EXPRESSION OF METIOLLOPROTEINASES ( MMP2-MMP9 ) AND CYCLOOXIGENASES ( COX1-COX2 ) IN SALIVARY GLAND TUMORS

Background Salivary neoplasms of the major salivary glands are uncommon: the annual incidence rates in the world vary between greater than 0.05 and less than 2 per 100,000. Most salivary gland tumours are benign and they represent an histological heterogeneous group with the greatest diversity of morphological and cellular features, in fact, these tumours are characterized by an extremely varied histomorphological phenotype due to combinations of different epitheliomorphic and mesenchymomorphic features. The histogenesis is uncertain but the bicellular theory of origin has been accepted and states that malignant transformation of reserve cell from either the intercalated or excretory duct are responsible for the development of malignant salivary glands. The most common benign tumour is pleomorphic adenoma while the most common malignant tumour is the cystic adenoid carcinomas, a slow-growing tumour with a tendency for peri-neural invasion and haematogenous metastasis The role of some enzymes in carcinogenesis has been recognized, in particular matrix metalloproteinases enzymes and cyclooxygenases are involved in different steps of progression of carcinoma in the process of carcinogenesis. Our group is studying the expression of metalloproteinases (MMP-2, MMP-9) and cyclooxygenases (COX-1, COX-2) in tumours of salivary gland through immunohistochemistry and RT-PCR to identify eventual progression from benign phenotype towards malignant phenotype. Materials and Methods. In this paper we investigate fourteen (14) samples of salivary gland tumours. We highlighted the localization of MMP-2, MMP-9 and COX-1, COX-2 through immunohistochemistry and gene expression through RT-PCR analysis. Results. We detected the presence of MMP-2 and MMP-9 and COX-1, COX-2 in all samples examined, in particular in the ductal epithelium. Conclusions. Actually, we did not found a different expression of two classes of enzymes in tumours of salivary glands examined with reference to different phenotype. We shall continue our work because we believe that with a major numbers of cases it is possible to identify a linear progression from benign to malignant phenotype.