햄스터 협낭암 발암과정에서 COX-2 발현

Abstract

Cyclooxygenase-2 (COX-2) is an inducible enzyme that is not found in normal conditions, but is induced by a variety of pathophysiologic conditions of tissues by growth factors, inflammatory stimuli, oncogenes and tumor promoters. COX-2 is upregulated in a number of epithelial cancers, including in oral premalignant and malignant lesions. The mode of action of COX-2 in carcinogenesis may include mutiple mechanisms that may be acting at different stages of malignant disease. In this study, the expression of COX-2 protein was assessed quantitatively and qualitatively by immunohistochemistry during DMBA-induced hamster buccal pouch carcinogenesis. The immunoreactivity for COX-2 protein increased as the tissue passed from hyperplasia to dysplasia and SCC. The highest mean expression was SCC at 14 week. The differences between COX-2 expression in the normal and that the dysplastic and carcinomatous lesions was statistically significant. In addition, the mean values of COX-2 expression in the stomal cells increased gradually during malignant progression. The results suggest that increased COX-2 expression may be associated with the chemically induced carcinogenic progression of hamster buccal pouch model. The gradual increasing COX-2 expression detected during the progressive manner toward more malignant lesions shows that the COX-2 protein can have an important role in both the early and the later stages of multistep oral carcinogenesis.