[DNA依赖性蛋白激酶在二氧化硅诱导人胚肺成纤维细胞周期蛋白E和细胞周期蛋白依赖性激酶2表达及细胞周期变化中的作用]

[Roles of DNA dependent protein kinase in silica-induced cyclin E and CDK2 expressions and cell cycle changes in human embryo lung fibroblasts].

作者信息

Liu Hai-Feng, Zhang Feng-Mei, Liu Bing-Ci, Jia Xiao-Wei, Ye Meng

机构信息

National Institute of Occupation Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing 100050, China.

出版信息

Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi. 2011 Apr;29(4):241-5.

PMID:21941773

Abstract

OBJECTIVE

To study the roles of DNA dependent protein kinase (DNA-PK)in silica-induced cell cycle changes and expressions of CyclinE and CDK2 in human embryo lung fibroblasts (HELF).

METHODS

The expressions of Ku80 and DNA-PKcs proteins were inhibited by siRNA plasmids, respectively. Flow cytometry was used to detect the distributions of cell cycle and western blot assay was used to determine the expression levels of CyclinE and CDK2 after cells were exposed to 200 microg/ml silica for 0, 3, 6, 12, 24 h.

RESULTS

The proportion of G1 phases in negative control cells decreased from 83.53% +/- 2.24% to 69.11% +/- 3.12% after exposure to silica; the proportion of G1 phases in H-Ku80 and H-PKcs cells exposed to silica decreased from 85.16% +/- 3.73% to 59.92% +/- 3.31% and from 75.06% +/- 2.23% to 58.32% +/- 1.35%, respectively (P < 0.05). The exposure to silica resulted in the increasing protein expression levels of CyclinE and CDK2 in negative control cells, and the expression levels of CyclinE were obviously suppressed in H-Ku80 and H-PKcs as compared with control cells. However, the expression level of CDK2 protein did not change significantly.

CONCLUSION

DNA-PK might play a role in silica-induced alternations of cell cycle and regulate silica-induced overexpression of CyclinE in human embryo lung fibroblasts.

摘要

目的

研究DNA依赖性蛋白激酶（DNA-PK）在二氧化硅诱导人胚肺成纤维细胞（HELF）细胞周期变化及细胞周期蛋白E（CyclinE）和细胞周期蛋白依赖性激酶2（CDK2）表达中的作用。

方法

分别用小干扰RNA（siRNA）质粒抑制Ku80和DNA-PKcs蛋白的表达。细胞暴露于200μg/ml二氧化硅0、3、6、12、24小时后，采用流式细胞术检测细胞周期分布，蛋白质印迹法检测CyclinE和CDK2的表达水平。

结果

阴性对照细胞暴露于二氧化硅后，G1期比例从83.53%±2.24%降至69.11%±3.12%；暴露于二氧化硅的H-Ku80和H-PKcs细胞中，G1期比例分别从85.16%±3.73%降至59.92%±3.31%，从75.06%±2.23%降至58.32%±1.35%（P<0.05）。暴露于二氧化硅导致阴性对照细胞中CyclinE和CDK2蛋白表达水平升高，与对照细胞相比，H-Ku80和H-PKcs细胞中CyclinE的表达水平明显受到抑制。然而，CDK2蛋白的表达水平没有明显变化。