抑制HSP90对缺氧肿瘤细胞辐射敏感性的影响

The effect of inhibition HSP90 on radio-sensitization of hypoxic cancer cells

为研究抑制HSP90对缺氧模拟剂(CoCl2)处理的人宫颈癌Hela细胞的辐射敏感性影响,分别用不同浓度的CoCl2处理Hela细胞24 h进行模拟缺氧处理,用不同浓度的HSP90特异性抑制剂17-DMAG预处理细胞16 h,应用γ射线照射细胞,照射剂量分别为2、4、6和8 Gy,采用克隆形成实验观察细胞的存活率,用Western blot实验检测HIF-1α蛋白表达量变化,用激光共聚焦显微镜观察细胞凋亡情况。结果显示:用CoCl2处理细胞可以诱导HIF-1α蛋白过表达;不同浓度17-DMAG处理组的Hela细胞在不同照射组间的存活率差异具有显著性(p<0.01);17-DMAG预处理缺氧Hela细胞后,HIF-1α蛋白表达随药物浓度增加受到显著抑制,细胞早、晚期凋亡率随药物浓度增加而增加。结果表明:17-DMAG预处理模拟缺氧细胞可增加细胞辐射敏感性并促进细胞凋亡,其机制可能是通过抑制HIF-1α蛋白表达而发挥作用。

To investigate the radio-sensitization impact of 17-DAMG on hypoxic human Hela cells, CoC12 with different concentration was used to treat the cells for 24 h, then the cells were exposed to 17-DAMG of different den- sity for 16 h and irradiated with different doses of 2, 4, 6, 8 Gy γ-rays. The HIF-1a protein level was determined by Western blot analysis, the radiation-sensitization was detected by cloned assay and the Laser Confocal Scanning Mi- croscope was used to test cell apoptosis. The results showed that the HIF-1α protein was over-expressed when the concentration of CoC12 was set at 200 μmol/L, the cell survival rate was significant decreased （p〈0.01） when Hela cells were cultured in different concentration of 17-DAMG and exposed to different doses irradiation; After 17-DAMG pretreatment HIF-lu protein expression was inhibited significantly and the apoptosis rate of hypoxic Hela cells in early and late stages significant increased with the increment of drug concentration （p〈0.01）. The results indicate that 17-DAMG pretreatment can improve the radio-sensitization of hypoxic Hela cells through the cell apoptosis as HIF-lct protein expression can be inhibited byl 7-DAMG.