Objective To investigate the suppressing effects of RNA interference (RNAi)targeting AKT1 and phosphatidylinositol 3-kinase p85 (PI3KP85) on the invasion ability of malignant glioma U251 cells in vitro.Methods Normal control group,negative control group (U251 cells being transfected by nonsense sequence of adenovirus) and gene treatment group were chosen in the experiment.A recombinant rctrovims expressing short interference RNA (siRNA) sequence targeting AKTi and PI3KP85 genes was established and transfected into the U251 cells in the gene treatment group.The silencing effect of RNAi on AKTI and PI3KP85 expressions was identified by real time PCR and Westem blotting,respectively.Western blotting was also employed to analyze the expression of some functional proteins.Enzyme-linked immuno sorbent assay (ELISA) was used to detect the changes of concentration of ectocytic matrix metalloproteinases 2 (MMP2) and MMPg.The invasion ability of U251 cells in the 3 groups was evaluated by scarification and Transwell assay.Results The expressions of AKT1 and PI3KP85 in U251 cells in the gene treatment group were dramatically down-regulated.As compared with the normal control and negative control groups,the gene treatment group showed significantly lower expression level of MMP2 and MMP9(P<0.05);meanwhile tissue inhibitor of matrix metalloproteinase-2(TIMP2)in the gene treatment group was significantly up-regulated.ELISA also indicated obvious changes of concentration of ectocytic MMP2 and MMP9.The scarification and Transwell assay showed that the invasion ability in the gene treatment group was significantly decreased as compared with that in the other 2 groups (P<0.05).Conclusion RNAi targeting AKT1 and PI3KP85 can significantly down-regulate the expressions of AKT1 and PI3KP85 and decrease the invasion ability of U251 cells in vitro.