Epstein-barr virus induction of the hedgehog signalling pathway imposes a stem cell-like phenotype on human epithelial cells – implications for the pathogenesis of nasopharyngeal carcinoma

[摘要] Nasopharyngeal carcinoma (NPC) is endemic in Southern China and South East Asia, causally linked to Epstein-Barr virus (EBV) infection, and frequently shows dysregulation in a number of stem cell maintenance signalling pathways. This thesis has endeavoured to investigate the status of one of these pathways; the Hedgehog (HH) signalling pathway, in NPC tumours, and reveals the novel finding that EBV is able to active the HH signalling pathway through autocrine induction of the SHH ligand in the C666.1 authentic EBV-positive NPC-derived cell line and latently infected epithelial carcinoma cell lines. This study demonstrates that constitutive engagement of the HH pathway in EBV-infected epithelial cells in vitro induces the expression of a number of stemness-associated genes and imposes stem-like characteristics. Using epithelial cells expressing individual EBV latent genes, this study also investigates the viral protein responsible for HH dysregulation demonstrating that EBNA1, LMP1 and LMP2A are all capable of inducing SHH ligand and activating the HH pathway, but only LMP1 and LMP2A are able to induce expression of stemness-associated marker genes. These findings not only identify a role for dysregulated HH signalling in NPC oncogenesis but also provide a novel rationale for therapeutic intervention.

[发布机构] University:University of Birmingham;Department:Institute of Cancer Studies

[关键词] R Medicine;RC Internal medicine;RC0254 Neoplasms. Tumors. Oncology (including Cancer)