氡与亚砷酸钠致人永生化上皮细胞DNA损伤的联合毒作用

DNA damage in HBE cells induced by radon in combination with sodium arsenite

目的 探讨氡与亚砷酸钠联合染毒对人永生化上皮（HBE）细胞的DNA损伤作用。方法 以HBE细胞为研究对象,将HBE细胞暴露于20 000 Bq/m3氡浓度、不同时间（0～75 min）和不同浓度（0～50 000 μmol/L）亚砷酸钠以及联合作用,采用活细胞计数试剂盒（CCK-8）检测细胞存活率。通过中效原理,计算氡不同暴露时间和亚砷酸钠不同浓度联合作用联合指数（combination index,CI）。以不同染氡时间（20 000 Bq/m3,10、20和40 min）和不同亚砷酸钠浓度（1.5、3.0和6.0 μmol/L）处理HBE细胞,应用单细胞凝胶电泳法（SCGE）检测氡、亚砷酸钠单独及联合染毒后HBE细胞的DNA损伤情况。结果 氡与亚砷酸钠单独或联合作用对HBE细胞均有抑制作用;氡不同暴露时间和亚砷酸钠不同浓度联合作用的联合指数CI=0.41,表明二者呈现协同作用。与对照组相比,染氡各组HBE细胞的尾部DNA百分含量、尾矩和Olive尾矩均显著增加（t=12.90～23.61,8.81～21.39,18.46～38.97,P〈0.05）;亚砷酸钠染毒各组HBE细胞的尾部DNA百分数、尾矩和Olive尾矩均显著增加（t=18.46～39.67,17.41～27.42,28.03～46.32,P〈0.05）,呈现剂量效应关系。氡与亚砷酸钠联合染毒后DNA损伤存在交互作用（F尾部DNA百分含量=76.07,P〈0.01;F尾矩=290.51,P〈0.01;FOliver尾矩=273.46,P〈0.01）。结论 氡与亚砷酸钠联合染毒对HBE细胞的DNA损伤可产生协同作用。

Objective To study DNA damage effect of radon in combination with sodium arsenite on HBE cells.Methods The HBE cells were exposed to various concentrations of radon （20 kBq/m3, 0-75 min）, sodium arsenite （0-50 mmol/L） and their combinations. Cell viability was tested by cell counting kit-8 （CCK-8）. The combination index （CI） was calculated by different time exposed radon combined with different concentrations sodium arsenite. Single cell gel electrophoresis （SCGE） was applied for quantitative analysis of DNA damage. Results Radon with or without sodium arsenite inhibited the growth of HBE cells. Computed using median-effect principle, CI=0.41 indicated that radon and sodium arsenite had synergistic effect. Radon and sodium arsenite both could significantly increase tail DNA, tail moment and olive tail moment of HBE cells in SCGE compared with control （t=12.90-23.61,8.81-21.39,18.46-38.97,P〈0.05; t=18.46-39.67,17.41-27.42,28.03-46.32,P〈0.05）. There was a dose-response relationship between radon level, sodium arsenite and DNA damage. The results of factorial analysis showed that there was a combination effect of DNA damage induced by radon and sodium arsenite （Ftail DNA%=76.07,P〈0.01;Ftail moment=290.51,P〈0.01;FOliver tail moment=273.46,P〈0.01）. Conclusions There is a synergistic effect of DNA damage in HBE cells irradiated by radon in combination with sodium arsenite.