大蒜素诱导人胃癌细胞M期阻滞的研究

Allicin induced cell cycle arrest in human gastric cancer cell lines

目的探讨大蒜素对人胃癌细胞系MGC803和SGC7901细胞周期的影响及其作用机制。方法以台盼蓝拒染法检测人胃癌细胞系MGC803和SGC7901细胞的增殖抑制率;以透射电镜观察两种胃癌细胞的直接损伤改变;以流式细胞仪及瑞士姬姆萨染色光镜观察两种胃癌细胞周期的改变;以SP免疫组化及RTPCR方法检测两种胃癌细胞的p21WAF1和p16INK4基因及蛋白表达的变化。结果大蒜素可抑制MGC803细胞生长,24h药物半数抑制浓度(IC50)为6.4μg/ml;也可抑制SGC7901细胞的生长,24hIC50为7.3μg/ml。12μg/ml的大蒜素作用两种胃癌细胞24h后,细胞出现急性直接损伤,膜系统改变明显。以3μg/ml、6μg/ml、9μg/ml终浓度大蒜素分别作用于两种胃癌细胞系24h后,与对照组比较,G0和G1期细胞周期百分比(%)明显减少,而G2和M期明显增加(P<0.01);6μg/ml大蒜素作用培养两种胃癌细胞24h后,与对照组比较,细胞分裂指数明显增加,提示两种细胞系经大蒜素处理后,细胞周期阻滞于M期。经大蒜素处理后,MGC803细胞的p21WAF1和p16INK4基因及蛋白表达均明显增加;SGC7901细胞的p21WAF1基因及蛋白表达明显增加。结论大蒜素可使MGC803及SGC7901两种细胞周期阻滞于M期;大蒜素的M期阻滞作用可能与其上调细胞的p21WAF1和p16INK4基因表达有关。

Objective To study the effect of allicin on cell cycle of human gastric cancer cell lines, MGC 803 and SGC 7901,and its possible mechanisms. Methods The gastric cancer cell lines MGC 803 and SGC 7901 were treated with allicin. Proliferation inhibitory rate was detected by trypan blue exclusion. Morphologic changes were observed by electron microscopy. The cell cycle was examined by flow cytometry and Giemsa staining. Expression of p21 WAF1 , p16 INK4 protein and mRNA was detected by immunohistochemistry and RT PCR. Results The gastric cancer cells were inhibited after exposure to allicin for 24 hr, The IC 50 was 6.4 μg/ml in MGC 803 cells and 7.3 μg/ml in SGC 7901cells. After exposure to allicin of 12 μg/ml for 24 hr, it caused the cytotoxic effect on the cells, including cellular membrane breakagy. After exposure to allicin of 3 μg/ml, 6 μg/ml and 9 μg/ml for 24 hr, compared with the control group, the proportion of cells in the G 0/G 1 phase was decreased and that in the G 2/M phase was increased significantly( P <0.01). After exposure to allicin of 6 μg/ml for 24 hr, compared with the control group, cell division index was much higher, suggesting that allicin could induce cell arrest in M phase. The expression levels of p21 WAF1 and p16 INK4 protein and mRNA in MGC 803 cells and p21 WAF1 protein and mRNA in SGC 7901 cells were markedly up regulated. Conclusion Allicin induce cell arrest of gastric cancer in M phase, which may be related to the up regulated expression of p21 WAF1 and p16 INK4 genes. [