二氢青蒿素抑制ATF2磷酸化提高胃癌细胞对5-氟尿嘧啶的敏感性

Dihydroartemisinin Increases Sensitivity of Gastric Cancer Cells to 5-fluorouracil Through Suppression of ATF2 Phosphorylation

目的探讨二氢青蒿素与5-氟尿嘧啶协同抗胃癌效应的机制。方法 MTT实验检测胃癌细胞系BGC-823的细胞活力;流式细胞术检测BGC-823细胞的凋亡;Western blot实验检测BGC-823细胞中ATF2、磷酸化ATF2、Bcl-xl的表达水平及细胞色素c的释放水平和Caspase-3活化水平。结果 5-氟尿嘧啶联合二氢青蒿素对BGC-823的细胞活力抑制率[(67.1±5.5)%]和凋亡诱导率[(37.3±2.9)%]均显著高于5-氟尿嘧啶单治疗组[细胞活力抑制率:(18.9±1.5)%,P<0.05];凋亡诱导率[(9.5±0.9)%,P<0.05]。5-氟尿嘧啶+二氢青蒿素+ATF2质粒组BGC-823的细胞活力抑制率[(26.5±2.1)%]和凋亡诱导率[(14.9±1.1)%]显著低于5-氟尿嘧啶联合二氢青蒿素组(P<0.05)。5-氟尿嘧啶联合二氢青蒿素组的ATF2磷酸化水平和Bcl-xl表达水平均显著低于5-氟尿嘧啶单治疗组,同时5-氟尿嘧啶联合二氢青蒿素治疗组的细胞色素c释放水平及Caspase-3活化水平均显著高于5-氟尿嘧啶单治疗组。结论二氢青蒿素通过抑制ATF2的磷酸化增强5-氟尿嘧啶对胃癌细胞的杀伤活性。

Objective To investigate the synergistic effect and mechanism of dihydroartemisinin on increasing the cytotoxicity of 5-fluorouracil to gastric cancer. Methods MTT assay was performed to test the cell viability of BGC-823. Flow cytometry analysis was performed to detect the apoptosis of BGC-823 cells. Western blot analysis was performed to evaluate the expression of ATF2, phosphorylated ATF2 and Bcl-xl, and the release of cytochrome c, and the activation of caspase-3 in BGC-823 cells. Results Cell viability inhibitory rate（67.1% ±5.5%） and apoptotic rate（37.3% ±2.9%） of BGC-823 cells in 5-fluorouracil plus dihydroartemisinin group was significantly higher than the cell viability inhibitory rate（18.9% ±1.5%, P 0.05） and apoptotic rate（9.5% ±0.9%, P 0.05） of BGC-823 cells in 5-fluorouracil single treatment group. Cell viability inhibitory rate（26.5%±2.1%） and apoptotic rate（14.9%±1.1%） of BGC-823 in 5-fluorouracil ＋dihydroartemisinin ＋ATF2 plasmid group was significantly lower than the cell viability inhibitory rate（67.1%±5.5%, P0.05） and apoptotic rate（37.3%±2.9%, P0.05） of BGC-823 in 5-fluorouracil ＋ dihydroartemisinin group. Phosphorylation of ATF and expression of Bcl-xl in the 5-fluorouracil plus dihydroartemisinin group was significantly lower than that in the 5-fluorouracil group. Meanwhile, the release of cytochrome c and activation of caspase-3 in the 5-fluorouracil plus dihydroartemisinin group was significantly higher than that in the 5-fluorouracil single treatment group. Conclusion Dihydroartemisinin enhanced the cytotoxicity of 5-fluorouracil against gastric cancer through suppression of ATF2 phosphorylation.