双氢青蒿素对Raji细胞放射敏感性的影响

Effects of dihydroartemisinin on radiosensitivity of Raji cells

目的:研究双氢青蒿素(DHA)对Raji细胞放射敏感性的影响并探讨其作用机制。方法:CCK8测定DHA对Raji细胞活力的影响,流式细胞术检测细胞凋亡、胞内ROS及线粒体膜电位,Western blot检测AKT、pAKT、Bcl-2、Bax和Cleaved-Caspase-3蛋白表达量。结果:实验分为对照组、DHA组(5μmol/L DHA)、放射组(4Gyγ射线)、联合放射组(5μmol/L DHA和4 Gyγ射线),与其他3组相比,联合放射组Raji细胞的线粒体膜电位显著降低(P<0.01),胞内ROS含量和凋亡率显著升高(P<0.01);此外,Raji细胞AKT表达量与其他3组相比无明显差异,但AKT的磷酸化受到抑制;Bcl-2表达量显著降低,而Bax、Cleaved-Caspase-3表达量显著升高。结论:DHA可能通过抑制磷酸肌醇3-激酶(PI3K-AKT)信号通路及激活了Raji细胞的线粒体凋亡途径,引起氧化应激反应,从而增加Raji细胞对放射的敏感性。

Objective： To study the effects of dihydroartemisinin （DHA） on radiation sensitivity of Raji cells, and explore its mechanisms. Methods： CCK8 was used to determine the effect of DHA on cell viability of Raji cells; apoptosis, intracellular reactive oxygen speies （ROS） and mitochondrial membrane potential of Raji cells were detected by flow cytometry; and the protein expressions of protein kinase B （AKT）, phospho-rylated-protein kinase B（p-AKT）, Bcl-2 and Bax were determined by Western blot. Results： The cells were randomly divided into four groups： control group, DHA（5μmol/L DHA）, irradiation（IR, 4 Gy）, IR ＋ DHA group （4 Gy IR ＋ 5 μmol/L DHA）. Compared with the other three groups, cells in DHA ＋ IR group exhibited lower mitochondrial membrane potential （ P 〈 0.01）. While the intracellular ROS content and apoptosis rate of Raji cells in DHA ＋ IR group were increased significantly（ P 〈 0.01）. In addition, compared with the other three groups, there was no significant difference in the expression of AKT, but the phosphorylation of AKT protein were significantly inhibited and the expression of Bcl-2 protein was markedly decreased. However, the expressions of Bax and Cleaved-Caspase-3 protein were markedly increased. Conclusion： DHA might activate the mitochondrial apoptotic signal via inhibiting phosphoinositide 3-kinase （PI3K/AKT） pathway and increase oxidative stress to enhance the radiosensitivity of Raji cells.