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).