氯碘羟喹联合锌离子对人宫颈癌HeLa细胞的放射增敏研究

Radiosensitization of clioquinol and zinc in human cervical cancer cell lines

目的 探讨氯碘羟喹（CQ）联合锌离子（zinc）对人宫颈癌HeLa细胞系的放射增敏作用。方法 将细胞分为对照组、药物组、单纯照射组、药物＋照射组。CCK-8法检测不同浓度氯碘羟喹联合锌离子对HeLa细胞的毒性作用;集落形成实验检测氯碘羟喹联合锌离子对HeLa细胞放射敏感性的影响,依据单击多靶模型拟合剂量-生存曲线,并计算放射增敏参数;流式细胞仪检测HeLa细胞周期与凋亡率;单荧光素酶报告基因法检测核转录因子NF-κB的活性。结果 氯碘羟喹联合锌离子对HeLa细胞的生长抑制作用呈浓度依赖性（F=188.00,P〈0.01）。单纯照射组和药物＋照射组的平均致死剂量（D0）分别为3.16和2.04 Gy,放射增敏比（SER）为1.55。药物＋照射组较单纯照射组相比,G2期阻滞降低（t=10.39,P〈0.05）,24 h凋亡率增加（t=5.64,P〈0.01）,药物＋照射组NF-κB活性降低（t=21.42,P〈0.05）。与对照组比较,药物组NF-κB活性降低（t=12.48,P〈0.05）,单纯照射组NF-κB活性升高（t=6.23,P〈0.05）。结论 氯碘羟喹和锌离子二者联合使用可增加HeLa细胞的放射敏感性,其机制可能与药物去除X射线诱导的G2期阻滞,增加射线诱导的细胞凋亡,以及抑制细胞NF-κB活性有关。

Objective To investigate the radiosensitization effects of the combination treatment of clioquinol （CQ） and zinc on human cervical cell line HeLa in vitro. Methods Cells were divided into the 4 groups： controls, drug, radiation, and combined drug and radiation group. Cytotoxic effect of CQ and zinc on cell viability was determined by CCK-8 assay. Radiosensitization effect of CQ and zinc on HeLa cells was detected by colongenic assay, and the single-hit multi-target model was used to stimulate the dose-response curve of survival and to calculate radiosensitization parameters. The cell cycle and apoptosis of HeLa cells were analyzed with flow cytometry. Luciferase reporter assay was used to study NF-κB activity of HeLa cells. Results The combination of CQ and zinc inhibited cell growth in a dose-dependent manner（F=188.00, P〈0.01）. The mean lethal dose was 3.16 and 2.04 Gy for radiation group and combined drug and radiation group, respectively, and hence the SER was 1.55. Compared with the radiation group, the ratio of G2-phase cells in the combined drug and radiation group decreased（t=10.39, P〈0.05）, the apoptosis rate increased at 24 h post-irradiation（t=5.64, P〈0.01）, and the NF-κB activity decreased（t=21.42, P〈0.05）. Compared to the control group, the NF-κB activity increased in the radiation group（t=6.23, P〈0.05）, but decreased in the drug group（t=12.48, P〈0.05）. Conclusions The combination of CQ and zinc could increase the radiosensitivity of HeLa cells by decreasing the ratio of G2-phase cells, increasing apoptosis and the inhibiting of NF-κB activity.