title: The roles of hepatitis B virus-encoded X protein in virus replication and the pathogenesis of chronic liver disease.
abstract: BACKGROUND
  Hepatitis B virus (HBV) is a major cause of chronic liver disease (CLD) and hepatocellular carcinoma (HCC) worldwide. More than 350 million people are at risk for HCC, and with few treatment options available, therapeutic approaches to targets other than the virus polymerase will be needed. This review suggests that the HBV-encoded X protein, HBx, would be an outstanding target because it contributes to the biology and pathogenesis of HBV in three fundamental ways.
  
  
  METHODS
  First, HBx is a trans-activating protein that stimulates virus gene expression and replication, thereby promoting the development and persistence of the carrier state. Second, HBx partially blocks the development of immune responses that would otherwise clear the virus, and protects infected hepatocytes from immune-mediated destruction. Thus, HBx contributes to the development of CLD without virus clearance. Third, HBx alters patterns of host gene expression that make possible the emergence of HCC. The selected literature cited is from the National Library of Medicine (Pubmed and Medline).
  
  
  CONCLUSIONS
  Understanding the mechanisms, whereby HBx supports virus replication and promotes pathogenesis, suggests that HBx will be an important therapeutic target against both virus replication and CLD aimed at the chemoprevention of HCC.
authors.affiliation: Temple University, College of Science and Technology, Department of Biology , Room 409 BioLife Science Building, 1900 N. 12th Street, Philadelphia, PA 19122 , USA +1 215 204 8434 ; +1 215 204 8359 ; feitelso@temple.edu.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Feitelson
authors.forename: Barbara
authors.initials: B
authors.lastname: Bonamassa
authors.forename: Alla
authors.initials: A
authors.lastname: Arzumanyan
mesh_terms: D000818:Animals; D015870:Gene Expression; D006515:Hepatitis B virus / Q000502:physiology*; D006801:Humans; D008107:Liver Diseases / Q000276:immunology / Q000378:metabolism*; D015534:Trans-Activators / Q000502:physiology*; D054334:Viral Regulatory and Accessory Proteins; D014779:Virus Replication
chemical_list: D015534:Trans-Activators; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein