硫利达嗪诱导SW480细胞凋亡的机制

Mechanism of thioridazine-induced apoptosis of human colorectal cancer SW480 cells

目的：研究硫利达嗪对结肠癌SW480细胞增殖及凋亡的影响。方法应用5-30μmol/L硫利达嗪处理SW480细胞，MTT法检测细胞增殖抑制率；Hoechst33342细胞核染色法观察细胞凋亡的形态学改变；流式细胞仪检测细胞凋亡率、细胞周期；RT-qPCR分析PDCD4、c-MYC、BCL2、CCND1、CASPASE3、PARP1、CDK4、EIF4A基因表达水平；Western blotting检测AKT、p-AKT、PDCD4蛋白表达水平。结果 MTT结果表明硫利达嗪抑制SW480细胞的增殖，硫利达嗪处理细胞后出现核固缩、染色质凝集和核碎片化等典型的细胞凋亡特征；流式检测表明硫利达嗪诱导G0/G1期阻滞，细胞凋亡增加。RT-PCR结果表明硫利达嗪处理细胞后PDCD4表达上调，CCND1、CDK4、c-MYC、BCL2、CASPASE3、PARP1和EIF4A表达下调。免疫印迹分析结果显示PDCD4蛋白表达上调，p-AKT蛋白表达下调。结论硫利达嗪能够抑制人结肠癌SW480细胞的增殖，并诱导其凋亡，其机制可能与抑制PI3K/AKT信号通路导致PDCD4表达水平升高有关。

Objective To study the effect of thioridazine on the proliferation and apoptosis of human colorectal cancer SW480 cells. Methods SW480 cells were treated with different concentrations of thioridazine, and MTT assay was used to evaluate the cell inhibition rate. Hoechst 33342 staining was performed to demonstrate the cell morphology changes. Flow cytometry was used to determine the cell apoptosis and cell cycle changes. RT-qPCR was used to detect PDCD4, c-MYC, BCL2, CCND1, CASPASE3, PARP1, CDK4 and EIF4A mRNA expressions, and Western blotting was employed to assay AKT, p-AKT, and PDCD4 protein expression levels. Results MTT results showed that thioridazine inhibits the proliferation of SW480 cells. SW480 cells treated with thioridazine presented with such typical features of apoptosis of karyopyknosis, chromatin condensation and nuclear fragmentation. Flow cytometry showed that thioridazine was a cell cycle-specific drug and caused cell cycle arrest at G1/G0 phase and an increased cell apoptosis rate. Thioridazine treatment of the cells resulted in up-regulated PDCD4 mRNA expression and down-regulated mRNA expressions of CCND1, CDK4, c-MYC, BCL2, CASPASE3, PARP1 and EIF4A, increased PDCD4 protein expression and reduced p-AKT protein expression. Conclusion Thioridazine inhibits the proliferation and induces apoptosis of SW480 cells by up-regulating PDCD4 and inhibiting PI3K/Akt pathway.