黄芩苷诱导人乳腺癌细胞株MDA-MB-231凋亡作用的研究

Study on Baicalin Induced Apoptosis of Human Breast Cancer Cell Line MDA-MB-231

目的:探讨植物雌激素结构类似物黄芩苷诱导人乳腺癌雌激素受体阴性细胞株MDA-MB-231(ER-)凋亡的作用。方法:MTT法测定不同剂量黄芩苷对MDA-MB-231细胞株增殖的抑制作用;透射电镜检测细胞凋亡及黄芩苷的作用;流式细胞术分析黄芩苷对MDA-MB-231细胞周期变化的影响;RT-PCR技术分析黄芩苷对MDA-MB-231细胞bcl-2、baxmRNA水平表达的影响。结果:在一定剂量范围内,黄芩苷对MDA-MB-231细胞增殖的抑制作用呈时效、量效关系,IC50为151μmol/L;透射电镜结果显示黄芩苷作用细胞48 h后出现明显的凋亡现象,流式细胞仪检测结果显示细胞凋亡率随着黄芩苷的浓度增加而增大,并阻滞细胞于G2/M期;RT-PCR结果表明,黄芩苷作用细胞后baxmRNA水平的表达增加而bcl-2的表达降低。结论:黄芩苷可以抑制MDA-MB-231细胞的增殖,诱导细胞凋亡的发生,可能是通过调节bcl-2、bax的表达和干涉细胞周期而发挥诱导人乳腺癌MDA-MB-231细胞凋亡的作用。

Objective; To study the baicalin induced apoptosis of human breast cancer cell line MDA- MB-231（ER- ）. Methods： The inhibitory effect of different concentration of baicalin on the MDA-MB-231 cells was measured by MTT method. Transmission electron microscope was employed to observe the apoptosis of the cells. Cell cycle was analysed by flow cytometry. The mRNA level expression of bcl-2 and bax was determined by RT-PCR. Results： The proliferation of MDA-MB-231 cells was inhibited by baicalin in dose- and time-dependent manner and the IC50 was 151 μmol/L. The apoptotic rate of the baicalin-treated MDA-MB-231 cells increased significantly at 48 h. Flow cytometer analysis also revealed that most of the baicalin-treated MDA-MB-231 cells were arrested in the G2/M phase. Typically apoptotic characteristics such as condensed chromatin and apoptotic bodies were observed after being treated with baicalin for 48 h. The results of RT-PCR showed that the expression of bax was up-regulated; meanwhile, the expression of bcl-2 was down-regulated. Conclusion： Baicalin could inhibit the proliferation of MDA-MB-231 cells through apoptosis by regulating the expression of bcl-2, bax and intervening the process of the cell cycle.