Investigation of Cyclooxygenase-2 Expression in Tissue: Protein and mRNA Levels Compared Between Patients with Oral Squamous Cell Carcinoma and Oral Lichen Planus

Aim: Cyclooxygenase-2 (COX-2) is a crucial enzyme in the prostaglandin cascade. Overexpression of the COX-2 enzyme has been associated with the pathogenesis and progression of certain cancers, including oral cancer. This study aimed to investigate the quantitative expression and immunohistochemistry (IHC) expression of COX-2 in tissue samples from patients with oral squamous cell carcinoma (OSCC) and oral lichen planus (OLP) to gain insight into its potential role in the pathogenesis of these oral diseases. Methods: A total of 76 samples were analyzed, consisting of 25 cases of OSCC, 27 cases of OLP, and 24 cases of normal oral mucosa. COX-2 expression was analyzed using IHC staining and quantitative polymerase chain reaction (qPCR). Statistical analysis was performed using the Chi-squared, Spearman’s, and Fisher’s exact tests, with significance declared at a P value of <.05. Results: The mRNA expression of COX-2 in OSCC tissues (3.17 ± 1.02) was found to be significantly higher than in OLP (1.65 ± 0.72) and normal (1.08 ± 0.79; P < .01). In addition, protein expression of COX-2 was significantly higher in cancer tissues than in normal and OLP ( P < .05). The oral cavity was the most common tumor site in the studied cases, representing 56% of OSCC cases, as determined by qPCR analysis ( P < .05). Conclusion: Understanding the involvement of COX-2 in these oral diseases has implications for the development of targeted therapies and personalized treatment approaches. Also, the identification of COX-2 as a potential biomarker may contribute to improved diagnostic accuracy and prognosis in patients with OSCC and OLP. Moreover, the qPCR method could be as effective a technique as IHC to evaluate COX-2 amplification.