title: Hepatitis B virus X protein promotes hepatoma cell invasion and metastasis by stabilizing Snail protein.
abstract: A high incidence of tumor recurrence and metastasis has been reported in hepatocellular carcinoma (HCC) patients with chronic hepatitis B virus (HBV) infection. Although the pathological relevance and significance of hepatitis B virus X protein (HBx) in HBV-associated hepatocarcinogenesis attracted much attention in recent years, the role and molecular mechanism for HBx in hepatoma invasion and metastasis remains poorly understood. In the present study, we found that HBx expression could induce epithelial-mesenchymal transition in hepatoma and hepatic cells. This effect was shown due to stabilized Snail protein through activating the phosphatidylinositol 3-kinase/protein kinase B/glycogen synthase kinase-3β (PI3K/AKT/GSK-3β) signal pathway by HBx expression. Functional studies revealed that HBx expression could enhance hepatoma cell migration and invasion in vitro. Moreover, stable HBx expression could also facilitate intrahepatic and distant lung metastasis of HCC in a nude mice tumor metastasis model in vivo. The correlation between increased PI3K/AKT/GSK-3β signaling with elevated Snail protein level was also observed in HCC tumor tissues with intrahepatic metastasis or chronic HBV infection. These results revealed a novel function of HBx in promoting epithelial-mesenchymal transition through Snail protein stabilization by activating PI3K/AKT/GSK-3β signaling, thus facilitating tumor invasion and metastasis during HCC progression. This could provide a putative molecular mechanism for tumor recurrence and metastasis in HBV-associated HCC patients.
authors.affiliation: Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Haiou
authors.initials: H
authors.lastname: Liu
authors.forename: Le
authors.initials: L
authors.lastname: Xu
authors.forename: Hongyong
authors.initials: H
authors.lastname: He
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhu
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.forename: Shanshan
authors.initials: S
authors.lastname: Wang
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.forename: Qian
authors.initials: Q
authors.lastname: Wu
authors.forename: Jiejie
authors.initials: J
authors.lastname: Xu
authors.forename: Jianxin
authors.initials: J
authors.lastname: Gu
mesh_terms: D064413:3-Phosphoinositide-Dependent Protein Kinases; D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D002465:Cell Movement; D058750:Epithelial-Mesenchymal Transition; D006515:Hepatitis B virus / Q000378:metabolism* / Q000472:pathogenicity; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology*; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D000071250:Snail Family Transcription Factors; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*; D054334:Viral Regulatory and Accessory Proteins
chemical_list: D064413:3-Phosphoinositide-Dependent Protein Kinases; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D000071250:Snail Family Transcription Factors; D015534:Trans-Activators; D014157:Transcription Factors; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein