Focal adhesion kinase (FAK) mediates the induction of pro-oncogenic and fibrogenic phenotypes in hepatitis C virus (HCV)-infected cells

PLoS One. 2012;7(8):e44147. doi: 10.1371/journal.pone.0044147. Epub 2012 Aug 28.

Abstract

Hepatitis C Virus (HCV) infection is one of the most common etiological factors involved in fibrosis development and its progression to hepatocellular carcinoma (HCC). The pivotal role of hepatic stellate cells (HCSs) and extracellular matrix (ECM) in fibrogenesis is now certainly accepted, while the network of molecular interactions connecting HCV is emerging as a master regulator of several biological processes including proliferation, inflammation, cytoskeleton and ECM remodeling. In this study, the effects of HCV proteins expression on liver cancer cells, both pro-invasive and pro-fibrogenic phenotypes were explored. As a model of HCV infection, we used permissive Huh7.5.1 hepatoma cells infected with JFH1-derived ccHCV. Conditioned medium from these cells was used to stimulate LX-2 cells, a line of HSCs. We found that the HCV infection of Huh7.5.1 cells decreased adhesion, increased migration and caused the delocalization of alpha-actinin from plasma membrane to cytoplasm and increased expression levels of paxillin. The treatment of LX-2 cells, with conditioned medium from HCV-infected Huh7.5.1 cells, caused an increase in cell proliferation, expression of alpha-smooth muscle actin, hyaluronic acid release and apoptosis rate measured as cleaved poly ADP-ribose polymerase (PARP). These effects were accompanied in Huh7.5.1 cells by an HCV-dependent increasing of FAK activation that physically interacts with phosphorylated paxillin and alpha-actinin, and a rising of tumor necrosis factor alpha production/release. Silencing of FAK by siRNA reverted all effects of HCV infection, both those directed on Huh7.5.1 cells, and those indirect effects on the LX-2 cells. Moreover and interestingly, FAK inhibition enhances apoptosis in HCV-conditioned LX-2 cells. In conclusion, our findings demonstrate that HCV, through FAK activation, may promote cytoskeletal reorganization and a pro-oncogenic phenotype in hepatocyte-like cells, and a fibrogenic phenotype in HSCs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actinin / genetics
  • Actinin / metabolism
  • Carcinoma, Hepatocellular / genetics
  • Carcinoma, Hepatocellular / metabolism*
  • Carcinoma, Hepatocellular / virology
  • Cell Adhesion
  • Cell Line, Tumor
  • Cell Movement
  • Cell Proliferation
  • Focal Adhesion Protein-Tyrosine Kinases / genetics
  • Focal Adhesion Protein-Tyrosine Kinases / metabolism*
  • Hepacivirus*
  • Hepatic Stellate Cells / metabolism*
  • Hepatic Stellate Cells / pathology
  • Hepatic Stellate Cells / virology
  • Hepatitis C / genetics
  • Hepatitis C / metabolism*
  • Humans
  • Liver / metabolism
  • Liver / pathology
  • Liver / virology
  • Liver Cirrhosis / metabolism
  • Liver Cirrhosis / pathology
  • Liver Cirrhosis / virology
  • Liver Neoplasms / genetics
  • Liver Neoplasms / metabolism*
  • Liver Neoplasms / virology
  • Paxillin / genetics
  • Paxillin / metabolism
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Paxillin
  • Tumor Necrosis Factor-alpha
  • Actinin
  • Focal Adhesion Protein-Tyrosine Kinases

Grants and funding

This study was supported by A. Cesalpino Foundation, and Associazione Italiana Per La Ricerca Sul Cancro (AIRC) Grant. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.