The role of FGF-2/HGF and fibronectin matrix on pleomorphic adenoma myoepithelial cell morphology and immunophenotype: an in vitro study

Myoepithelial cells play a central role in glandular tumors, regulating the progression of in situ to invasive neoplasias, with the tumor microenvironment being shown to be involved in both initiation and progression. This study aimed to analyze the in vitro effects of fibroblast growth factor-2 (FGF-2) and hepatocyte growth factor (HGF) in myoepithelial cells under the influence of the fibronectin matrix extracellular protein. Benign myoepithelial cells were obtained from pleomorphic adenoma and cultured on a fibronectin substratum. FGF-2 and HGF were supplemented at different concentrations and time intervals, in order to evaluate cell proliferation, morphology and immunophenotype. Individually, FGF-2 and HGF supplementation did not alter myoepithelial cell proliferation, morphology or immunophenotype. The fibronectin substratum provoked an increase in cell proliferation and immunopositivity for a-smooth muscle actin and FGF-2. The myoepithelial cell morphology changed when the fibronectin substratum and FGF-2 acted together, highlighting the importance of the fibronectin extracellular matrix protein on the behavior of these cells.