Expression of Bcl-2 and epithelial growth factor receptor proteins in keratocystic odontogenic tumor in comparison with dentigerous cyst and ameloblastoma.
BACKGROUND
Keratocystic odontogenic tumor (KCOT) is a developmental odontogenic cyst on which various investigations have been focused due to its biological activities, high tendency to recur and different growth mechanisms in comparison with other cystic lesions. Previous studies have shown different biological and proliferative activities for the lining epithelium of KCOT. The aim of this study was immunohistochemical evaluation of Bcl-2 and epidermal growth factor receptor (EGFR) expression in KCOT compared with dentigerous cyst and ameloblastoma.


METHODS
Formalin-fixed and paraffin-embedded tissue sections of 16 cases of KCOT, 16 cases of dentigerous cyst and 16 cases of ameloblastoma were immunohistochemically analyzed to determine Bcl-2 and EGFR proteins' expression. Biotin-Stereotavidin method was used. It was observed by two oral pathologists separately, and the data were analyzed by Mann-Whitney and Kruskul-Wallis. P < 0.05 was considered as significant.


RESULTS
Regardless of staining intensity, all cases of ameloblastoma and KCOT except dentigerous cases were positively stained for Bcl-2. Expression of Bcl-2 was higher in the peripheral layer of ameloblastoma and basal layer of KCOT. Furthermore, all cases of ameloblastoma and dentigerous cysts except KCOT samples were positively stained for EGFR. Expression of EGFR was higher in the peripheral layer of ameloblastoma and basal layer of dentigerous cysts.


CONCLUSIONS
According to the expression of - Bcl-2 in ameloblastoma and KCOT, and no expression of EGFR in KCOT, it can be concluded that the biological activity and growth mechanisms of KCOT are different compared with other cystic lesions. However, the aggressive potential of KCOT is not as severe as that of a neoplasm such as ameloblastoma.
Dental implant Research Center and Department of Oral Pathology, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
Seyed Mohammad
SM
Razavi
Dental Materials Research Center and Department of Oral Pathology, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
Nakisa
N
Torabinia
General Pathologist, Isfahan, Iran.
Mohammad Reza
MR
Mohajeri
Postgraduate student, Department of Operative Dentistry, Azad University of Khorosgan, Isfahan, Iran.
Shahriyar
S
Shahriyary
General Dentist, Isfahan, Iran.
Shirin
S
Ghalegolab
General Dentist, Isfahan, Iran.
Samin
S
Nouri
Ameloblastoma; Bcl-2 protein; dentigerous cyst; epiderm; epidermal growth factor receptor; growth factor; immunohistochemistry; odontogenic tumor