Study On Induction Of Apoptosis In Human Lung Adenocarcinoma Cells By Combinance Rosiglitazone With Cisplatin

Objective To investigate the effect of the ligand of peroxisome proliferator-activated Receptor gamma (PPARγ) Rosiglitazone (ROZ) on induction of apoptosis in lung adenocarcinoma cell and its possible mechanism. METHODS human lung adenocarcinoma A549 cell line was cultured in vitro.A549 cell line was treated with various concentration of ROZ, DDP or both,Cell counting method was used to test the influence of growth curve in A549 cells,The effect of ROZ on the function of Cisplatin (DDP) in inducing apoptosis of A549 was detected by by AO/EB double fluorescence stain and PI staining flow cytometry and cell cycle was analyzed using flow cytometry.The change of PPARγ, NF-κB,Bcl-2 and Bax protein expressions in lung carcinoma cells before and after treatment was observed by western blot.RESULTS Trypan blue exclusion showed that rosiglitazone and DDP were able to inhibit growth of A549 cells accompanied with increasing of concentration and time.1.25,10.0μmol/L rosiglitazone had no cytotoxic toA549 cells. But Rosiglitazone at 1.25μmol/L significantly increased inhibition growth effect of DDP to A549, prolonging A549 cell multiple time from 60.2h to 700.0h,which consistent with growth curve.(2) AO/EB double fluorescence stain and PI staining flow cytometry data showed the apoptosis of A549 cells induced and cell cycle was arrested at G1 stage by ROZ in a concentration dependent manner;ROZ(1.25μmol/L) significantly promoted DDP(1.96,2.8,4.0mg/L)to induce A549 cells apoptosis.(3)As a ligand-dependent transcriptional factor, peroxisome proliferator-activated receptor PPARγwas expressed in A549 cell and PPARγactivation could enhance the function of DDP in inducing apoptosis of A549 cells. Treated with ROZ at the concentration of 1.25μmol?L-1 and DDP at various concentrations (1.96 mg/L, 2.8 mg/L, 4.0 mg/L) A549 cells demonstrated up-regulated expression of PPARγprotein in the nucleus, inhibited expression of NF-κB protein, down-regulated expression of Bcl-2 protein and up-regulated expression of Bax protein, which reduced the rate of Bcl-2/Bax(P<0.01). Blocking PPARγby the selective PPARγantagonist GW9662(2.0μmol/L),which inhibited NF-κB protein expression, down-regulated Bcl-2 protein expression and up-regulated bax protein expression ;which indicates that PPARγis an effector of NF-Κb,Bcl-2 and Bax(P<0.05).CONCLUSION The combination of ROZ and DDP can induce apoptosis of A549 cells and it shows evidently time and dose dependence. Activation of PPARγcan inhibit expression of NF-κB ,Bcl-2 protein and reduce the rate of Bcl-2/Bax, thereby, depress apoptosis hardiness of A549 cells and enhance the function of DDP in inducing apoptosis of A549 cells.