转染Stat3β cDNA对人乳腺癌细胞的作用

目的 研究转染Stat3β cDNA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Stat3β cDNA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(Western blot)检测STAT3通路蛋白表达,流式细胞术(flow cytometry)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Stat3β cDNA的质粒pIRES-Stat3β;转染Stat3β cDNA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Stat3β cDNA的质粒pIRES-Star3β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。

The effect of transfecting Stat3beta cDNA on human breast cancer

OBJECTIVE: To study the effect of transfecting Stat3beta cDNA on human breast cancer. METHODS: Human breast cancer cells of the line SK-BR-3 were cultured and divided into 3 groups: Stat3beta transfection group (to be transfected with plasmid pIRES-Stat3beta containing Stat3beta by transient transfection technique), lipofectin 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. Western blotting was used to detect the expression of STAT3 protein. MTT method was used to examine the proliferation of the cells. RESULTS: Forty-eight hours after exposure to the plasmid pIRES-Stat3beta the transfection rate of the SK-BR-3 cells was 13.79%. SK-BR-3 cells expressed STA3 protein during proliferation. In comparison with the SK-BR-3 cells of other 3 group, the proliferation of the cells transfected with pIRES-Stat3beta was significantly decreased. Forty-eight hours after transfection, 81.09% of the cells transfected with the plasmid pIRES-Stat3beta accumulated at the G(0)/G(1) stage, a rate significantly higher than those of the other groups, and displayed a significantly higher rate of apoptosis. CONCLUSION: Transfection of plasmid pIRES-Stat3beta containing Stat3beta blocks the Stat3 pathway, thus inhibiting the proliferation and augment the apoptosis of human breast cancer cells and providing a novel gene therapy target.