The Mechanism Of PTEN Gene Suppressing Proliferation In Line A549 Lung Adenocarcinoma Cells

Objectives:To investigate the negative effect of PTEN gene on proliferation of the lung adenocarcinoma cell line A549 and to discuss the correlation of the negative effect of PTEN gene and the expression of hTERT in A549 cell line.Methods:We studyed the correlation of PTEN and hTERT in groups:blank group,empty plasmid vector pGFP group,wild-type PTEN group,LY294002 group,siRNA PTEN group, siRNA PTEN+LY294002 group, and mutant PTEN. RT-PCR was used to detect PTEN mRNA and hTERT mRNA levels. Western-blot was used to detect protein of PTEN, p-AKT, hTERT.MTT assay and flow cytometry analysis were used to test the cell proliferation, apoptosis rate and cell cycle.Results:(1).The transfection of wild-type PTEN gene inhibited the proliferation and increased the apoptosis rate of A549 (P<0.05),the proliferation and the apoptosis rate of A549 was not changed obviously after the transfection of empty plasmid vector pGFP or mutant PTEN(P>0.05);(2).The expression of p-AKT decreased when wild-type PTEN gene was transfected in A459(P<0.05),not changed obviously when empty plasmid vector pGFP group or mutant PTEN was transfected(P>0.05);(3).The transfection of siRNA PTEN gene increased the proliferation and decreased the apoptosis rate of A549,increased the expression of p-AKT in A549(P<0.05); Treatment with LY294002 significantly inhibited the proliferation and increased the apoptosis rate of A549 cells (P<0.05); (4).The expression of hTERT mRNA and hTERT protein both decreased when wild-type PTEN gene was transfected (P<0.05),and increased when siRNA PTEN was transfected (P<0.05),but not changed obviously when empty plasmid vector pGFP group or mutant PTEN was transfected; The expression of hTERT mRNA and hTERT protein in A549 were significantly down-regulated when treated by LY294002 (P<0.05).Conclusions:Loss of PTEN gene increased the proliferation and decreased the apoptosis rate in A549.The expression of hTERT may be regulated and controlled by PTEN gene,which is important to the proliferation and apoptosis in lung adenocarcinoma.