齐墩果酸联合放疗对HepG2细胞周期和凋亡作用的体外研究

目的体外观察齐墩果酸(oleanolic acid,OA)联合放疗对肝癌HepG2细胞周期和凋亡的影响,探讨OA的放射增敏作用及其机制.方法对数生长期HepG2细胞分为对照组、单纯给药组(OA组)、单纯照射组(IR组)、照射与药物联合作用组(IR+OA组).MTT法检测细胞活力,Hoechst33258染色观察细胞凋亡形态学变化,流式细胞仪检测细胞周期和凋亡,Western blotting检测细胞周期相关蛋白表达.结果 OA显著增加射线的杀伤作用,联合组细胞的活力明显下降,凋亡率增高,细胞周期蛋白CyclinB1和Cdk1的降低,p-Cdk1表达量上升更明显,细胞G2/M期阻滞明显高于对照组(P0.05).结论 OA显著增加射线对肝癌细胞的杀伤作用,其机制可能与CyclinB1-Cdk1复合物的表达量减少和活性抑制、诱导细胞阻滞G2/M期有关.

Effects of Oleanolic Acid Combined with Radiotherapy on HepG2 Cell Cycle and Apoptosis in Vitro

Objective To observe the effect of oleanolic acid ( OA) combined with radiotherapy on the cell cycle and apoptosis of hepatocellular carcinoma HepG2 in vitro, and to explore the radiosensitizing effect and its mechanism of OA. Method The HepG2 cells in logarithmic growth phase were divided into the control group, simple administration group ( OA group) ,simple irradiation group ( IR group) ,irradiation and drug combination group ( IR+OA group ) . Cell viability was detected by MTT assay, apoptosis morphology was observed by Hoechst33258 staining,cell cycle and apoptosis were detected by flow cytometry,and cell cycle-related protein expression was detected by Western blotting. Results OA significantly increased the killing effect of radiation. Compared with the control,the viability of the cells in the combination group significantly decreased,the apoptosis rate increased, the expressions of CyclinB1 and Cdk1 decreased, and the expression of p-Cdk1 significantly increased,and the cell G2/M arrest was significantly higher (P<0. 05). Conclusion OA can significantly increase the killing effect of rays on hepatoma cells,which may be related to the decrease of the expression of CyclinB1-Cdk1 complex,the inhibition of cell activity,and the induction of cell arrest in G2/M phase.