Hepatitis C virus core protein interacts with Snail and histone deacetylases to promote the metastasis of hepatocellular carcinoma

Oncogene. 2016 Jul 14;35(28):3626-35. doi: 10.1038/onc.2015.428. Epub 2015 Nov 9.

Abstract

Downregulation of E-cadherin by the transcriptional repressor Snail is associated with acquisition of metastatic potential. Although hepatitis C virus (HCV) core protein has been implicated in hepatocarcinogenesis, it is unclear whether Snail is involved in HCV core-induced dysregulation of E-cadherin. Herein, we investigated the mechanism by which HCV core induces E-cadherin repression and the role of Snail in HCV core-mediated invasiveness and metastasis. We found that HCV infection, especially HCV core expression, effectively induced the epithelial-mesenchymal transition (EMT) in hepatoma cells by repressing E-cadherin. HCV core interacted with Snail and enhanced its binding to the E-box in the promoter region of E-cadherin, leading to decreased E-cadherin promoter activity. We found that HCV core, Snail, and the histone deacetylases HDAC1/HDAC2 formed a co-repressor complex at the E-cadherin promoter. Moreover, HCV core was shown to stabilize Snail through activation of the PI3K/Akt/GSK3β pathway. Silencing Snail expression restored E-cadherin expression and inhibited HCV core-promoted tumor growth and distant lung metastasis in vivo. Collectively, these results demonstrated that HCV core induced EMT by interacting with the transcriptional repressor complex Snail/HDACs at the E-cadherin promoter, which led to E-cadherin repression and increased invasiveness of hepatoma cells. These findings increase understanding of factors regulating metastasis in hepatoma and may ultimately lead to the development of novel treatment strategies for HCV-associated hepatocellular carcinoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Cadherins / genetics
  • Cadherins / metabolism
  • Carcinoma, Hepatocellular / genetics
  • Carcinoma, Hepatocellular / metabolism*
  • Carcinoma, Hepatocellular / pathology
  • Cell Line, Tumor
  • Epithelial-Mesenchymal Transition / genetics
  • Hepacivirus / genetics
  • Hepacivirus / metabolism*
  • Histone Deacetylases / metabolism*
  • Humans
  • Liver Neoplasms / genetics
  • Liver Neoplasms / metabolism*
  • Liver Neoplasms / pathology
  • Mice, Nude
  • Microscopy, Fluorescence
  • Neoplasm Metastasis
  • Phosphatidylinositol 3-Kinases / metabolism
  • Promoter Regions, Genetic / genetics
  • Protein Binding
  • RNA Interference
  • Signal Transduction
  • Snail Family Transcription Factors / metabolism*
  • Transplantation, Heterologous
  • Tumor Burden
  • Viral Core Proteins / genetics
  • Viral Core Proteins / metabolism*

Substances

  • Cadherins
  • Snail Family Transcription Factors
  • Viral Core Proteins
  • Phosphatidylinositol 3-Kinases
  • Histone Deacetylases