Objective: To investigate the effect of chronic exposure to sodium arsenite at a dose of 1. 0 μmol / L on proliferation of human bronchial epithelial cells( HBE) and human keratinocytes( HaCaT) and discuss the mechanism of arsenic carcinogenesis.
Methods: Malignant transformation model of HBE and HaCaT cells cultured in vitro were used in this study. MTT assay was used to detect the capacity of proliferation. Flow cytometry was used to detect cell cycle. The expression of cell cycle related protein like cyclin E, cyclin D1 and cyclin A protein were inspected by Western blot.
Results: The treated cells, including passage 36 and 43 of HBE cells and passage 28 and 35 of HaCaT cells grow faster than the control group( P < 0. 01 and P < 0. 05). The treated cells in the G1 phase were decreased( P < 0. 05), however cells in the S phase were increased( P <0. 05). In addition, the expression of cyclin E displayed a trend of up-regulation( P <0. 05), and it was maintained at a high level in advanced period.
Conclusion: By increasing the expression of cyclin E in HBE and HaCaT cells, low dose of sodium arsenite made cells escaping from the G1 phase to S phase, accelerating cell cycle progression and proliferation, a way that may lead to malignant transformation.
Keywords: cell cycle; cell proliferation; cyclin E; sodium arsenite.