Immunohistochemical evaluation of Ki-67 antigen, p27 kip1 and MCM3 proteins in odontogenic keratocysts

Odontogenic keratocysts are usually in need of extensive treatment and are concerned mostly by researches in order to find their biological behavior. M inichromosome maintenance3 (MCM3) over-expression has been reported in several human beings affected by odontogenic. To our knowledge there is no article about MCM3 expression in odontogenic keratocyst. The aim of this study was to evaluate MCM3 in odontogenic keratocysts and compare it to Ki-67 and p27.

Total of 23 OKC specimens were selected from Razi laboratory, they were reconfirmed by two indipendent pathologists. Clinicohistopathological data were recorded and standard streptavidin-biotin peroxidase method of immuohistochemical (IHC) staining was conducted for Ki-67 antigen, p27 Kip1 and MCM3. The immunostained cells were counted on 10 HPF (Labeling Index) and then classified to negative, low, moderate and high levels. Statistical analysis was done by SPSS 13 using Freidman & Spearman's Rho test s and PLUM - Ordinal Regression. P-value less than 0.05 were considered significant.

Ki-67 was stained mostly in the basal and suprabasal cells but p27 was found in the upper layers. No sample was stained by MCM3. There were significant differences among these proteins (MCM3 compared with Ki-67 & p27) not between p27 and Ki-67. No correlation was found among age, location and lesion size with these markers.

Most of the odontogenic keratocysts expressed low levels of both Ki-67 and p27. We also found MCM3 is not implicated in the pathogenesis of OKC.