sphingosine-1-phosphate and Nasopharyngeal-Neoplasms

Undifferentiated nasopharyngeal carcinoma (NPC) is a cancer with high metastatic potential that is consistently associated with Epstein-Barr virus (EBV) infection. In this study, we have investigated the functional contribution of sphingosine-1-phosphate (S1P) signalling to the pathogenesis of NPC. We show that EBV infection or ectopic expression of the EBV-encoded latent genes (EBNA1, LMP1, and LMP2A) can up-regulate sphingosine kinase 1 (SPHK1), the key enzyme that produces S1P, in NPC cell lines. Exogenous addition of S1P promotes the migration of NPC cells through the activation of AKT; shRNA knockdown of SPHK1 resulted in a reduction in the levels of activated AKT and inhibition of cell migration. We also show that S1P receptor 3 (S1PR3) mRNA is overexpressed in EBV-positive NPC patient-derived xenografts and a subset of primary NPC tissues, and that knockdown of S1PR3 suppressed the activation of AKT and the S1P-induced migration of NPC cells. Taken together, our data point to a central role for EBV in mediating the oncogenic effects of S1P in NPC and identify S1P signalling as a potential therapeutic target in this disease. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Topics: Adult; Aged; Animals; Carcinoma; Cell Line, Tumor; Cell Movement; Epstein-Barr Virus Infections; Female; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Heterografts; Humans; Lysophospholipids; Male; Middle Aged; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; Oncogene Protein v-akt; Receptors, Lysosphingolipid; RNA, Messenger; Signal Transduction; Sphingosine; Sphingosine-1-Phosphate Receptors; Up-Regulation