EXPRESSION OF BASIC FIBROBLAST GROWTH-FACTOR AND ITS RECEPTORS BY HEAD AND NECK SQUAMOUS CARCINOMA TUMOR AND VASCULAR ENDOTHELIAL-CELLS

BACKGROUND: Basic fibroblast growth factor (bFGF) is a potent angiogen ic factor implicated in tumor growth and metastasis. To determine if b FGF and basic fibroblast growth factor receptor 1 (bFGFR1) and 2 (bFGF R2) are upregulated in head and neck squamous cell carcinoma (HNSCC), we measured the distribution and levels of each in HNSCC specimens and control specimens. METHODS: Head and neck squamous cell carcinoma and control tissue specimens were analyzed qualitatively (40 patients, 10 controls) using immunohistochemistry, and quantitatively (26 patients , 8 controls) using immunoassays and graded immunohistochemistry. Cont rol tissue consisted of palatal tissue obtained during uvulopalatophar yngoplasty (UPPP). RESULTS: Immunohistochemical analysis revealed that bFGF, bFGFR1, and bFGFR2 antigens were strongly associated with cance r and vascular endothelial cells in HNSCC. Control tissue had moderate staining of vascular endothelium and no stromal staining. Quantitativ e analysis of bFGF in tissue homogenates indicated that bFGF levels in cancer specimens were significantly elevated compared with control ti ssues (420.3 +/- 360.9 ng/mg total protein versus 49.2 +/- 48.7, respe ctively, P less than or equal to 0.05). When analyzed by clinical stag e, bFGF levels were significantly higher in stage III patients as comp ared with stage IV patients (P less than or equal to 0.01). When immun ohistochemistry results were correlated with clinical stage, bFGF (P l ess than or equal to 0.01), bFGFR1 (P less than or equal to 0.001), an d bFGFR2 (P less than or equal to 0.0001) staining was significantly m ore intense in the cancer cells of stage III versus stage IV patients. CONCLUSION: Enhanced expression of bFGF and bFGF receptors by cancer and vascular endothelial cells is present in HNSCC, and may contribute to tumor growth and metastasis in HNSCC by mediating angiogenesis. St rategies aimed at decreasing the expression of bFGF and its receptors may be of therapeutic benefit in HNSCC, particularly at an early stage of disease, (C) 1997 by Excerpta Medica, Inc.