霉酚酸对人结肠癌SW620细胞凋亡的诱导作用及其机制

Induction Effect of Mycophenolic Acid on Apoptosis of Human Colon Cancer Cell Line SW620 and Its Mechanism

研究霉酚酸(mycophenolic acid,MPA)对人结肠癌细胞株SW620凋亡诱导作用及其机制.MPA处理SW620细胞后,MTT法测细胞增殖抑制活性,Hoechst 33258染色法检验细胞核形态变化.提取DNA并电泳检验DNA断裂情况,流式细胞仪检测凋亡和细胞周期的影响,并检验MPA处理后细胞中Caspase-3活性.Caspase-3抑制剂z-DEVD-FMK及MPA共同作用SW620细胞,检验DNA断裂的逆转情况.结果表明:MPA有效抑制SW620细胞的增殖,IC50为0.11mol/L.在浓度高于1.0mol/L时,经过MPA处理后的细胞核呈现明显的固缩现象,基因组DNA断裂为DNA ladder.流式细胞仪的测定结果说明MPA使细胞生长周期停滞于G1/S期,并能够浓度、时间依赖诱导SW620细胞出现典型的Sub-G1凋亡峰.进一步的细胞Caspase-3活性分析结果证明MPA能剂量依赖地诱导细胞中Caspase-3的活性,Caspase-3抑制剂z-DEVD-FMK能够部分地逆转MPA诱导的凋亡,说明Caspase-3在凋亡过程中起到了非常重要的作用.因此,MPA能够部分通过激活细胞中Caspase-3途径有效诱导结肠癌细胞SW620的凋亡,这可能是MPA抑制细胞增殖的一个重要分子机制.

To study the induction effects of mycophenolic acid （MPA） on the apoptosis of human colon cancer cell line SW620 and its mechanism. After incubating SW620 cells with MPA, the viability of cells were determined with MTT assay, the cell nuclei were detected by Hoechst 33258 staining, and DNA fragmentation was detected by DNA electrophoresis. Flow cytometry was used to analyze the cell cycle and apoptosis. The activity of Caspase-3 was measured by a fluorimetric assay, z-DEVD-FMK, an inhibitor of Caspase-3, was used to confirm the pathway of apoptosis induced by MPA. MPA remarkably inhibited the proliferation of SW620 cells with an IC50 value of 0. 11 mol/L. After treatment with MPA, the cell nuclei exhibited characteristic condensation and DNA fragmentation.Flow cytometry results showed that the cell cycle was arrested at the G1/S phase,and the amount of cells at Sub- G1 increased with the concentration and treatment time of MPA. Further study showed that the activity of Caspase- 3 in the cells remarkably increased after MPA treatment,and Caspase-3 inhibitor could significantly inhibit the apoptosis induced by MPA. MPA could effectively induce the partly through a Caspase-3-dependent pathway. apoptosis of SW620 cells,and this effect was at least