Experiment Study On Down-regulation Of Vascular Endothelial Growth Factor In Human Lung Adenocarcinoma Cell Lines By Rosiglitazone

Objective To explore the effect of a peroxisome proliferators-activated receptor gamma ligand,Rosiglitazone(RSG) on angiogenesis in human lung adenocarcinoma cells via the regulation of vascular endothelial growth factor (VEGF).Methods Human lung adenocarcinoma A549 cell line was cultured in vitro, expression of VEGF protein in A549 lung adenocarcinoma cells treated with Rosiglitazone or without was examined by immunohistochemical staining. Semi-quantitative .RT-PCR examined expression of mRNA of PPARγand VEGF.ResultsImmunohistochemical staining showed that Rosiglitazone had a potent inhibitory effect on the expression of VEGF in A549 cells,in dose dependent manners,Integrated optical density of 1.25,2.5,5.0,10,20,100μmol.L-1RSG group was 2381.32±151.16,1794.18±142.25,938.26±121.32,645.43±136.11,861.31±124.17,2574.64±154.21, respectively. among which the effects of 10μmol.L-1RSG group get to maximum,that of upwards of 20μmol.L-1RSG was relatively weaken,whereas 100μmol.L-1RSG group did not have this down-regulation(P>0.05 n=6);the effect of 10μmol.L-1RSG group had an obvious advantage with that of 100ng.ml-1TNP-470 group ;GW9662 ,a PPARγantagonist blocked in partly this effects of Rosiglitazone.RT-PCR showed that PPARγmRNA was enhanced in cells treated with Rosiglitazone, compared with those of untreated cells, in a dose-dependent manner(P<0.01 or p<0.05.n=6), relative density percentage of 1.25,2.5,5.0,10,20,100μmol.L-1RSG group was 79.75±6.45,90.29±4.87,90.50±5.07,103.22±7.52,119.65±9.32,148.51±11.27 respectively. RT-PCR also showed that Rosiglitazone had a potent inhibitory effect on the expression of VEGF in A549 cells,in dose dependent manners,relative density percentage of 1.25,2.5,5.0,10,20,100μmol.L-1RSG group was 68.82±9.49,56.53±3.53,48.57±2.95,16.74±0.93,49.56±4.97,75.63±5.45,respectively. among which the effects of 10μmol.L-1RSG group get to maximum,that of upwards of 20μmol.L-1RSG group was relatively weaken,whereas 100μmol.L-1RSG group did not have this down-regulation(P>0.05 n=6);the effect of 10μmol.L-1RSG group had an obvious advantage with that of 100ng.ml-1TNP-470 group;GW9662 ,a PPARγantagonist blocked in partly this effects of Rosiglitazone.Conclusions1. PPARγand VEGF are overexpression in A549 cells cultured in vitro.2. Rosiglitazone enhanced the expression of PPARγin A549 cells,in a dose dependent manner.3. Rosiglitazone had a potent inhibitory effect on the expression of VEGF in A549 cells,in dose dependent manners.4. The possible molecular mechanisms of Rosiglitazone's inhibiting expression of VEGF in A549 cells was modulated by signal transduction pathway.of PPARγ.