX foci and the percentage of HepG2.215 cells expressing γH2AX in HepG2.215 cells after treatment with the above 4 agents （all P 〈0. 05）. A positive correlation was also found between CI of the above agents and the percentage of HepG2.215 cells expressing γH2AX or γH2AX foci and inhibitory rate of cell praliferation （all P 〈0.01 ）. A positive correlation was also found between the percentage of HepG2.215 cells expressing γH2AX or γH2AX foci and inhibitory rate of cell pralif-eration （ all P 〈0.05 ）. Conclusion： It is feasible and reliable to use γH2AX for predicting the sensitivity of HepG2.215 cells to chemotherapy agents in this study.