Matrix Metalloproteinase 11 is Overexpressed in Various Histotypes of Canine Mammary Tumors

Matrix metalloproteinase 11 (MMP-11) belongs to the family of matrix metalloproteinases whose serum level has been reported to be elevated in dogs with mammary tumors. The present investigation focuses on assessing the tissue level expression of MMP-11 in various histotypes of canine mammary tumors (CMT). In this study, 20 CMT tissue paraffin blocks preserved in the laboratory were used. Slides were prepared for histopathological examination and immunohistochemistry. Hyperimmune serum raised against the canine recombinant MMP-11 (rMMP-11) in mice was used to standardize immunohistochemistry to assess expression of MMP-11 protein in various histotypes of CMT. Based on the histopathological examination of hematoxylin and eosin (H&E)-stained tissue sections, the CMT tissues were classified into complex carcinoma, mixed mammary tumor, papillary carcinoma and anaplastic carcinoma. A strong MMP-11 expression was observed in 75% of the histotypes of CMT under study. The findings suggest that MMP-11 could act as molecular marker for the immunohistochemistry-based diagnosis of mammary tumors in dogs.