阿司匹林对大肠癌LoVo细胞增殖、凋亡的影响及机制

Effect of Aspirin on Cell Proliferation and Apoptosis in Human Colorectal Cancer LoVo Cells and Its Mechanism

目的 观察阿司匹林对人结肠癌细胞系LoVo细胞增殖、凋亡的影响及探讨可能的作用机制.方法 用不同浓度阿司匹林处理体外培养的LoVo细胞24、48、72h,MTT法检测其对结肠癌LoVo细胞增殖的影响,倒置显微镜下观察细胞的形态学变化,阿司匹林（浓度分别为2、4、8mmol/L）分别处理LoVo细胞48h,行流式细胞仪检测细胞凋亡,分光光度计检测easepase-3相对活性,激光共聚焦显微镜检测细胞内Ca2＋浓度的变化,Western blot法检测bcl-2、bax基因表达情况.结果 阿司匹林（浓度1～10mmol/L）能显著抑制LoVo细胞增殖,呈剂量、时间依赖性;倒置显微镜下可观察到典型的细胞凋亡形态;阿司匹林处理LoVo细胞48h后,细胞凋亡率分别为11.4％、22.3％、37.1％,对照组凋亡率为2.4％;阿司匹林处理细胞48h后,casepase-3相对活性显著增加;阿司匹林能上调bax的表达并下调bcl-2表达,呈剂量依赖性.结论 阿司匹林均能抑制LoVo细胞的增殖并诱导其凋亡,其作用机制可能为增加细胞内Ca2含量、casepase-3活性及上调bax的表达并下调bcl-2表达.

Objective To investigate the effect of Aspirin cell proliferation and apoptosis in human colorectal cancer LoVo cells and discuss their possible mechanisms. Methods LoVo cells were cultured in vitro. After treatment by Aspirin at different concentrations re spectively at different time （24,48,72h） , the cell survival was determined by the MTT method. The changes of cell morphology were ob served by inverted microscope. Apoptosis was detected by flow cytometry. The relative activity of caspase -3 was monitored by spectro photometer. The concentration of intracellular calcium was investigated by laser confocal sanning microscope with calcium - flourecent probes - Fluo - 3/AM. The changes of protein expression of bcl - 2 and bax were detected by western blot. Results From the data of MTT, the cell proliferation of human colorectal cancer LoVo cells was inhibited by Aspirin in a dose - dependent and time - dependent manner. Typical apoptosis morphology of LoVo cells was observed by inverted microscope. Flow cytometry assays showed that Aspirin sig nificantly induced apoptosis in LoVo ceils. After treated with Aspirin, the apoptosis rate of Lovo cells was 11.4 % , 22.3% , and 37.1% respectively, which showed an obvious concentration - effect relationship. The relative activity of caspase - 3 of Aspirin group was 1.29 ± 0.06, 1.85 ± 0.08, 2.47 ± 0.08, respectively. The data of western blot showed that Aspirin up - regulated bax and down - regulated bcl -2 expression in a dose - dependent manner in LoVo cells. Conclusion Aspirin can inhibit the proliferation of LoVo cells and induce apoptosis, and the mechanism of Aspirin on apoptosis may be related to the increase of concentration of intracellular calcium, up regulation of bax expression and down regulation of bcl - 2 expression.