长期低剂量亚砷酸钠染毒对人支气管上皮细胞和人角质形成细胞增殖的影响

Effect of low-dose exposure to sodium arsenite on proliferation of HBE and HaCaT cells

目的探讨1.0μmol/L亚砷酸钠慢性染毒对人支气管上皮细胞(HBE)和人角质形成细胞(Ha Ca T)体外增殖的改变及其调控机制。方法以体外培养的HBE和HaCaT细胞恶性转化模型为研究对象,应用MTT法检测细胞增殖情况,采用流式细胞仪检测细胞周期改变,利用Western blot检测细胞周期相关蛋白cyclin E、cyclin D1、cylin A蛋白的表达。结果染砷组HBE细胞36代和43代、HaCaT细胞28代和35代相对增殖率均高于传代对照组(P<0.01和P<0.05);细胞周期G1期细胞比例下降(P<0.05),S期细胞比例上升(P<0.05);此外,细胞周期相关蛋白cyclin E表达升高(P<0.05),并在晚期持续性高表达。结论低剂量亚砷酸钠可通过上调HBE和Ha Ca T细胞中cyclin E的表达从而使细胞从G1期逃逸至S期,加速细胞增殖,最终导致细胞发生恶性转化。

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.