Up-regulation Of Angiopoietin Like 4 (angptl4) Expression In Human Lung Adenocarcinoma Cells Induced By Tgf-β Partly Depending On Hypoxia Inducible Factor Hif-1

【Objective】: To silence the expression of HIF-1αin Human lung adenocarcinoma cell lines A549 by RNA interference, and initially discuss the function of HIF-1 in TGF-β-mediated up-regulation of ANGPTL4 expression.【Method】: The HIF-1α-shRNA and empty plasmids were amplified and purified. Then, they were transfected into the human lung adenocarcinoma cell lines A549. A549 cell lines transfected with HIF-1α-shRNA plasmid(experimental group), A549 cell lines transfected with empty plasmid (negative control group) and the A549 cell lines untransfected with any plasmids were treated with TGF-β1 with the same concentration. Then, we use RT-PCR and Western-blot to examine the mRNA and protein expression levels of HIF-1αand ANGPTL4 in these three groups of cells respectively.【Results】: With the treatment of TGF-β1 for 0, 12, 24 and 48h, the expression levels of mRNA and protein of HIF-1αand ANGPTL4 were significantly different in these three groups (p<0.05), comparison among groups: the mRNA and protein expression levels of HIF-1αand ANGPTL4 were significantly different in negative control group and experimental group (p<0.05), however, there are not any significant differences between blank group and negative control group (p>0.05). When compared within these three groups, there is a significant time-effect correlation between the mRNA and protein expression levels of HIF-1α,ANGPTL4 and the action time of TGF-β1 in all these three groups (p<0.05).【Conclusions】: HIF-1,as an upstream regulator of ANGPTL4,may participate in the TGF-β-Smad signal pathway and mediate the up-regulation of ANGPTL4.