TRAF2 Represses The Migration Of Hepatocarcinoma Cells Through TGF-β Signaling Pathway

Aims: TGF-β signaling pathway has been proved to be associated with progression of multiple cancers.It plays different roles combining with different proteins.Our study is aimed to prove that if TGF-β signaling pathway could regulate the migration of hepatocarcinoma cells mediated by TRAF2.Methods: 1.Adding 10ng/ml TGF-β to normal huh7 cells and dealing different times.Measuring the relative expression of gene TRAF2.2.Knocking down gene TRAF2 with lenti-virus in huh7 cells.Then put it as experiment group(Sh-TRAF2).Normal huh7 cells or huh7 cells infected by scramble(Sh-NC)are for control group.Both two groups are treated with 10ng/ml TGF-β for same dose and same time.Then applying to(1)Scratch assay;(2)Measuring the expression of transduction proteins in TGF-β signaling pathway by western blot;(3)Measuring interactions of proteins by co-immunoprecipitation..Results: 1.The expression of TRAF2 decreases with time increases in normal huh7 cells treated with TGF-β.2.In scratch assay,Sh-TRAF2 cells migrate a little faster than normal huh7 cells without TGF-β.And Sh-TRAF2 cells migrate much faster than normal huh7 cells when treated with TGF-β.3.Compared with Sh-NC cells,the expression of P-SMAD3 decreases in Sh-TRAF2 cells treated with TGF-β.The expression of SMAD3 and other proteins don’t make difference.4.Co-immunoprecipitation shows that TRAF2 doesn’t combine with SMAD3 directly.Conclusions: 1.TGF-β represses the expression of TRAF2.2.TRAF2 represses cell migration mediated by TGF-β.3.TRAF2 regulates SMAD signaling pathway,promoting phosphorylation of SMAD3.It doesn’t have effect on non-SMAD signaling pathway.4.TRAF2 doesn’t interact with SMAD3 directly.