应用γH2AX评估丝裂霉素致胃癌细胞DNA损伤

Application of γH2AX to assess DNA damage of gastric cancer cell induced by Mitomycin

目的通过检测γH2AX,评估丝裂霉素对体外胃癌细胞DNA的损伤;同时,观察丝裂霉素对体外胃癌细胞增殖的影响。方法体外培养胃癌细胞株SGC-7901细胞,选用丝裂霉素处理,利用免疫荧光和Western-Blotting技术,分别检测γH2AX的焦点形成和蛋白水平变化;采用MTT法检测SGC-7901细胞的增殖情况。结果与对照组相比,实验组在每个时间点的γH2AX细胞百分数和平均焦点数都呈增加趋势,200μg/mL组和400μg/mL组的增加尤为明显,与对照组的差异有显著性(P<0.01)。用400μg/mL的丝裂霉素孵育SGC-7901细胞,γH2AX蛋白的水平变化呈先升后降趋势,差异有显著性(P<0.05)。MTT结果显示,丝裂霉素对SGC-7901细胞的增殖抑制明显(P<0.05)。结论γH2AX可敏感反应丝裂霉素对胃癌细胞DNA的损伤,潜在的临床应用价值极高;丝裂霉素对体外胃癌细胞增殖抑制明显。

To evaluate Mitomycin-induced DNA damage of gastric cancer cells byγH2AX measure- ment, along with effect of Mitornycin on proliferation of gastric cancer cell in vitro investigated. [ Methods ] H2AX focus formation and protein levels were accessed through immunofluorescence and western-blotting techniques on gastric cancer cell line SGC-7901 with and without the presence of Mitomycin administration in vitro. MTTassay was used for detection of gastric cancer cell proliferation of. [Results] Compared with the control group, the per- centage of γH2AX positive ceils and the mean value of γH2AX focus per cell showed gradually increase at each time point, statistically significant increase at 200 μg/mL Mitomycin a 400 μg/mL Mitomycin incubation （P 〈0.01）. 400 μg/mL Mitomycin treatment induced an increased γH2AX expression followed with reduced γ H2AX protein lev- el（P 〈0.05）. MTT assay displayed the inhibitory effect of Mitomycin on gastric cancer cell proliferation （P 〈0.05）. [Conclusions] Mitomycin causes inhibitory effect on gastric cancer cell proliferation. γH2AX shows a sensitive re- sponse to Mitomycin-induced DNA damage on gastric cancer cells, serving as a potentially novel and promising therapeutic intervene in cancer treatment.