Recombinant canine matrix metalloproteinase-13: Expression, functional characterization and application in sandwich ELISA for canine mammary carcinoma detection.

Matrix metalloproteinase-13 (MMP-13), a key regulator of extracellular matrix remodeling, has been implicated in tumor invasion and metastasis. This study investigated MMP-13 expression in canine mammary carcinomas and evaluated its diagnostic potential. MMP-13 mRNA and protein expression were assessed by quantitative real-time PCR and immunohistochemistry, respectively. Compared with healthy mammary tissues (n = 10), CMT tissues (n = 27) exhibited a significant 6.63 ± 0.70-fold upregulation of MMP-13 transcripts (p ≤ 0.05). A recombinant canine MMP-13 was produced (55 kDa approx.), functionally validated by zymography and cell invasion assay, and used to develop a sandwich ELISA. The assay demonstrated excellent diagnostic performance, distinguishing tumor-bearing dogs from healthy controls with an area under the receiver operating characteristic curve of 0.968, 96.30% sensitivity, and 88.60% specificity. Immunohistochemistry showed strong MMP-13 expression in 70.37% of canine mammary carcinomas. These findings demonstrate that MMP-13 is overexpressed in canine mammary carcinomas and suggest that MMP-13 protein has the potential to serve as an additional candidate biomarker for the detection of canine mammary carcinomas. However, further validation in a larger set of samples is warranted.