冬凌草甲素通过PI3K/Akt通路诱导MDA-MB-231细胞的凋亡

Oridonin induces MDA-MB-231 cells apoptosis through PI3K/Akt pathway in vitro

目的:研究冬凌草甲素对人乳腺癌MDA-MB-231细胞增殖产生的影响,初步探讨其作用机理。方法:体外培养人乳腺癌MDA-MB-231细胞,采用6、12、24μmol/L冬凌草甲素对其进行处理,采用倒置显微镜进行细胞形态学观察,MTT比色法检测细胞存活率,流式细胞术检测细胞凋亡率,Western blotting检测凋亡相关蛋白procaspase-3、PARP及Akt、p-Akt、p-GSK3β表达的变化。结果:冬凌草甲素作用MDA-MB-231细胞24h后,可观察到细胞凋亡的形态学改变,以24μmol/L组最为明显。实验组与对照组相比,细胞存活率显著降低、凋亡率显著升高(P<0.01),具有时间和剂量依赖性,凋亡相关蛋白procaspase-3下调,caspase-3底物PARP被逐步剪切,并伴随p-Akt、p-GSK3β蛋白水平下调(P<0.05)。结论:冬凌草甲素可有效抑制人乳腺癌MDA-MB-231细胞的增殖,诱导其凋亡,机制与PI3K/Akt通路的抑制有关。

AIM. To research the proliferation inhibitory effect of oridonin on human breast cancer MDA-MB-231cells and explore the mech- anism of the inhibitory effect. METHODS： MDA-MB-231 cells were incubated with 0ridonin in vitro. Morphological changes of MDA-MB- 231 cells induced by oridonin for 24 h were ob- served by invert microscrope. The cell viability rate was evaluated by MTT assay. The cell ap- optotic rate was evalutated by flow cytometry （FCM）. The apoptosis associated protein level of procaspase-3, PARP,Akt, p-Akt, p-GSK 313 was examined by Western blotting. RESULTS： The apoptosis phenomenon of MDA-MB-231 cells induced by oridonin for 24 h could be ob- served. The apoptosis phenomenon of 24 μmol/ L group was more obvious than other groups.The cell viability rate induced by 6,12,24μmol/ L oridonin was decreased and apoptotic rate was increased in a time- and dose-dependent manner （P〈0.01）. Oridonin cleaved PARP which is the substrate of caspase-3 in a dose-dependent manner（P〈0.05）. Oridonin also down- regula- ted the protein level of procaspase-3, phospho- Akt（p-Akt） and phospho-GSKβ（p- GSK3β） in a dose-dependent manner（P〈0.05）. CONCLU- SION： Oridonin can inhibit the proliferation of human breast cancer MDA-MB-231 cells and in- duce cell apoptosis by inhibiting PI3K/Akt path- way.