title: Potential relevance of cyclooxygenase-2 expression in keratocystic odontogenic tumours - an immunohistochemical study.
abstract: There is increasing evidence that overexpression of cyclooxygenase-2 (COX-2) plays an important role in tumour growth and spread of tumours by interfering with cell proliferation, cellular adhesion, immune surveillance, apoptosis, and angiogenesis. COX-2 levels are increased in various tumours. In this study, the expression of COX-2 in 116 specimens of keratocystic odontogenic tumours (KCOT) has been analyzed. KCOT is a benign neoplasm of odontogenic origin with an occasionally aggressive behavior leading to high recurrence rates. Formalin-fixed, paraffin-embedded blocks were sectioned and used for hematoxylin-eosin (H&E) staining and incubated with an anti-COX-2 monoclonal antibody for immunohistochemical examination. Detection of the COX-2 antibody was performed with the EnVision kit. Cellular staining pattern for COX-2 was cytoplasmatic, and the staining intensities were semi-quantitatively evaluated as follows: negative (-), mild (±) or strong (+). Mild to strong expression of COX-2 was observed in 83 (71.6%) cases; 34 (29.3%) of which were mild positive and 49 (42.2%) were strong positive. COX-2 stain was detected mainly in the epithelial lining. The expression of COX-2 in KCOT and the current knowledge of the role played by COX-2 in tumorigenesis further strengthen the current concept that the KCOT should be regarded as a neoplasm. Furthermore, the multitude of markers known to be overexpressed in KCOTs is suggestive of what could be called a 'network addiction' pattern, rather than a pathological mechanism dependant on a specific activated/suppressed gene, thus explaining its aggressive behavior.
authors.affiliation: Oral Medicine and Oncology, Portuguese Catholic University, Viseu, Portugal.
authors.forename: Rui Amaral
authors.initials: RA
authors.lastname: Mendes
authors.forename: João F C
authors.initials: JF
authors.lastname: Carvalho
authors.forename: Isaac
authors.initials: I
authors.lastname: van der Waal
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D002648:Child; D051546:Cyclooxygenase 2 / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D006801:Humans; D007633:Keratins; D008297:Male; D008339:Mandibular Neoplasms / Q000201:enzymology*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009808:Odontogenic Tumors / Q000201:enzymology*; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D055815:Young Adult
chemical_list: D007633:Keratins; D051546:Cyclooxygenase 2