Title

Kaposi's Sarcoma-Associated Herpesvirus G-protein Coupled Receptor Activates the Canonical Wnt/β-catenin Signaling Pathway.

Funding Source

National Institutes of Health

Grant Number

P20GM103424, R01HD51998, R21HD076283

Department

Department of Biology

Document Type

Article

Publication Date

12-17-2014

Abstract

Abstract Background: KSHV is a tumorigenic γ-herpesvirus that has been identified as the etiologic agent of Kaposi's sarcoma (KS), a multifocal highly vascularized neoplasm that is the most common malignancy associated with acquired immunodeficiency syndrome (AIDS). The virus encodes a constitutively active chemokine receptor homologue, vGPCR that possesses potent angiogenic and tumorigenic properties, and is critical for KSHV pathobiology. To date, a number of signaling pathways have been identified as key in mediating vGPCR oncogenic potential. Findings: In this study, we identify a novel pathway, the Wnt/β-catenin pathway, which is dysregulated by vGPCR expression in endothelial cells. Expression of vGPCR in endothelial cells enhances the nuclear accumulation of β-catenin, that correlates with an increase in β-catenin transcriptional activity. Activation of β-catenin signaling by vGPCR is dependent on the PI3K/Akt pathway, as treatment of vGPCR-expressing cells with a pharmacological inhibitor of PI3K, leads to a decreased activation of a β-catenin-driven reporter, a significant decrease in expression of β-catenin target genes, and reduced endothelial tube formation. Conclusions: Given the critical role of Wnt/β-catenin signaling in angiogenesis and tumorigenesis, the findings from this study suggest a novel mechanism in KSHV-induced malignancies.

Comments

DOI: 10.1186/s12985-014-0218-8

PubMed ID: 25514828

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