Effect of Sodium Arsenite on the Expression of Antioxidant Genes (SOD2 and CAT) in MCF-7 and Jurkat Cell Lines

摘要

Background: Sodium arsenite (NaAsO2) has potent cytotoxic activity in human cancer cells. Oxidative stress has been suggested as a mechanism for arsenic-induced carcinogenesis. The purpose of the present study was to evaluate the alteration of mRNA levels of catalase ( CAT ) and superoxide dismutase 2 ( SOD2 ) in MCF-7 and Jurkat cells after exposure to NaAsO 2 . Methods: Methylthiazol tetrazolium (MTT) viability assay was performed to evaluate cytotoxicity of NaAsO 2 in MCF-7 and Jurkat cells. For evaluating the expression levels of the CAT and SOD2 , we used two concentrations of NaAsO 2 (5 and 15 μM), lower than the concentrations at which 50% of cell viability were lost. The cells were treated with co-treatment of NaAsO 2 (15 μM) and N-acetyl-cysteine (NAC; 5 μM) in the media for 24 h. The control cells were maintained in sodium arsenite free growth medium. The experiments were done triplicate. Using quantitative real-time PCR, the expression levels of CAT and SOD2 were quantified. One sample student’s t test was performed for comparisons of mRNA levels between treatment groups and their corresponding untreated control cells. Results: CAT mRNA level decreased significantly in both cell lines following exposure to NaAsO 2 ( P <0.05). Expression levels of SOD2 decreased in Jurkat cells and increased in MCF-7 cells after treatment with NaAsO 2 ( P <0.05). Conclusion: After cells exposure to NaAsO 2 , CAT mRNA level decreased in both examined cell lines but the alterations of SOD2 mRNA level is cell specific. The NAC modulated the NaAsO 2 associated alterations of CAT and SOD2 mRNA levels, therefore, the NaAsO 2 might act through inducing reactive oxygen species.