Differential signaling pathways are activated in the Epstein-Barr virus-associated malignancies nasopharyngeal carcinoma and Hodgkin lymphoma

Cancer Res. 2004 Aug 1;64(15):5251-60. doi: 10.1158/0008-5472.CAN-04-0538.

Abstract

EBV is associated with the epithelial cancer, nasopharyngeal carcinoma (NPC), and the lymphoid malignancy, Hodgkin lymphoma (HL). The EBV latent membrane proteins 1 and 2A are expressed in these tumors. These proteins activate the phosphatidylinositol 3'-OH kinase (PI3K)/Akt pathway, which is commonly activated inappropriately in malignancy. In this study, the status of Akt activation and its targets, glycogen synthase kinase-3beta (GSK-3beta) and beta-catenin, was investigated in NPC and HL clinical specimens. In the majority of HL and NPC specimens, Akt was activated, indicating an important role for this kinase in the development and/or progression of these tumors. Akt phosphorylates and inactivates GSK-3beta, a negative regulator of the proto-oncoprotein beta-catenin that is aberrantly activated in many cancers. GSK-3beta was phosphorylated and inactivated with concomitant nuclear beta-catenin accumulation in the majority of NPC specimens. The malignant cells of the majority of HL cases, however, did not have inactivated GSK-3beta and lacked nuclear beta-catenin expression. These data indicate that this signaling arm of PI3K/Akt is universal and important in NPC pathogenesis but is apparently not affected in HL. These findings point to a divergence in pathways activated by EBV in different cellular contexts.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cytoskeletal Proteins / metabolism
  • Epstein-Barr Virus Infections / metabolism*
  • Epstein-Barr Virus Infections / virology
  • Glycogen Synthase Kinase 3 / antagonists & inhibitors
  • Glycogen Synthase Kinase 3 / metabolism
  • Glycogen Synthase Kinase 3 beta
  • Herpesvirus 4, Human / pathogenicity*
  • Hodgkin Disease / metabolism*
  • Hodgkin Disease / pathology
  • Hodgkin Disease / virology
  • Humans
  • Mice
  • Nasopharyngeal Neoplasms / metabolism*
  • Nasopharyngeal Neoplasms / pathology
  • Nasopharyngeal Neoplasms / virology
  • Phosphorylation
  • Protein Serine-Threonine Kinases / metabolism
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-akt
  • Signal Transduction*
  • Trans-Activators / metabolism
  • Transplantation, Heterologous
  • Tumor Cells, Cultured
  • Viral Matrix Proteins / genetics
  • Viral Matrix Proteins / physiology
  • beta Catenin

Substances

  • CTNNB1 protein, human
  • CTNNB1 protein, mouse
  • Cytoskeletal Proteins
  • EBV-associated membrane antigen, Epstein-Barr virus
  • Proto-Oncogene Proteins
  • Trans-Activators
  • Viral Matrix Proteins
  • beta Catenin
  • AKT1 protein, human
  • GSK3B protein, human
  • Glycogen Synthase Kinase 3 beta
  • Gsk3b protein, mouse
  • Protein Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt
  • Glycogen Synthase Kinase 3