Immuno-histochemical Expression of p53 Protein and iNOS in Odontogenic Cysts
Sopee Poomsawat DDS, MSc, PhD*, Jirapa Punyasingh DDS, MS*, Paisarn Vejchapipat MD, PhD*
Affiliation : * Department of Oral Pathology, Faculty of Dentistry, Mahidol University, Bangkok, Thailand ** Department of Surgery, Faculty of Medicine, Chulalongkorn University, Bangkok., Thailand
Objective : The present study investigated the expression of p53 protein and iNOS in odontogenic keratocysts
(OKCs), dentigerous cysts (DCs) and radicular cysts (RCs) and determined the correlation of these 2 proteins
within each cyst type.
Material and Method: p53 and iNOS in epithelial lining cells were analyzed in 20 OKCs, 20 DCs and 20 RCs
using immuno-histochemistry. The percentage of positive cells was assessed and presented as mean + SD.
The correlation between the expressions of these 2 proteins in each cyst was carried out using Spearman
correlation analysis.
Results : p53 was found in 95% of OKCs, 50% of DCs and 65% of RCs. p53-positive cells in OKCs (12.2 +
8.8%) were significantly higher than those in DCs (1.4 + 3.2%) and RCs (1.3 + 2.4%). iNOS was found in
all examined lesions. Statistically, iNOS-positive cells in RCs (86.9 + 9.9%) were lower than those in OKCs
(94.8 + 3.5%) and DCs (96.1 + 4.4%). No correlation between the expression of p53 and iNOS was found in
each cyst.
Conclusion : p53 was over expressed in OKCs compared with other lesions. RCs showed the lowest expression
of iNOS.
Keywords : Dentigerous cyst, Immuno-histochemistry, Nitric oxide synthase type II, Odontogenic cysts, Radicular cyst, Tumor suppressor protein p53
