title: Claudin expression and tight junction protein localization in the lining epithelium of the keratocystic odontogenic tumors, dentigerous cysts, and radicular cysts.
abstract: OBJECTIVE
  The aim of this study was to evaluate the expression and localization of tight junction proteins (TJPs) or claudins in the keratocystic odontogenic tumor (KCOT) and to correlate with its biological behavior.
  
  
  METHODS
  Five claudins (-1, -3, -4, -5, and 7) were examined immunohistochemically in 25 KCOTs and compared with 10 dentigerous cysts (DCs) and 10 radicular cysts (RCs).
  
  
  RESULTS
  Marked claudin-3 loss of expression in KCOT basal layer (n=24/25; 96%) compared with DCs (n=1/10; 10%) and RCs (n=5/10; 50%) (P<.05) suggests that claudin-3 downregulation may indicate altered or loss of basal cell polarity and impaired barrier function of KCOT lining epithelium and this might contribute indirectly to its biological behavior. In contrast, claudins-1, -4, -5, and -7 distribution patterns were less distinctive in all three entities, suggesting that these TJP molecules probably play limited roles in influencing their different growth potentials.
  
  
  CONCLUSIONS
  Present findings suggest that differential claudin expressions in the lining epithelium of KCOTs, DCs, and RCs probably reflect their neoplastic or nonneoplastic nature.
authors.affiliation: Department of Oral Pathology, Oral Medicine and Periodontology, Faculty of Dentistry, University of Malaya, 50603 Kuala Lumpur, Malaysia. chsiar@gmail.com
authors.forename: Chong Huat
authors.initials: CH
authors.lastname: Siar
authors.forename: Syed Amjad
authors.initials: SA
authors.lastname: Abbas
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002467:Cell Nucleus / Q000473:pathology; D016764:Cell Polarity; D002648:Child; D062445:Claudin-1 / Q000032:analysis; D062465:Claudin-3 / Q000032:analysis; D062506:Claudin-4 / Q000032:analysis; D062507:Claudin-5 / Q000032:analysis; D057167:Claudins / Q000032:analysis*; D003593:Cytoplasm / Q000473:pathology; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D003803:Dentigerous Cyst / Q000473:pathology*; D015536:Down-Regulation; D004847:Epithelial Cells / Q000473:pathology; D004848:Epithelium / Q000473:pathology; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009808:Odontogenic Tumors / Q000473:pathology*; D011842:Radicular Cyst / Q000473:pathology*; D062725:Tight Junction Proteins / Q000032:analysis*; D055815:Young Adult
chemical_list: C568108:CLDN1 protein, human; C568122:CLDN3 protein, human; C568157:CLDN4 protein, human; C107466:CLDN5 protein, human; C473255:CLDN7 protein, human; D062445:Claudin-1; D062465:Claudin-3; D062506:Claudin-4; D062507:Claudin-5; D057167:Claudins; D062725:Tight Junction Proteins