转染Stat3βcDNA对人乳腺癌细胞的作用

The effect of transfecting Stat3β cDNA on human breast cancer

目的 研究转染Stat3βcDNA阻断人乳腺癌细胞系SK -BR -3细胞的Stat3信号传导通路对人乳腺癌细胞增殖和凋亡的影响。方法 应用阳离子脂质体介导的瞬时转染技术将携带Stat3βcDNA的质粒转入人乳腺癌细胞系SK- BR -3细胞中,流式细胞分选术将转染阳性细胞分离后,用四唑盐(MTT)比色试验检测细胞增殖能力,蛋白质印迹法(Westernblot)检测STAT3通路蛋白表达,流式细胞术(flowcytometry)检测细胞周期和凋亡。结果 转染48h后13. 79%SK -BR -3细胞被导入携带Stat3βcDNA的质粒pIRES Stat3β;转染Stat3βcDNA后p STAT3表达水平下降,细胞增殖能力受到抑制,出现G0 /G1 期的阻滞、S期比例下降,以及细胞凋亡增加。结论 转染携带Stat3βcDNA的质粒pIRES- Stat3β可以阻断SK- BR- 3细胞中Stat3通路,抑制人乳腺癌细胞的增殖,促进其凋亡,可能为乳腺癌的基因治疗提供新的靶点。

Objective To study the effect of transfecting Stat3β cDNA on human breast canc er. Methods Human breast cancer cells of the line SK-BR-3 were cultured and div ided into 3 groups: Stat3β transfection group (to be transfected with plasmid pIRES-Stat3β containing Stat3β by transient transfection technique), lipofect in reagent transfection group pIRES-EGFP transfection group, and control group. The positively transfected cells were isolated by fluorescence-activated cell sorter. Flow cytometry was used to analyze the cell cycles and cell apotosis. We stern blotting was used to detect the expression of STAT3 protein. MTT method wa s used to examine the proliferation of the cells. Results Forty-eight hours after exposure to the plasmid pIRES-Stat3β the t ransfection rate of the SK-BR-3 cells was 13.79%. SK-BR-3 cells expressed ST A3 protein during proliferation. In comparison with the SK-BR-3 cells of other 3 group, the proliferation of the cells transfected with pIRES-Stat3β was sig nificantly decreased. Forty-eight hours after transfection, 81.09% of the cells transfected with the plasmid pIRES-Stat3β accumulated at the G 0/G 1 stage, a rate significantly higher than those of the other groups, and displayed a sig nificantly higher rate of apoptosis. Conclusion Transfection of plasmid pIRES-Stat3β containing Stat3β blocks the Stat3 pathway, thus inhibiting the proliferation and augment the apoptosis of hu man breast cancer cells and providing a novel gene therapy target.