二氢青蒿素对人宫颈癌细胞株照射后周期的影响及相关机制

目的 观察二氢青蒿素及X射线对肿瘤细胞周期的影响,并研究其具体作用机制。方法 选用已知p53突变的人宫颈癌HeLa细胞,并以p53功能正常的人宫颈癌SiHa细胞作为对照。采用流式细胞术分析X射线(6 Gy)、二氢青蒿素(20及100 μmol/L)对两种细胞的细胞周期的影响;应用蛋白印迹法(Western blot)检测细胞周期相关蛋白表达量的变化。结果 X射线照射明显导致HeLa细胞G₂期阻滞,照射后G₂期细胞比例由14.45%上升至73.58%,在二氢青蒿素联合照射作用后,HeLa细胞G₂期细胞比例由单纯照射组的73.58%降至48.31%;而对照组SiHa细胞G₂期变化不明显。在单纯照射组,随着细胞G₂期阻滞的增加,HeLa细胞中Wee1蛋白表达量增加,Cyclin B1蛋白表达量降低,而在二氢青蒿素联合照射作用后,细胞内Wee1蛋白表达量较单纯照射组减少,Cyclin B1蛋白表达量较单纯照射组增高,与该药能去除电离辐射导致细胞G₂期阻滞过程相一致。结论 对于p53突变的人宫颈癌HeLa细胞,二氢青蒿素能抑制辐射所引起的细胞G₂期阻滞,其机理可能与细胞周期调控蛋白Wee1、Cyclin B1表达变化有关;对p53功能正常的SiHa细胞,辐射主要引起细胞G₁期阻滞,故二氢青蒿素对其周期的影响作用不明显。

Effect of dihydroartemisinin on the cell cycle progress of irradiated human cervical cancer cell line and its mechanism

Objective To observe the changes of cell cycle on cancer cells after dihydroartemisinin and X-ray irradiation. Methods Human HeLa cells of cervical cancer with p53 mutation was used and human SiHa cells of cervical cancer with wild p53 was used as control. Flow cytometry was used to detect the effect of dihydroartemisinin (20 and 100 μmol/L) and irradiation (6 Gy)on cell cycle. Western blot was used to measure the levels of cell cycle protein. Results G2 arrest was observed in irradiated HeLa cells, which the proportion of cells in G2 phase was increased from 14.45% to 73. 58% after 6 Gy X-ray irradiation, but it was abrogated by dihydroartemisinin from 73. 58% to 48.31%in HeLa cells, and it had no change on the SiHa cells. The elevated Weel protein and the lowered Cyclin B1 protein were observed with the G2 arrest severity. The expression of radiation-induced Weel protein was suppressed and the Cyclin B1 protein was increased after dihydroartemisinin treatment, which was in accordance with the abrogation of radiation-induced G2 delay. Conclusions The main effect of irradiation on cell cycle of p53 mutated HeLa cells is G2 arrest. Dihydroartemisinin could abrogate it, which is associated with the changes of Weel protein and Cyclin B1 protein. In Siha cells, the main effect of irradiation on cell cycle is G1 arrest, and dihydroartemisinin has no effect on it.