Hepatitis B viral X protein interacts with tumor suppressor adenomatous polyposis coli to activate Wnt/β-catenin signaling.
HBV X protein is a transactivator of several cellular signaling pathways including Wnt which contributes to HBV associated neoplasia. The Wnt/β-catenin pathway is associated with HCC-initiating cells. Here we perform a functional screen for host factors involved in the transactivational properties of HBx. We identify adenomatous polyposis coli (APC) as a binding partner of HBx and further determine that HBx competitively binds APC to displace β-catenin from its degradation complex. This results in β-catenin upregulation in the nucleus and the activation of Wnt signaling. We show that Wnt inhibitors curcumin and quercetin target downstream β-catenin activity and effectively repress HBx-mediated regulation of c-MYC and E-cadherin. Our results provide a pathological mechanism of HBx induced malignant transformation.
The Department of Biological Sciences, Seoul National University, Republic of Korea.
Antony
A
Hsieh
Hyeon-Seop
HS
Kim
Seung-Oe
SO
Lim
Dae-Yeul
DY
Yu
Guhung
G
Jung
D025601:Adenomatous Polyposis Coli Protein / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000821:virology; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D008113:Liver Neoplasms / Q000378:metabolism / Q000821:virology; D013058:Mass Spectrometry; D051379:Mice; D008822:Mice, Transgenic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015534:Trans-Activators / Q000378:metabolism*; D015533:Transcriptional Activation; D054334:Viral Regulatory and Accessory Proteins; D051153:Wnt Proteins / Q000378:metabolism*; D051176:beta Catenin / Q000378:metabolism*
D025601:Adenomatous Polyposis Coli Protein; D015534:Trans-Activators; D054334:Viral Regulatory and Accessory Proteins; D051153:Wnt Proteins; D051176:beta Catenin; C057628:hepatitis B virus X protein