过表达核转录因子Kr(u)ppel样因子4下调胃癌AGS细胞血管内皮生长因子的表达

目的 观察过表达核转录因子Kr(u)ppel样因子4(KLF4)是否下调胃癌AGS细胞血管内皮生长因子(VEGF)的表达.方法 体外培养人胃癌AGS细胞,分为4组:转染空质粒24 h对照组、转染空质粒48 h对照组、转染KLF4表达质粒24 h组、转染KLF4表达质粒48 h组.构建KLF4表达质粒,脂质体LipofectamineTM2000分别转染空质粒、KLF4表达质粒到AGS细胞,24、48 h后提取总RNA和蛋白,实时荧光定量逆转录-聚合酶链反应(RT-PCR)法、Western blot法分别检测KLF4和VEGF mRNA和蛋白水平的表达.结果 AGS细胞在24 h转染率为65%-75%,48 h转染率为40%～45%.实验组与对照组转染24、48 h后,KLF4 mRNA的表达量分别为:563.584±250.744比4.997±5.729(P＜0.05);351.852±212.439比2.4420±1.3770(P＜0.05).VEGF mRNA表达量分别为:0.008 929±0.003 810比0.002 294±0.000720(P＜0.05);0.018 375±0.008 263比0.002 193±0.001 698(P＜0.05);胃癌AGS细胞KLF4蛋白表达量显著性增加,相对应地VEGF蛋白表达水平显著性降低(P＜0.05).结论 体外胃癌AGS细胞过表达KLF4导致VEGF mRNA和蛋白表达下调,KLF4可能参与抑制调节胃癌AGS细胞VEGF的表达.

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

Objective To investigate whether Krtippel-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 cells were cultured in vitro and divided into 4 groups:control group 1(transfecting empty plasmid for 24 h);control group 2(transfeeting empty plasmid for 48 h);experimental group 1(transfecting KLF4 expression plasmid for 24 h);experimental group 2(transfecting KLF4 expression plasmid for 48 h).KLF4 expression plasmids were constructed and transfeeted into AGS cells using LipofeetamineTM 2000.Total RNA and protein were extracted 24 and 48 h after transfection.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 call 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.