Abstract: Objective To investigate the effect of sodium arsenite on nuclear factor-erythroid 2-related factor 2(NRF2) activity in human uroepithelial cells (SV-HUC-1).Methods The SV-HUV-1 cells were treated with 4 μmol/L sodium arsenite (NaAsO₂) for 0 (control group),4,8,16,and 24 hours for time-effect evaluation and the treatments of 16 hours with NaAsO₂ of 1,2,4,8 and 10 μmol/L were adopted for dose-response assessment.NRF2 pathway related proteins (NRF2,NAD(P) H-quinone oxidoreductase 1NQO1 and heme oxygenase-1HO1)were detected with Western blot.Results The NRF2 protein levels were significantly increased in the SV-HUC-1 cells after exposed to 4 μmol/L NaAsO₂ for 4,8,16,and 24 hours compared to that in the control cells (0.68±0.03) and the maximum NRF2 protein level (1.17±0.10) was observed in the cells treated for 16 hours (P<0.05).The protein levels of NRF2,NQO1 and HO1 increased in dose-response manner when treated with various dosages of NaAsO₂ for 16 hours.Compared to the protein levels of NRF2 (0.86±0.05),NQO1 (0.68±0.02),and HO1 (0.09±0.01) in the control group,the levels of NRF2,NQO1,and HO1 increased to 1.12±0.01,1.16±0.11 and 0.93±0.01 and 1.15±0.19,1.28±0.01 and 1.30±0.02 in the cells treated with 4 and 8 μmol/L NaAsO₂,respectively (all P<0.05).Conclusion Acute NaAsO₂ exposure can activate NRF2 pathway and induce adaptive antioxidant response in SV-HUC-1 cells.