VEGF concentration from plasma-activated platelets rich correlates with microvascular density and grading in canine mast cell tumour spontaneous model

Canine cutaneous mast cell tumours(CMCT) is a common cutaneous tumour in dog whit a higher incidencethan in human. CMCT is classified in threesubgroups, well and intermediately differentiated (G1 and G2), corresponding to a benign disease, and poorly differentiated (G3), corresponding to a malignant disease, which metastasize to lymph nodes, lives, spleen and bone marrow. In this study, we have evaluated serum (S), platelet-poor plasma (P-PP), plasma-activated platelet rich (P-APR) and cytosol vascular endothelial growth factor(VEGF) concentrations, microvascular density (MDV) and mast cell density (MCD)in a series of 86 CMCTs and we have correllated these parameters with each other, by means of ELISA detection of VEGF and immunohistochemistry. Results show that VEGF level from cytosol P-APR and MVD were significantly higher in G3 CMCTs as comparated to G1 or G2 subgroups. Moreover, a significantly strong correlation among VEGF levels from P-PAR and cytosol, MVD and MCD was found in G3 subgroup. Because VEGF levels from P-APR well correlated with MVD and malignancy grade in CMCT, we suggest that VEGF might be secreted from MCs and it may be a suitable surrogate inter-species angiogenetic markers of tumour progression in CMCT. Finally, CMCT seems to be a useful model to study the role of MCs in tumour angiogenesis and inhibitio of MCs degranulatio or activation might be a new anti-angiogenic strategy worthy to further investigations.