ERK1/2-Sp1信号通路对肺癌细胞VEGF的调控作用

Role of ERK1/2-Sp1 in Regulation of VEGF Expression in Lung Cancer Cells

背景与目的:了解ERK1/2-Sp1信号通路对肺癌细胞血管内皮生长因子(VEGF)基因的调控作用。材料与方法:采用激酶特异抑制剂PD98059抑制ERK1/2的活性,Western blot检测ERK1/2的表达。RNA干扰技术沉默Sp1基因,Mercury信号通路系统检测Sp1的转录活性。RT-PCR检测VEGF和Sp1基因的变化。结果:ERK1/2激酶的活性几乎可被150μmol/L PD98059完全抑制,ERK1/2激酶活性下调伴随VEGF的表达下降。PD98059下调Sp1转录因子的活性。Sp1基因沉默后VEGF的表达量下调。结论:在肺癌细胞中存在ERK1/2-Sp1-VEGF信号通路,ERK1/2激酶调控VEGF的表达可能部分依赖于转录因子Sp1的活性。

BACKGROUND ＆ AIM： To study the underlying molecular mechanisms by which ERK1/2 kinase modulated the expression of vascular endothelial cells growth factor （VEGF） in lung cancer cells. MATERIALS AND METHODS： PD98059, the special inhibitor of ERK1/2, was used to inhibit the phosphorylation of ERK1/2. Western blot was used to evaluate the expression of ERK1/2. Transcription factor Sp1 gene was silenced by small interfering RNA technology. SEAP assay was used to detect the transcription activity of Sp1. RT-PCR was applied to examine the expression status of VEGF and Sp1. RESULTS： Western blot and RT-PCR results proved that PD98059 inhibited the phosphorylation of ERK1/2. The expression of VEGF gene was decreased associated with the inhibition of ERK1/2 kinase. The transcription activity of Sp1 was down-regulated by PD98059. SiRNA targeting Sp1 effectively decreased the expression of itself and VEGF. CONCLUSION：In lung cancer cells the expression of VEGF might be regulated by ERK1/ 2 signal pathway, and partly depended on the activity of transcription factor Sp1.