小檗碱对HeLa细胞凋亡及其凋亡相关蛋白表达的影响

Effect of berberine on apoptosis and expression of Bax and Bcl-2 proteins in HeLa cells

目的研究小檗碱对人宫颈癌HeLa细胞株增殖及凋亡的影响及其发生机制。方法采用MTT法观察小檗碱对HeLa细胞增殖的影响,DNA ladder、流式细胞仪等方法进行细胞凋亡检测,用Western blotting方法检测凋亡过程中相关蛋白Bcl-2和Bax表达的变化。结果小檗碱在体外试验中能明显抑制HeLa细胞的增殖,在一定的时间、剂量范围内呈时间-剂量依赖关系。20、40mg/L小檗碱作用48h后,细胞DNA片段分析可看到凋亡时降解形成的梯带,流式细胞仪检测到了细胞凋亡峰,各组的凋亡率分别是(16.7±2.8)%、(29.6±4.4)%,与对照组(1.9±0.6)%和5mg/L小檗碱组(2.3±0.8)%相比差异显著(P<0.01)。在凋亡过程中,Bax蛋白表达明显增高,而Bcl-2蛋白表达下凋。结论小檗碱体外能抑制HeLa细胞增殖并诱导其发生凋亡,其机制可能与Bax蛋白表达明显增高,而Bcl-2蛋白表达下调有关。

Objective To investigate the effect of herherine on growth and apoptosis of human cervical cancer cell line HeLa and its possible mechanism. Methods The effect of berberine on growth of HeLa cells was studied by MTT assay. Apoptosis of HeLa cells exposed to berberine was observed by flow cytometry and DNA gel electrophoresiso The expression of Bax and Bcl-2 was studied by Western blotting analysis. Results Berberine markedly inhibited the proliferation of HeLa cells in a time- and dose-depen- dent manner. After incubation of HeLa cells with 20 and 40 mg/L berberine for 48 h, DNA Ladder can be observed. A typical “sub-G1 peak” was checked by flow cytometry. There was a very low rate of natural apoptosis （1.9±0. 6）%, while in 5 mg/L berberine group, the apoptosis rate was （2.3±0. 8）%. After exposing HeLa cells for 48 h to 20 and 40 mg/L berberine, the apoptosis rate reached （16.7±2.8）% （P〈0.01） and （29.6±4.4）% （P〈0.01）, respectively.Western blotting showed the expression of Bax protein increased in HeLa cells, at the same time, the expression of Bcl-2 decreased in a dose-dependent manner. Conclusion In vitro berherine could inhibit the proliferation of HeLa cells and induce the apoptosis by promoting Bax and inhibiting Bcb2 expression in a dose-dependent manner.