Abstract: Objective To investigate the role of PI3K/AKT pathway on growth and invasion effect in human glioma cells U251 by Ad-PTEN and phosphatidylino-sitol 3-kinase inhibitor LY294002.Methods Western blotting analysis was used to detect the PTEN、PI3K and AKT protein expression after LY294002 and Ad-PTEN were transfected into glioma cell lines U251.Flow cytometry,Annexin V/FITC methods,MTT methods were used to detect the proliferative activitity of the U251 cells.The invasion of U251 cells in vitro was examined by Scrath assay and Transwell cell invasion test.The difference between the combined therapy group and the single LY294002 therapy group was also examined.The downstream protein expression in PI3K/AKT signal pathway were also detected by Western blotting.Results The protein expression of PTEN in combined group were significantly higher,while PI3K、AKT(p-ser473)was significantly lower than that in the other three groups(P＜0.05).After treating,the cells in combined group were inhibited at G₀/G₁ phase,and the cell number decreased at S phase.The apoptosis rate in combined group was higher than that in DMSO、Ad-nonsense and LY294002 group.As compared with DMSO、Ad-nonsense and LY294002 group,the cell multiplication rate in combined group presented decreasing trend since the second day in culture(P＜0.05).The invasion and migration cells in combined group was lower than that in other three groups.The protein expression of PCNA、CyclinD1、Bcl-2、NF-κB、MMP-2、MMP-9、and FAK was significantly lower than that in the other three groups(P＜0.05).Conclusion The combined therapy of Ad-PTEN and LY294002 plays a synergistic role in inhibiting the proliferation and invasion of U251 cells.