title: Expression of matrix metalloproteinases, tissue inhibitors of metalloproteinases and vascular endothelial growth factor in canine mast cell tumours.
abstract: Degradation of the extracellular matrix and angiogenesis are associated with tumour invasion and metastasis in human and canine neoplasia. Matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs) and vascular endothelial growth factor-A (VEGF-A) are key mediators of these respective processes. Mast cell tumour (MCT) is the most common malignant cutaneous tumour in dogs. MCTs are always considered potentially malignant, but their true metastatic potential is unknown. In the present study, samples from seven grade 1, 22 grade 2 and six grade 3 MCTs were subjected to quantitative real-time polymerase chain reaction and immunohistochemistry (IHC) to evaluate MMP-2, MMP-9, membrane-type 1 MMP (MT1-MMP), TIMP-2 and VEGF-A mRNA and protein expression. Gelatin zymography (GZ) was also performed to evaluate MMP-2 and MMP-9 activity. MMP-9 and VEGF-A mRNA increased with histological grade, while TIMP-2 decreased with increasing grade. Gene expression data obtained for MMP-9, VEGF-A and TIMP-2 were confirmed by IHC for evaluation of the respective proteins. In contrast, MMP-2 and MT1-MMP had variable, but similar, expression for both mRNA and protein. Despite the high variability observed, there was correlation between MMP-2 and MT1-MMP mRNA expression (r=+0.91, P<0.0001). The MMP-2:TIMP-2 and MMP-9:TIMP-1 mRNA ratios showed an imbalance between MMPs and their specific inhibitors in MCTs, which increased with the histological grade. Finally, the activities of both latent and active forms of MMP-2 and MMP-9 were evaluated by GZ and there were significant increases in their activities with increasing histological grade and immunohistochemical expression. This study demonstrates that MMP-9, TIMP-2 and VEGF-A expression is related to histological grade and suggests that these markers are possible indicators of malignancy and targets for therapeutic strategies.
authors.affiliation: Dipartimento di Biomedicina Comparata e Alimentazione, Università degli Studi di Padova, viale Università 16, 35020 Legnaro, Padua, Italy. mery.giantin@unipd.it
authors.forename: M
authors.initials: M
authors.lastname: Giantin
authors.forename: L
authors.initials: L
authors.lastname: Aresu
authors.forename: S
authors.initials: S
authors.lastname: Benali
authors.forename: A
authors.initials: A
authors.lastname: Aricò
authors.forename: E M
authors.initials: EM
authors.lastname: Morello
authors.forename: M
authors.initials: M
authors.lastname: Martano
authors.forename: M
authors.initials: M
authors.lastname: Vascellari
authors.forename: M
authors.initials: M
authors.lastname: Castagnaro
authors.forename: R M
authors.initials: RM
authors.lastname: Lopparelli
authors.forename: V
authors.initials: V
authors.lastname: Zancanella
authors.forename: A
authors.initials: A
authors.lastname: Granato
authors.forename: F
authors.initials: F
authors.lastname: Mutinelli
authors.forename: M
authors.initials: M
authors.lastname: Dacasto
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D004273:DNA, Neoplasm / Q000032:analysis; D004283:Dog Diseases / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D004285:Dogs; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D007150:Immunohistochemistry; D008297:Male; D012515:Mast-Cell Sarcoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D020782:Matrix Metalloproteinases / Q000235:genetics* / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012333:RNA, Messenger / Q000378:metabolism; D012878:Skin Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D019714:Tissue Inhibitor of Metalloproteinases / Q000235:genetics* / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics* / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D012333:RNA, Messenger; D019714:Tissue Inhibitor of Metalloproteinases; D042461:Vascular Endothelial Growth Factor A; D020782:Matrix Metalloproteinases