Immunohistochemical Study of MMP-9 Expression in Canine Malignant Mammary Tumors

Abstract

A class of proteinases called matrix metalloproteinases (MMPs) is involved in the breakdown of the extracellular matrix (ECM) as well as other biological activities. Due to their capacity to degrade the matrix, they were considered in the invasion and metastasis of tumors. The primary goal of this study is to evaluate the association between MMP-9 expression in tumor-adjacent stromal cells and malignant mammary tumors in dogs, as well as the potential use of this protease as a predictive tumor marker. During surgery and necropsy, 32 canine malignant mammary gland tumors were discovered. For histopathological grading of tumors, the Pena et al. [1], approach and the Goldsmith et al. [2], method were employed. Utilizing immunohistochemical labeling, epithelial and stromal cell MMP-9 expression was identified. The level of tumor malignancy was associated with the degree of MMP-9 expression in stromal cells. In addition, stromal cells had much greater levels of MMP-9 expression. The expression of MMP-9 was well distributed and intense in all grade II and III carcinomas as well as poorly differentiated carcinosarcomas. High histologic grade tumors have greater levels of MMP-9 expression, according to semiquantitative examination of the gene’s expression. This finding lends credence to the concept that MMP-9 functions as an ECM component in tumor invasion and metastasis.