应用单细胞凝胶电泳比较研究砷对人类细胞DNA的损伤

目的：探讨不同细胞对砷的基因毒性反应及其机理，探讨快速，敏感及经济的细胞基因毒性检测方法。方法：应用单细胞凝胶电泳（Single cell gel electrophoresis,SCGE)或彗星试验（comet assay)比较研究，结果；细胞DNA损伤与砷处理量间呈显著的剂量反应关系和时效关系。受试细胞对砷的基因毒性反应的敏感性强弱顺序为：PMA－HL60＞DMSO－HL60＞HL60＞淋巴细胞，人工计数彗星尾分级频数与计算机自动测量慧星尾DNA泳动量的结果完全一致，用非参数Mann-Whitney多变量检验分析彗星尾分级频数的显著性与参数Tukey多变量检验分析量彗星尾DNA泳动量的显著性完全相同，而且不同浓度的砷与5级彗星尾频数的相关性比其与阳性彗星尾总数间的更为显著，结论：微量砷即可引起细胞不同程度的DNA损伤，不同细胞亚群对砷的基因毒性反应不同，SCGE是一个简便，快速，敏感及经济的细胞基因毒性检测方法，可应用于各级水平的环境与人类疾病（砷污染）监测与研究。

Application of single cell gel electrophoresis (SCGE) assay:comparative study of DNA damage induced by arsenic in human cells

Objective　To study the different responses of cells to arsenic-induced genotoxicity and its possible mechanisms.Methods　Single cell gel electrophoresis (SCGE) assay was used to study the arsenic-induced DNA damage in human promyelocytic HL60,DMSO-differentiated HL60 (DMSO-HL60)，PMA-differentiated HL60 (PMA-HL60) and unstimulated human lymphocytes.Results　Significant dose-effect relationship and time-course were found between arsenic exposure and DNA damage in the treated cells.The sequence for the sensitivity of cells to arsenic-induced genotoxicity was obtained as follows.PMA-HL60 > DMSO-HL60 > HL60 > human lymphocytes.A same result was obtained by counting the classes of the comet tail and by measuring the tail moment in human lymphocytes.The same significance was achieved using nonparametric Mann-Whitney multiple comparisons for visual classes of comet tail and parametric Tukey multiple comparisons for Tail moment.A higher correlation was shown between the comet tail of Class 5,than between total positive comet tail,and doses of arsenic.Conclusions　Micromolar amount of arsenic induces DNA damage in human cells.Different populations of cells had different responses to arsenic-induced genotoxicity.SCGE assay is a economic,rapid,sensitive and economic method detecting genotoxicity.It could be applied in all levels of monitoring and study on environmental pollution and human diseases (arsenic pollution).