title: Morphological and molecular features of oral fluid-derived exosomes: oral cancer patients versus healthy individuals.
abstract: OBJECTIVE
  Oral cancer (OC) patients are at high risk to develop recurrent disease or secondary primary cancers with no available biomarkers to detect these events until a visible lesion is readily present and diagnosed by biopsy. Exosomes secreted by cancer cells are involved in tumor growth, invasion and metastasis. We aimed to determine morphological and molecular differences between oral fluid (OF)-derived exosomes of OC patients and those isolated from healthy individuals (HI).
  
  
  METHODS
  OF from OC patients (n = 36) and HI (n = 25) was initially assessed by nanoparticle tracking analysis (NTA). Following ultracentrifugation, exosomal pellets of OC patients and HI were morphologically examined by transmission electron microscopy and atomic force microscopy (AFM). Enzyme-linked immunosorbent assay (ELISA) and western blotting (WB) were used to analyze the expression of exosomal markers--CD9, CD81 and CD63.
  
  
  RESULTS
  NTA showed that OC samples of OF had a significantly higher concentration of nanoparticles/ml (p = 0.01) and modal nanoparticle size (p = 0.002) compared to HI. The difference in size was structurally highlighted by AFM three-dimensional images applied on exosomal pellets. ELISA and WB showed differential expression of exosomal markers in OC exosomes compared to HI: lower expression of CD81 and CD9 in contrast to a higher expression of CD63 (~53 kDa).
  
  
  CONCLUSIONS
  OF-derived exosomes from OC patients differ both morphologically and molecularly from exosomes present in HI. This study is a baseline that provides a starting point for finding exosomal biomarkers for early detection of malignant changes in high-risk patients without overt clinical signs/lesions.
authors.affiliation: Department of Oral Pathology and Oral Medicine, School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Ayelet
authors.initials: A
authors.lastname: Zlotogorski-Hurvitz
authors.affiliation: Department of Oral Pathology and Oral Medicine, School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Dan
authors.initials: D
authors.lastname: Dayan
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dental Medicine, Tel Aviv University and Department of Oral and Maxillofacial Surgery, Rabin Medical Center, Petah Tikva, Israel.
authors.forename: Gavriel
authors.initials: G
authors.lastname: Chaushu
authors.affiliation: Departments of Diagnostics and Oral Medicine, Institute of Dentistry, University of Oulu and Oulu University Hospital, Oulu, Finland.|Medical Research Center, Oulu, Finland.|Institute of Dentistry, University of Helsinki, Helsinki, Finland.
authors.forename: Tuula
authors.initials: T
authors.lastname: Salo
authors.affiliation: Department of Oral Pathology and Oral Medicine, School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel. lmy@netvision.net.il.|Institute of Pathology, The Chaim Sheba Medical Center, Tel Hashomer, Israel. lmy@netvision.net.il.
authors.forename: Marilena
authors.initials: M
authors.lastname: Vered
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis*; D015153:Blotting, Western; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D055354:Exosomes / Q000737:chemistry* / Q000648:ultrastructure*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D009055:Mouth / Q000378:metabolism*; D009062:Mouth Neoplasms / Q000378:metabolism / Q000473:pathology*; D053758:Nanoparticles / Q000737:chemistry*; D014461:Ultracentrifugation
chemical_list: D015415:Biomarkers
keywords: Atomic force microscopy; Nanoparticle tracking analysis; Oral cancer; Oral fluid-derived exosomes; Tetraspanins