Effects Of Hepatitis C Virus Core Protein And NS4B On The Expression Of Wnt1,β-catenin,c-myc And CyclinD1in HepG2Cells

Objective：To investigate the effects of hepatitis C virus(HCV) core protein（C） andnonstructural protein4B(NS4B) on the expression of Wnt1,β-catenin,c-myc andCyclinD1in HepG2cells; to explore the relationship between HCV core protein,NS4B and cell proliferation, and its possible mechanism.Methods：The recombination vectors of HCV1b type core protein（pcDNA3.1(-) C）andNS4B（pcDNA3.1(-) NS4B）were transfected respectively and co-transfected intoHepG2cells by lipofectamine, simultaneously HepG2cells transfected withpcDNA3.1(-) and untransfected HepG2cells were used as control. The expressions ofmRNA and protein of HCV C or NS4B were detected by RT-PCR and Western blotrespectively. And then, the expression levels of mRNA and protein of Wnt1,β-catenin,c-myc and CyclinD1in the cells of each group were detected by RT-PCR andWestern blot respectively. The growth curve was made by MTT, to observe the effectsof HCV C and NS4B on the growth of HepG2cells. Flow cytometry was used todetermine cell cycle.Results：1. The recombination vectors pcDNA3.1(-) C and pcDNA3.1(-) NS4Btransiently transfected respectively or co-transfected into HepG2cells, then, HCV Cor NS4B were expressed successfully in the HepG2cell line.2. Relative levels of mRNA and protein of Wnt1, β-catenin, c-myc andCyclinD1were higher in the cells of Groups pcDNA3.1(-)C, pcDNA3.1(-)NS4B andpcDNA3.1(-)C+pcDNA3.1(-)NS4B than those in the cells of Group pcDNA3.1(-) and Group blank control(p<0.01); while among the cells of Groups pcDNA3.1(-)C,pcDNA3.1(-)NS4B and pcDNA3.1(-)C+pcDNA3.1(-)NS4B, two of them compared,there were not significantly different(P>0.05); also there were no significantdifferences between the cells of Group pcDNA3.1(-) and the cells of Group blankcontrol(P>0.05).3. At one to four days after the trasfection, the rate of cells growth were fasterin Groups pcDNA3.1(-)C, pcDNA3.1(-)NS4B and pcDNA3.1(-)C+pcDNA3.1(-)NS4B than those in the Group pcDNA3.1(-) and Group blank control(p<0.01), while therate of cells growth between the other groups were no significant differences(P>0.05).4. The levels of Go/GIphase were lower in the Groups pcDNA3.1(-)C,pcDNA3.1(-)NS4B and pcDNA3.1(-)C+pcDNA3.1(-)NS4B than those in the GrouppcDNA3.1(-) and Group blank control(p<0.01), but the rate of S phase or G2/M phasewere significantly higher in the Groups pcDNA3.1(-)C, pcDNA3.1(-)NS4B andpcDNA3.1(-)C+pcDNA3.1(-)NS4B than that in the Group pcDNA3.1(-) and Groupblank control(p<0.01). In addition, the cells of Go/GIphase, S phase or G2/M phaseamong the remaining groups were not significantly different (P>0.05).Conclusion：1. HCV core protein and NS4B can up-regulate the expression of Wnt1, β-catenin, c-myc and CyclinD1in HepG2cells, which were the upstream anddownstream genes of Wnt/β-catenin signaling pathway.2. Wnt/β-catenin signaling pathway were activated, which maybe one of themechanisms of HCV core protein and NS4B to accelerate cells cycle and promote theproliferation of cells.