Potential relevance of cyclooxygenase-2 expression in keratocystic odontogenic tumours - an immunohistochemical study

Rui Amaral Mendes*, João F.C. Carvalho, Isaac Van Der Waal

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)


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.
Original languageEnglish
Pages (from-to)497-503
Number of pages7
JournalJournal of Oral Pathology and Medicine
Issue number6
Publication statusPublished - Jul 2011


  • COX-2
  • Keratocyst
  • Odontogenic neoplasm
  • Tumor


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