Immunohistochemical expression of Cyclooxygenase 2 reflects the proliferative activity in the epithelium of odontogenic lesions

Vani Verma,Chetana Chandrashekar,Raghu Radhakrishnan,Monica Charlotte Solomon

doi:10.5195/d3000.2022.205

Abstract

Purpose: Odontogenic cysts and tumors comprise a major component of lesions of the oral and maxillofacial region. The pathogenesis of these lesions involves the interaction between the odontogenic epithelium and the ectomesenchyme. However, the clinical behavior of these biological entities is unpredictable. The aim of this study was to evaluate the role of Cyclooxygenase 2 (COX-2) in the pathogenesis and prognostication of odontogenic lesions.Material and method: : In this study formalin-fixed paraffin-embedded tissue section of Odontogenic Keratocyst (n=10) Dentigerous cyst (n=10), Radicular cyst (n=10) and unicystic ameloblastoma (n=10) were immunohistochemically stained with COX-2 (NCL2-COX-2- 4H12) and with Ki 67 (Ki-67 GM001) using standard staining protocols. The cytoplasmic expression of COX-2 in all the lesions was semi-quantitatively assessed. The pattern of expression of COX-2 among the different odontogenic lesions was statistical analyzed using the ANOVA test and the chi-square test.Results: All the 40 odontogenic lesions that were evaluated expressed COX-2 immunohistochemically. A high number of odontogenic epithelial cells expressed COX-2 in most of the odontogenic keratocyst, radicular cyst and unicystic ameloblastomas. The expression of COX-2 was significantly (p=0.036) higher in Unicystic Ameloblastomas and Radicular cyst compared to that of Odontogenic Keratocyst and the dentigerous cyst.Conclusion: The recognition that expression of COX-2 by odontogenic epithelial cells may indeed shed a new light on the biological mechanisms involved in the development of these benign yet aggressive lesions of the jaws. An insight into the molecular interactions occurring in the odontogenic epithelium will aid in better management of these lesions.

Highlights

Odontogenic lesions are the most common benign lesions that occur within the jaw bones
The recognition that expression of Cyclooxygenase 2 (COX-2) by odontogenic epithelial cells may shed a new light on the biological mechanisms involved in the development of these benign yet aggressive lesions of the jaws
In this study the expression of cyclooxygenase-2 was evaluated in 40 cases of odontogenic cysts and tumors that included 10 cases of dentigerous cysts, 10 cases of Radicular cyst, 10 cases of odontogenic keratocyst and 10 cases of Unicystic Ameloblastoma

Summary

Introduction

Odontogenic lesions are the most common benign lesions that occur within the jaw bones. These lesions are derived from the epithelium associated with the formation of the hard and soft tissues of the tooth. The Radicular cyst called the periapical cyst is the most common odontogenic cystic lesion. The World Health Organization classification of head and neck tumors describes Radicular cyst as a cyst of inflammatory origin associated with non-vital teeth [2]. Radicular cysts present as a swelling of the jaw and may be associated with pain/loosening of tooth, root resorption of the affected tooth and displacement of the adjacent teeth [3]

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