title: Consistent high concentration of the viral microRNA BART17 in plasma samples from nasopharyngeal carcinoma patients--evidence of non-exosomal transport.
abstract: BACKGROUND
  Because latent Epstein Barr (EBV)-infection is a specific characteristic of malignant nasopharyngeal carcinoma (NPC), various molecules of viral origin are obvious candidate biomarkers in this disease. In a previous study, we could show in a few clinical samples that it was possible to detect a category of EBV microRNAs called miR-BARTs in the plasma of at least a fraction of NPC patients. The first aim of the present study was to investigate the status of circulating miR-BART17-5p (one of the miR-BARTs hereafter called miR-BART17) and EBV DNA in a larger series of NPC plasma samples. The second aim was to determine whether or not circulating miR-BART17 was carried by plasma exosomes.
  
  
  METHODS
  Plasma samples were collected from 26 NPC patients and 10 control donors, including 9 patients with non-NPC Head and Neck squamous cell carcinoma and one healthy EBV carrier. Concentrations of miR-BART17 and two cellular microRNAs (hsa-miR-16 and -146a) were assessed by real-time quantitative PCR with spike-in normalization and absolute quantification. In addition, for 2 patients, exosome distributions of miR-BART17 and miR-16 were investigated following plasma lipoprotein fractionation by isopycnic density gradient ultrcentrifugation.
  
  
  RESULTS
  The miR-BART17 was significantly more abundant in plasma samples from NPC patients compared to non-NPC donors. Above a threshold of 506 copies/mL, detection of miR-BART17 was highly specific for NPC patients (ROC curve analysis: AUC=0.87 with true positive rate = 0.77, false positive rate = 0.10). In this relatively small series, the concentration of plasma miR-BART17 and the plasma EBV DNA load were not correlated. When plasma samples were fractionated, miR-BART17 co-purified with a protein-rich fraction but not with exosomes.
  
  
  CONCLUSIONS
  Detection of high concentrations of plasma miR-BART17 is consistent in NPC patients. This parameter is, at least in part, independent of the viral DNA load. Circulating miR-BART17 does not co-purify with exosomes.
authors.affiliation: CNRS-UMR 8126 and Institut de Cancérologie Gustave Roussy, Université Paris-Sud 11, 39 Rue Camille Desmoulins, Villejuif 94805, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Gourzones
authors.forename: François-Régis
authors.initials: FR
authors.lastname: Ferrand
authors.forename: Corinne
authors.initials: C
authors.lastname: Amiel
authors.forename: Benjamin
authors.initials: B
authors.lastname: Vérillaud
authors.forename: Ana
authors.initials: A
authors.lastname: Barat
authors.forename: Maryse
authors.initials: M
authors.lastname: Guérin
authors.forename: Charles-Henry
authors.initials: CH
authors.lastname: Gattolliat
authors.forename: Aurore
authors.initials: A
authors.lastname: Gelin
authors.forename: Jihène
authors.initials: J
authors.lastname: Klibi
authors.forename: Arij Ben
authors.initials: AB
authors.lastname: Chaaben
authors.forename: Véronique
authors.initials: V
authors.lastname: Schneider
authors.forename: Fethi
authors.initials: F
authors.lastname: Guemira
authors.forename: Joël
authors.initials: J
authors.lastname: Guigay
authors.forename: Philippe
authors.initials: P
authors.lastname: Lang
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Jimenez-Pailhes
authors.forename: Pierre
authors.initials: P
authors.lastname: Busson
mesh_terms: D000328:Adult; D000368:Aged; D001692:Biological Transport; D015415:Biomarkers / Q000097:blood*; D002277:Carcinoma; D004279:DNA, Viral / Q000097:blood; D055354:Exosomes / Q000821:virology; D005260:Female; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000097:blood* / Q000378:metabolism; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000473:pathology* / Q000821:virology*; D010949:Plasma / Q000737:chemistry*; D012367:RNA, Viral / Q000097:blood* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D015415:Biomarkers; D004279:DNA, Viral; D035683:MicroRNAs; D012367:RNA, Viral