Related Experiment Video

Updated: Aug 14, 2026

Two Methods of Heterokaryon Formation to Discover HCV Restriction Factors
16:49

Two Methods of Heterokaryon Formation to Discover HCV Restriction Factors

Published on: July 16, 2012

Hepatitis C virus core protein inhibits tumor suppressor protein promyelocytic leukemia function in human hepatoma

Kerstin Herzer1, Sandra Weyer, Peter H Krammer

  • 1I. Medical Department, Johannes Gutenberg Universität, Mainz, Germany.

Cancer Research
|December 3, 2005
PubMed

Insights

Hepatitis C virus (HCV) core protein disrupts the tumor suppressor promyelocytic leukemia (PML) pathway. This interaction inhibits apoptosis and may drive hepatocellular carcinoma development by inactivating the PML-IV/p53 axis.

Area of Science:

  • Molecular Biology
  • Virology
  • Oncology

Background:

  • The tumor suppressor protein promyelocytic leukemia (PML) regulates apoptosis and antiviral responses, localizing to PML-nuclear bodies (PML-NBs) that modulate p53 activity.
  • Hepatitis C virus (HCV) infection is linked to hepatocellular carcinoma and often unresponsive to therapy, with underlying mechanisms for cancer development remaining unclear.
  • PML-nuclear bodies (PML-NBs) are targeted during viral infections, suggesting a role in antiviral defense and potential links to viral oncogenesis.

Purpose of the Study:

  • To investigate the interaction between Hepatitis C virus (HCV) core protein and the PML tumor suppressor pathway.
  • To elucidate the mechanism by which HCV core protein influences PML-IV and p53 activity.
  • To determine the role of this interaction in the context of HCV-associated hepatocellular carcinoma development.

Main Methods:

  • Immunofluorescence microscopy to observe the localization of HCV core protein and its colocalization with PML and p53 within PML-NBs.
  • Co-immunoprecipitation assays to confirm the interaction between HCV core protein and PML isoform IV (PML-IV).
  • Apoptosis assays and analysis of p53 target gene expression (e.g., CD95) in the presence and absence of HCV core protein and PML.

Main Results:

  • HCV core protein localizes to the nucleus and colocalizes with p53 within PML-NBs, interacting specifically with PML-IV.
  • HCV core protein inhibits PML-IV-induced apoptosis and impairs the coactivator function of PML-IV for proapoptotic p53 target genes.
  • HCV core expression abrogates p53 posttranslational modifications (phosphorylation and acetylation) crucial for its activation, independent of PML-NB formation levels.

Conclusions:

  • HCV core protein directly interferes with the tumor suppressor function of the PML-IV/p53 pathway.
  • Inhibition of PML-IV-mediated apoptosis and p53 activation by HCV core protein presents a potential mechanism for HCV-associated hepatocellular carcinoma.
  • Targeting the PML tumor suppressor pathway by HCV offers insights into viral oncogenesis and potential therapeutic strategies.

More Related Videos

Development of a Hepatitis B Virus Reporter System to Monitor the Early Stages of the Replication Cycle09:35

Development of a Hepatitis B Virus Reporter System to Monitor the Early Stages of the Replication Cycle

Published on: February 1, 2017

A Protocol for Analyzing Hepatitis C Virus Replication13:04

A Protocol for Analyzing Hepatitis C Virus Replication

Published on: June 26, 2014

Related Concept Videos

Inhibitors of Viral Protein Synthesis01:30

Inhibitors of Viral Protein Synthesis

Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's translational apparatus. In response, host cells deploy a critical innate immune defense involving interferons, specialized cytokines that play a central role in inhibiting viral propagation.Upon viral detection, infected cells release interferons that bind to receptors on adjacent uninfected cells, activating the JAK-STAT signaling pathway and...
Mechanisms of Retrovirus-induced Cancers01:51

Mechanisms of Retrovirus-induced Cancers

Retroviruses are RNA viruses that have been shown to cause cancers in diverse species, including chickens, mice, cats, and monkeys. The RNA genomes of these viruses are first reverse-transcribed into single and then double-stranded DNA (dsDNA) copies. This dsDNA called proviral DNA then integrates into the host genome. Subsequently, the host cell transcribes the proviral DNA in concert with the chromosomal DNA. This leads to the production of viral RNA and proteins that assemble at the host...
Mechanisms of Retrovirus-induced Cancers01:51

Mechanisms of Retrovirus-induced Cancers

Retroviruses are RNA viruses that have been shown to cause cancers in diverse species, including chickens, mice, cats, and monkeys. The RNA genomes of these viruses are first reverse-transcribed into single and then double-stranded DNA (dsDNA) copies. This dsDNA called proviral DNA then integrates into the host genome. Subsequently, the host cell transcribes the proviral DNA in concert with the chromosomal DNA. This leads to the production of viral RNA and proteins that assemble at the host...
Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
Inhibition of Cdk Activity02:34

Inhibition of Cdk Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
Inhibition of CDK Activity02:34

Inhibition of CDK Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...