The role of the VEGF-C/-D/flt-4 autocrine loop in the pathogenesis of salivary neoplasms

Salivary gland cells produce and secrete VEGF under normal conditions, but this property has not been studied in salivary gland neoplasms. The aim of this study was to evaluate the expression of VEGF-C/VEGF-D/flt-4 in salivary gland tumors.Thirty-one salivary gland tumors (19 with and 12 without myoepithelial differentiation) were examined. Immunostaining for VEGF-C/VEGF-D/flt-4, p63 and SMA was carried out. The chi-square distribution and the Pearson correlation were applied.A statistically significant relationship (p < 0.05) was found in the group of tumors with myoepithelial differentiation regarding simultaneous positive staining for VEGF-C/VEGF-D and flt-4. All pleomorphic adenomas (PA) exhibited a statistically significant coexpression of the three antibodies. p63 and SMA were strongly expressed in the same areas as VEGF-C, VEGF-D and flt-4.The cells responsible for the strong expression of VEGF-C, VEGF-D and flt-4 in PAs are myoepithelial cells. Coexpression of flt-4 and its ligands in all PAs suggests the presence of a dominant VEGF-C/VEGF-D/flt-4 axis in this tumor.