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

FZ Cader, M Vockerodt, S Bose, E Nagy… - Blood, The Journal …, 2013 - ashpublications.org
FZ Cader, M Vockerodt, S Bose, E Nagy, MA Brundler, P Kearns, PG Murray
Blood, The Journal of the American Society of Hematology, 2013ashpublications.org
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 …
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.
ashpublications.org