Evaluation of Ki-67 and cyclin D1 expression in odontogenic keratocysts and orthokeratinised jaw cysts.
BACKGROUND
Orthokeratinised jaw cyst (OJC) is an entity distinct from odontogenic keratocyst (OKC) that has not been fully characterised at the molecular level.


OBJECTIVE
To compare the proliferative activity of the epithelial linings of OKC and OJC immunohistochemically, using Ki-67 and cyclin D1 as markers of cellular proliferation and activity.


METHODS
The total numbers of positively stained cells per 10 consecutive lengths of a light microscope calibration ruler were counted in each case (OKC, n = 15; OJC, n = 15) and the composite data were statistically compared.


CONCLUSIONS
OJC showed significantly fewer Ki-67 and cyclin D1 positive cells than OKC, a finding consistent with the clinically more indolent behaviour of the OJC. Ki-67 expression was mainly detected in the suprabasal cell layers in OKC. Expression of Ki-67 was more uniform in OJC and notably without a significant predilection for the supra-basal compartment. The accumulation of Ki-67 positive cells supra-basally in OKC raises the possibility that a process of asymmetrical cell division may be operational in OKC. Expression of Ki-67 and cyclin D1 differed significantly quantitatively and by distribution pattern in OKC and OJC respectively thereby suggesting that the presence of cyclin D1 protein in OKC and OJC may not necessarily reflect production of this molecule by cycling cells.
Division of Oral Pathology, Faculty of Health Sciences, University of the Witwatersrand, South Africa.
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Gani
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Mahomed
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Meer
D002452:Cell Count; D002455:Cell Division; D002467:Cell Nucleus / Q000473:pathology; D049109:Cell Proliferation; D004396:Coloring Agents; D019938:Cyclin D1 / Q000032:analysis*; D004801:Eosine Yellowish-(YS); D004847:Epithelial Cells / Q000473:pathology; D004848:Epithelium / Q000473:pathology; D005456:Fluorescent Dyes; D006416:Hematoxylin; D006801:Humans; D007570:Jaw Cysts / Q000473:pathology*; D007633:Keratins / Q000032:analysis; D019394:Ki-67 Antigen / Q000032:analysis*; D009807:Odontogenic Cysts / Q000473:pathology*
C530104:CCND1 protein, human; D004396:Coloring Agents; D005456:Fluorescent Dyes; D019394:Ki-67 Antigen; D019938:Cyclin D1; D007633:Keratins; D004801:Eosine Yellowish-(YS); D006416:Hematoxylin