紫草素对卵巢癌细胞株SKOV3放疗敏感性的影响及相关机制研究

目的:研究紫草素对人卵巢癌细胞株SKOV-3的放射增敏作用,并探讨其可能的作用机制。方法:MTT法检测不同浓度(0、5、10、20、40、80和120 mg/L)紫草素对SKOV-3细胞活力的影响;克隆形成实验检测8 mg/L紫草素联合不同剂量(0、2、4、6和8 Gy)X射线照射对SKOV-3细胞增殖能力的影响。将SKOV-3细胞分为4组:对照组、紫草素组(8 mg/L紫草素处理)、8 Gy组(8 Gy X射线照射处理)和紫草素+8 Gy组(给予8 mg/L紫草素处理48 h后,再进行8 Gy X射线照射处理)。PI染色及流式细胞术检测各组SKOV-3细胞周期的变化;Western blot检测各组SKOV-3细胞p-PI3K和p-AKT的蛋白表达水平。结果:在0～80 mg/L浓度范围内,紫草素浓度依赖性抑制SKOV-3细胞活力(P0.05),IC_(50)为(38.54±0.57) mg/L;紫草素联合放疗处理后的SKOV-3细胞的存活曲线较单独放疗左移,放射增敏比为1.45±0.05。与8 Gy组相比,紫草素+8 Gy组G_2/M期细胞所占比例下降(P0.05),p-PI3K和p-AKT蛋白水平均显著降低(P0.05)。结论:紫草素具有提高人卵巢癌细胞株SKOV-3放射敏感性的作用,其作用机制可能与紫草素缓解X射线引起的G_2/M期阻滞及抑制PI3K/AKT信号通路有关。

Effects and mechanisms of shikonin on the radiation sensitization of human ovarian cancer cell line SKOV-3

Objective: To investigate the radiosensitizing?effect and the underlying mechanism of shikonin on the human ovarian cancer cell line SKOV-3. Methods: The viability of SKOV-3 cells after treating with different concentrations (0,5,10,20,40,8 0 and 120 μg/mL) of shikonin was measured by MTT assay; The survival rate of SKOV-3 cells after treating with different doses(0,2,4,6 and 8 Gy) of x-ray radiotherapy was testet by clone forming assay.The SKOV-3 cells were divided into 4 groups: the Control group (Control group), the Shk group (8μg/mL Shk treatment), the 8 Gy group (8 Gy X-ray radiotherapy treatment) and the Shk + 8 Gy group (8 Gy μg/mL Shk treatment for 48 hours, followed by 8 Gy X-ray radiotherapy treatment). The cell cycle was examined by PI staining using flow cytometry and the phosphorylation of PI3K and AKT levels were analyzed by western blotting in each group. Results: In the ranged of 0-80μg/mL, shikonin decreased SKOV-3 cell viability in a concentration-dependent manner（P<0.05）. The value of IC50 was 38.54±0.57 μg/mL. Compared with radiotherapy alone, the survival curve was markedly shit to the left after shikonin combined radiotherapy（P<0.05）. The value of radiotherapy sensitization ratio (SER) was 1.45±0.05. Moreover, Compared with 8 Gy alone group, the percentage of G2/M phase and the phosphorylation levels of PI3K and AKT were decreased in Shk+8 Gy group（P<0.05）. Conclusion: Shikonin could increase the radiosensitivity of SKOV-3, and the mechanism may be related to attenuat radiation-induced the G2/M phase arrest and inhibition of PI3K/AKT signaling pathway.