柠檬酸钠促胃癌MGC-803细胞凋亡的作用及机制研究

Promoting effect of sodium citrate on apoptosis in gastric cancer cells and its mechanism

目的:探讨柠檬酸钠(SCT)促进胃癌MGC-803细胞凋亡的作用及机制。方法:胃癌MGC-803细胞分别经SCT(5、10、20 mmol/L)和5-FU(0.5 mmol/L)作用,以未处理的MGC-803为阴性对照,用流式细胞仪检测细胞周期分布及细胞凋亡率;比色法检测细胞内乳酸含量、磷酸果糖激酶1(PFK-1)活性及三磷酸腺苷(ATP)水平;Western blot检测细胞中Bcl-2、Bax、caspase-3及Cyt-c蛋白的相对表达量。结果:与阴性对照细胞比较,SCT处理的MGC-803细胞G2/M期阻滞与细胞凋亡明显增加;细胞内乳酸含量、PFK-1的活性和ATP水平均明显降低;细胞内Bcl-2的表达明显降低,而Bax、caspase-3和Cyt-c表达明显升高(均P<0.05)。5-FU对MGC-803细胞乳酸含量、PFK-1的活性无明显影响(均P>0.05),但其他作用与SCT相似。结论:SCT可促进MGC-803细胞凋亡,其作用可能与其抑制PFK-1的活性,降低糖酵解效率,并与线粒体凋亡通路的激活有关。

Objective： To investigate the ef ect of sodium citrate（SCT） on promoting apoptosis in gastric cancer cells and its mechanism. Methods： Gastric cancer MGC-803 cells were exposed to SCT（5, 10, 20 mmol/L） or 5-FU（0.5 mmol/L） respectively, using untreated MGC-803 cells as negative control. h en, the cell cycle distribution and apoptotic rate were analyzed by l ow cytometry, the intracellular lactate content, phosphofructokinase-1（PFK-1） activity and adenosine triphosphate（ATP） level were examined by colorimetric assay, and the expression of Bcl-2, Bax, caspase-3 and Cyt-c in MGC-803 cells were determined by Western blot analysis.Results： In SCT treated MGC-803 cells compared with negative control cells, the apoptosis and G2/M arrest were significantly increased, the intracellular lactate content, PFK-1 activity and ATP level were significantly reduced and Bcl-2 expression was signii cantly down-regulated, while the expressions of Bax, caspase-3 and Cyt-c were significantly up-regulated（all P〈0.05）. 5-FU exerted no significant effect on lactate content and PFK-1activity in MGC-803 cells（all P〉0.05）, but all other ef ects were similar to those of SCT.Conclusion： SCT can promote apoptosis in MGC-803 cells, and the mechanism may be associated with its reducing glycolysis via inhibiting PFK-1 activity and activating mitochondria-dependent apoptotic pathway.