Expression of cyclo-oxygenase-2 in human tongue carcinoma and its precursor lesions

The expression of Cox-2 protein was studied by immunohistochemistry in normal oral mucosa and in mucosa with various lesions of oral leukoplakia, including hyperplasia and dysplasia of squamous epithelium and frank invasive squamous carcinoma. A gradient of Cox-2 staining was found: the expression of Cox-2 was lowest in normal epithelium, somewhat increased in hyperplastic epithelium, further increased in dysplastic epithelium, and highest in invasive squamous cell carcinomas. The presence of Cox-2 in squamous cell carcinomas of the oral mucosa and its precursor lesions indicate that Cox-2 could participate in the carcinogenic process of these oral malignancies.