Background and Objectives: Squamous cell carcinomas (SCCs) of the head and neck are known for their aggresive growth and propensity to metastasize, which often results in poor prognosis. Tumor cell interaction with the basement membrane has historically been viewed as the crucial step in tumor invasion and future metastasis. The invasive and metastatic process of malignant tumors requires the expression and activation of proteolytic enzymes which facilitate the progression of tumor cells in different ways. Among these proteolytic enzymes, collagenase-3 (matrix metalloproteinase-13) is a recently identified member of the MMP family, and is expressed in breast carcinomas and in articular cartilage from arthritic patients. The substrate specificity of MMP-13 is exceptionally wide as compared to other MMPs.
Materials and Methods: We performed immunohistochemical stains on 10 normal mucosas and 35 SCCs of the head and neck with anticollagenase-3 antibody and analysed the staining patterns.
Results: As a result, the expression of the MMP-13 were detected in 23 of the 35 SCCs(66%), but no expression was detected in any of the 10 normal mucosa. The expression of MMP-13 in most tumors was localized predominantly in neoplastic cells at the invading periphery of the tumor (74% ; 17/23). A significant correlation was found between MMP-13 expression and local tumor invasion but no correlation was observed between expression and the age, sex of the patients, histological grade, lymph node metastases, recurrence, or the stage of the tumors.
Conclusion: These findings suggest that MMP-13 expression may contribute to the progression of a significant subset in SCCs of the head and neck. In the future, it is likely that elucidation of the regulatory mechanisms of the MMP-13 in SCCs may prove to be beneficial in developing novel therapeutic modalities for preventing invasion of these neoplastic cells.
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