IMMUNOHISTOCHEMICAL STUDY OF OVEREXPRESSION OF FIBROBLAST GROWTH-FACTOR-I (FGF-1), FGF-2, AND FGF RECEPTOR-1 IN HUMAN-MALIGNANT SALIVARY-GLAND TUMORS

Fibroblast growth factor-1 (FGF-1) and FGF-2 are broad spectrum mitoge ns. The expression of FGF-1, FGF-2, and their receptor, FGF receptor-1 (FGFR-1), was examined in malignant salivary gland tumours and normal salivary glands, using immunohistochemical methods. In seven cases of adenoid cystic carcinoma (ACC), both duct-like cells and modified myo epithelial cells were apparently immunopositive for FGF-1, FGF-2, and FGFR-1. In five cases of mucoepidermoid carcinoma (MC), all three type s of tumour cells including epidermoid cells, mucous cells, and interm ediate cells expressed immunoreactive FGF-1, FGF-2, and FGFR-1. In the se malignant salivary gland tumours, increased expression of FGFR-1 co rrelated with the intensity of both FGF-1 and FGF-2 immunoreactivity. In contrast to malignant salivary gland tumours, eight cases of normal salivary gland showed negative immunostaining for FGF-1, FGF-2, and F GFR-1 while four cases were weakly immunoreactive for FGF and its rece ptor. These results demonstrate that malignant salivary gland tumours overexpress FGF-1, FGF-2, and FGFR-1 compared with normal salivary gla nds and suggest that these growth factors may play an important role i n facilitating neoplastic progression in human salivary glands.