Related Experiment Videos
Association Between Matrix Metalloproteinase-9 (MMP-9) Immunohistochemical Expression and Clinicopathological
J Pimenta1, D Moreira2, J Prada3
1Vasco da Gama University School (EUVG), Coimbra, Portugal; CIVG-Vasco da Gama Research Center, EUVG-Vasco da Gama University School, 3020-210 Coimbra, Portugal; CECAV - Veterinary and Animal Research Centre, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal; Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), Portugal.
Background:
Equine melanoma is one of the most important oncological diseases in horses and exhibits a distinct biological behavior compared with melanoma in other species. Matrix metalloproteinase-9 (MMP-9) has been associated with tumor aggressiveness and metastasis in human and canine melanoma, but its expression in equine melanoma remains unknown.
Aims/Objectives:
Evaluate the immunohistochemical expression of MMP-9 in equine melanomas and investigate its association with clinicopathological features.
Methods:
68 formalin-fixed, paraffin-embedded equine melanomas from 48 gray horses were evaluated immunohistochemically for MMP-9 expression. Associations between MMP-9 expression and clinicopathological variables were assessed, including histological classification, tumor size, excision interval, ulceration, circumscription, tumor localization, and stromal immunolabeling. Statistical significance was considered when p < 0.05.
Results:
Overall, 69.1% of melanomas exhibited low MMP-9 expression, 27.9% high expression, and 2.9% were negative. Malignant melanomas exhibited significantly higher MMP-9 expression than benign tumors (p = 0.04). Medium-sized tumors showed significantly higher MMP-9 expression than small tumors (p = 0.02). MMP-9 immunolabeling was positively correlated with excision interval (p = 0.03), and longer excision intervals were associated with histological malignancy (p < 0.001). No significant associations were identified between MMP-9 expression and ulceration, tumor circumscription, horse age, tumor localization, or number of tumors.
Conclusion:
This study provides the first immunohistochemical characterization of MMP-9 expression in equine melanoma. MMP-9 expression was predominantly low, but was significantly associated with histological malignancy, medium tumor size, and longer excision intervals. These findings may help to expand the current clinicopathological characterization of equine melanoma.
