The EBV oncogene LMP1 protects lymphoma cells from cell death through the collagen-mediated activation of DDR1

Blood. 2013 Dec 19;122(26):4237-45. doi: 10.1182/blood-2013-04-499004. Epub 2013 Oct 17.

Abstract

The malignant Hodgkin and Reed-Sternberg (HRS) cells of Hodgkin lymphoma are surrounded by a tumor microenvironment that is composed of a variety of cell types, as well as noncellular components such as collagen. Although HRS cells harbor oncogenic Epstein-Barr virus (EBV) in approximately 50% of cases, it is not known if the tumor microenvironment contributes to EBV-driven lymphomagenesis. We show that expression of the EBV-encoded latent membrane protein-1 (LMP1) in primary human germinal center B cells, the presumed progenitors of HRS cells, upregulates discoidin domain receptor 1 (DDR1), a receptor tyrosine kinase activated by collagen. We also show that HRS cells intimately associated with collagen frequently overexpress DDR1 and that short-term exposure to collagen is sufficient to activate DDR1 in Hodgkin lymphoma-derived cell lines. The ectopic expression of DDR1 significantly increased the survival of collagen-treated DG75 Burkitt lymphoma cells, following etoposide treatment. Conversely, knockdown of DDR1 significantly decreased the survival of collagen-treated L428 Hodgkin lymphoma cells in the absence of specific apoptotic stimulus, suggesting that DDR1 also influences baseline survival. Our results identify a hitherto unknown function for collagen in protecting Hodgkin lymphoma cells from apoptosis and suggest an important contribution of the tumor microenvironment in promoting the oncogenic effects of EBV.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • B-Lymphocytes / cytology*
  • B-Lymphocytes / physiology
  • Burkitt Lymphoma / genetics
  • Burkitt Lymphoma / pathology
  • Cell Death / physiology
  • Cells, Cultured
  • Collagen / metabolism
  • Discoidin Domain Receptor 1
  • Epstein-Barr Virus Infections / genetics*
  • Epstein-Barr Virus Infections / pathology
  • Gene Expression Regulation, Viral
  • Gene Knockdown Techniques
  • Germinal Center / cytology
  • Herpesvirus 4, Human / genetics*
  • Hodgkin Disease / genetics*
  • Hodgkin Disease / pathology
  • Humans
  • Phosphorylation / physiology
  • Receptor Protein-Tyrosine Kinases / genetics
  • Receptor Protein-Tyrosine Kinases / metabolism*
  • Reed-Sternberg Cells / cytology
  • Reed-Sternberg Cells / physiology
  • Tumor Microenvironment / physiology
  • Viral Matrix Proteins / genetics*

Substances

  • EBV-associated membrane antigen, Epstein-Barr virus
  • Viral Matrix Proteins
  • Collagen
  • DDR1 protein, human
  • Discoidin Domain Receptor 1
  • Receptor Protein-Tyrosine Kinases