土荆皮酸诱导宫颈癌细胞系HeLa凋亡的实验研究

Study on the Apoptosis Inducing Effect of Pseudolaric Acid B on Cervical Carcinoma Cell Line HeLa Cells

目的研究土荆皮酸(PAB)对体外培养的HeLa细胞的生物学效应和作用机制。方法用MTT法、流式细胞术、透射电镜检测体外培养的HeLa细胞在PAB作用下的增殖抑制及凋亡程度,用RT-PCR法检测p53/bcl-2/bax的表达水平。结果(1)PAB对HeLa细胞的增殖抑制作用随浓度升高而明显增强,其IC_(50)约10μmol/L。(2)流式细胞术证实10μmol/L PAB呈时间依赖性改变细胞周期分布,一方面降低G_0/G_1期的细胞比例,另一方面增高G_2/M期细胞的比例。(3)RT-PCR法显示HeLa细胞在10μmol/L PAB作用12、24、48 h均显示bax上调和bcl-2的下调,p53则未检测到表达。结论在体外PAB能抑制HeLa细胞增殖,诱导其凋亡,其诱导凋亡机制可能与bax的上调和bcl-2的下调相关。

Objective To investigate the biological effect and mechanism of action of pseudolaric acid B （PAB） on the cultured human HeLa cells in vitro. Methods MTT and flow cytometric assays were used to detect the cells proliferation inhibitory rate and apoptosis of HeLa cell in exposure to PAB; the morphological changes of apoptosis were observed with electron microscope; and the expressions of p53/bcl-2/bax mRNA were detected by RT-PCR. Results （1） HeLa cell proliferation was inhibited by PAB in a dose-dependent manner, the IC50 being about 10 μmol/L; （2） flow cytometry showed that the distribution of HeLa cell cycle was changed timedependently by 10 μmol/L PAB-treatment, showing decrease of G0/G1 phase cell percentage and increase of G2/M phase cell percentage; （3） the bax mRNA expression elevated and bcl-2 protein expression decreased markedly after being treated by 10 μmol/L PAB for 12 h, 24 h, and 48 h; while the expression of p53 mRNA could not be detected. Conclusion PAB can inhibit the proliferation and induce the apoptosis of Hela cells in vitro, and its molecular mechanism may be associated with up-regulating bax mRNA expression and down-regulating bcl-2 mRNA expression.