Regulation on expression of Gankyrin by hepatitis B virus X protein through Wnt/β-catenin signaling

Abstract:

Objective：To investigate the effects of HBX on Gankyrin expression and role of Wnt/β-catenin signaling pathway in the regulation of HBX on Gankyrin. Methods：HBX adenovirus vector Ad-HBX-GFP was transfected into human hepatocellular carcinoma cell line HepG2，SMMC-7721 cells and Si-HBX molecules was transfected into HepG2 2.15 cells with LipofectamineTM 2000. Expres－sions of HBX and Gankyrin were detected by RT-PCR and Western blot. β-catenin adenovirus vector was transfected into HepG2 and SMMC-7721 cells，and expressions of β-catenin and Gankyrin were detected by Western blot. HBX was overexpressed in β-catenin silenced HepG2 and SMMC-7721 cells，and expressions of β-catenin and Gankyrin were detected by Western blot. Results：①Expres－sions of Gankyrin were higher in HepG2.2.15 cells than in HepG2 cells（P＜0.05）. ②mRNA and protein expressions of Gankyrin were increased significantly in Ad-HBX-GFP group than in Ad-GFP group in HepG2 and SMMC-7721 cell line（P＜0.01）. ③mRNA and protein expressions of Gankyrin were decreased significantly in Si-HBX group than in Si-NC group in HepG2.2.15 cells（P<0.05）. ④Protein expressions of β-catenin were increased significantly in Ad-HBX-GFP group than in Ad-GFP group after overexpressing HBX protein in HepG2 and SMMC-7721 cell line（P＜0.01）. ⑤Protein expressions of Gankyrin were increased significantly in Ad-HBX-GFP group than in Ad-GFP group after overexpressing β-cateninin HepG2 and SMMC-7721 cell line（P＜0.01）. ⑥Protein ex－pressions of Gankyrin were not increased in Ad-si-β-catenin-RFP group than in Ad-RFP group after silencing β-catenin in HepG2 and SMMC-7721 cell line and overexpressing HBX gene（P＜0.01）. Conclusion：HBX-Wnt/β-catenin-Gankyrin signal transduc－tion pathways are existed in hepatocarcinogenesis. Inhibiting the function of β-catenin can interrupt the up-regulation of Gankyrin by HBX，which may provide a new treatment method for hepa－tocellular carcinoma.