title: A new diagnostic marker for secreted Epstein-Barr virus encoded LMP1 and BARF1 oncoproteins in the serum and saliva of patients with nasopharyngeal carcinoma.
abstract: OBJECTIVE
  EBV has been associated with nasopharyngeal carcinomas (NPC). In North Africa, the incidence is bimodal-the first peak occurring at approximately 20 years of age and the second peak occurring at approximately 50 years. Standard diagnostic tests based on immunofluorescence using anti-IgA EBV have shown that young North African patients have a negative serology compared with older patients. We are interested in two EBV-encoded oncoproteins, LMP1 and BARF1, which have thus far not been studied in terms of their potential as diagnostic markers for NPC. These two viral oncoproteins have been detected in cell culture media, so we tested whether they could be detected in the serum and saliva of patients with NPC.
  
  
  METHODS
  LMP1 and BARF1 proteins were analyzed in the sera and saliva of young patients and adult patients with NPC from North Africa and China. We then examined whether the secreted proteins had biological activity by analyzing their mitogenic activity.
  
  
  RESULTS
  Both LMP1 and BARF1 were present in the serum and saliva from North African and Chinese patients with NPC. All young North African patients secreted both proteins, whereas 62% and 100% of adult patients secreted LMP1 and BARF1, respectively. From animal studies, the secreted LMP1 was associated with exosome-like vesicles. These secreted EBV oncoproteins showed a powerful mitogenic activity in B cells.
  
  
  CONCLUSIONS
  Both proteins will be a good diagnostic marker for NPC whereas BARF1 is a particularly promising marker for all ages of patients with NPC. Their mitogenic activity suggests their implication in the oncogenic development of NPC.
authors.affiliation: Laboratoire de Virologie Moléculaire, UMR5537, Centre National de la Recherche Scientifique, Faculté de Médecine Laennec, Université Lyon-1, Lyon Cedex, France.
authors.forename: Karim
authors.initials: K
authors.lastname: Houali
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Wang
authors.forename: Yuko
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Djamel
authors.initials: D
authors.lastname: Djennaoui
authors.forename: John
authors.initials: J
authors.lastname: Nicholls
authors.forename: Sylvie
authors.initials: S
authors.lastname: Fiorini
authors.forename: Abdelmadjid
authors.initials: A
authors.lastname: Bouguermouh
authors.forename: Tadamasa
authors.initials: T
authors.lastname: Ooka
mesh_terms: D000328:Adult; D000818:Animals; D015703:Antigens, CD / Q000032:analysis; D045744:Cell Line, Tumor; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008213:Lymphocyte Activation; D051379:Mice; D008934:Mitogens / Q000494:pharmacology; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis* / Q000821:virology; D010980:Platelet Membrane Glycoproteins / Q000032:analysis; D012463:Saliva / Q000737:chemistry*; D060149:Tetraspanin 30; D014763:Viral Matrix Proteins / Q000032:analysis* / Q000097:blood / Q000494:pharmacology; D014764:Viral Proteins / Q000032:analysis* / Q000097:blood / Q000494:pharmacology