Down-regulation of vascular endothelial growth factor expression by Kr(u)ppel-life factor 4 overex pression in gastric cancer AGS cells

Abstract

Objective To investigate whether Kruppel-life factor 4 （KLF4） is involved in the regulation of the expression of vascular endothelial growth factor （VEGF） in gastric cancer AGS cells. Methods Human gastric cancer AGS ceils were cultured in vitro and divided into 4 groups ： control group 1 （ transfecting empty plasmid for 24 h） ; control group 2 （ transfecting empty plasmid for 48 h） ; experimental group 1 （transfecting KLF4 expression plasmid for 24 b） ;experimental group 2 （transfecting KLF4 expression plasmid for 48 h）. KLF4 expression plasmids were constructed and transfected into AGS cells using LipofectamineTM 2000. Total RNA and protein were extracted 24 and 48 h after transfeetion. The expression of KLF4 and VEGF mRNA and protein was detected by using real time quantitative RT-PCR and Western blotting respectively. Results As compared with control groups, the expression of KLF4 mRNA and protein was increased significantly in experimental groups （ P 〈 0.05 ）. Correspondingly, the expression of VEGF mRNA and protein was decreased significantly in experimental groups as compared with control groups （ P 〈 0.05 ）. Conclusion Overexpression of KLF4 can down-regulate the VEGF mRNA and protein expression in AGS cells in vitro. KLF4 is likely involved in the down-regulation of VEGF expression in AGS cells. Key words: Gastric carcinoma; VEGF; Nuclear factor