Abstract:

Abstract:Objective To explore the potential mechanisms of non-small cell lung carcinoma cells to rsTRAIL protein-induced apoptosis by phosphatidylinositol 3′-kinase (PI3K/Akt) inhibitor LY294002, and to provide new ways to increase killing activities of rsTRAIL protein for non-small cell lung cancer.Methods The A549 cells at logarithmic growth phase were selected and randomly divided into rsTRAIL group and LY294002+rsTRAIL group.The inhibitory rate of  growth of the A549 cells was tested by MTT assay.The cell cycle and apoptotic rate were detected by flow cytometry analysis.The expression levels of Ser473 phosphorylated form of Akt(p-Akt),c-FLIPL protein and Bcl-2 protein in the A549 cells in two groups were analyzed by Western blotting method.Results The inhibitory rate of  growth of the A549 cells in LY294002+rsTRAI group (74.6%±2.63%)was higher than that in rsTRAIL group (5.61%±0.32%) (P<0.05).Compared with rsTRAIL group,the percentage of the cells at G0/G1 phase  in LY294002+rsTRAIL group was increased(P<0.05) and the percentage  of the cells at S phase was decreased(P<0.05).The apoptotic rate of the A549 cells in LY294002+rsTRAIL group (61.5%±3.02%) was higher than that in rsTRAIL group (3.21％±0.96％) (P<0.05). The Western blotting results showed that the expression levels of p-Akt,c-FLIPL  and Bcl-2 proteins in the A549 cells in LY294002+rsTRAIL group were decreased (P<0.05) and the  ratio of Bax/Bcl-2 was increased (P<0.05) compared with rsTRAIL group.Conclusion LY294002 can increase the killing activity of rsTRAIL protein in A549 cells by inhibiting the activity of PI3K.

Key words: cancer non- small cell lung；A549 cells；TNF-related apoptosis inducing ligand； LY294002；PI3K/Akt ,