A Primary Study On Mechanisms Of Biological Behaviorchanges In Gastric Cancer Cells Induced By Epstein-Barr Virus-Encoded BARF1 Gene Through Activating Wnt/B-Catenin Signaling Pathway

Objective To explore the influence on changes of biological behaviour and related gene expression,and the effect of Wnt/β-catenin signaling pathway in gastric cancer cells by EBV-encoded BARF1 gene.Methods1) Cell reproductive activity and cell cycle were respectively analysed using cell counting and flow cytometry in pSG5-BARF1 recombinant plasmid stablely transfected SGC-7901 cells(SGC-BARF1) under the control of vacant vector transfected cells(SGC-pSG5).Cell apoptosis induced by paclitaxel were detected by cell survival test and DNA ladder in agarose electrophoretic analysis.2) Expression of bcl-2,cyclin D1,c-myc and c-met in mRNA and protein levels in SGC-BARF1 and SGC-pSG5 cells were analysed by Real-time fluorescence quantitive PCR and immunoblotting assay.3) The level ofβ-Cat,GSK3β,phosphrylated GSK3βproteins in SGC-BARF1 and SGC-pSG5 cells were analysed by immunoblotting assay.4) The level ofβ-Cat,GSK3β,Cyclin D1 and c-Myc proteins in specific inhibitor of PI3-K LY294002 treated and untreated SGC-BARF1 and SGC-pSG5 cells were analysed by immunoblotting assay.Results1) Compared with SGC-pSG5 control cells,the cell proliferation ability,the proportion of the cells in S phase,and the resistance to apoptosis induced by paclitaxel in SGC-BARF1 cells is significantly increased(p＜0.01).2) Compared with control cells,the expression of bcl-2,cyclin D1,c-myc and c-met in both of mRNA and protein levels were significantly increasd in SGC-BARF1 cells(p＜0.05).3) Compared with control cells,β-Cat protein in cytoplasms and nuclei, phosphorylated GSK3βprotein in nuclei were increased,and GSK3βprotein in cytoplasms was decreased in SGC-BARF1 cells.4)β-Cat,Cyclin D1 and c-Myc proteins were decreased and G SK3βprotein was increased in LY294002 treated SGC-BARF1 cells,but not changed in SGC-pSG5 control cells.Conclusion EBV-encoded BARF1 gene changes cell biological behavior by upregulating the related gene expression such as bcl-2,cyclin D1,c-myc and c-met through activativing Wnt/β-catenin signaling pathway via PI3-K in gastric epithelial cells.