丝裂霉素对体外胃癌细胞DNA损伤和增殖的影响

目的探讨丝裂霉素对体外胃癌细胞DNA损伤和增殖的影响。方法选用不同浓度丝裂霉素处理体外培养的胃癌细胞SGC-7901，利用免疫荧光和Western blot技术，分别检测γH2AX的焦点形成和蛋白水平变化；使用MTT法检测SGC-7901细胞的增殖情况。结果丝裂霉素的作用浓度和作用时间存在交互效应，除400 μg/ml外，平均γH2AX焦点数和焦点细胞率呈逐渐增加趋势（P<0.05）；400 μg/ml时，6 h组平均γH2AX焦点数和焦点细胞率低于4 h组，差异有统计学意义（P<0.05）。随丝裂霉素作用时间延长，γH2AX蛋白水平呈先升后降趋势，差异有统计学意义（P<0.05）。MTT结果显示，丝裂霉素对SGC-7901细胞的增殖有明显抑制作用（P<0.05）。结论γH2AX可敏感反应丝裂霉素对胃癌细胞DNA的损伤，丝裂霉素对体外胃癌细胞增殖抑制明显。

Effect of Mitomycin on DNA Damage and Proliferation of Gastric Cancer Cell in vitro

ObjectiveTo study mitomycin-induced DNA damage and proliferation inhibition of gastric cancer cells by detection of γH2AXin vitro.MethodsMitomycin with different concentrations was used to incubate gastric cancer cell line SGC-7901cells in vitro.Focus formation and protein levels of γ H2AX were detected by immunofluorescence and western-blotting techniques, respectively, MTT assay was used to detect the proliferation of gastric cancercell.ResultsThe mitomycin existed concentration and time interaction effect. Except 400 μg/ml, the averagenumber of γH2AX foci and focus cell rate were gradually increased (P<0.05). At 400 μg/ml, in 6 h group averagenumber of γH2AX foci and focus of cell rate were less than those in 4 h group (P<0.05). With time of mitomycintreatment prolonged,γH2AX protein levels were increased and then decreased (P<0.05). MMC significantly inhibitedthe proliferation of SGC-7901 (P<0.05).ConclusionγH2AX was a sensitive marker to predict DNA damage andproliferation inhibition of gastric cancer cell induced by Mitomycin C in vitro.