Basic fibroblast growth factor and angiogenesis in squamous carcinoma of the tongue S.S. Forootan a , Y. Ke a , A.S. Jones b , T.R. Helliwell a, * a Department of Pathology, University of Liverpool, Liverpool L69 3GA, UK b Department of Otolaryngology, University of Liverpool, Liverpool L69 3GA, UK Received 2 March 2000; accepted 7 March 2000 Abstract The relationship between basic fibroblast growth factor (bFGF), receptors for bFGF and neoangiogenesis was investigated in 51 patients with squamous cell carcinoma of the tongue, 26 of whom had metastatic disease in cervical lymph nodes. Vessels were demonstrated by immunocytochemical labelling for CD34 and expressed as raw counts and volume-weighted counts. bFGF protein and its receptors FGFR1(flg) and FGFR2(bek), were demonstrated using immunocytochemical labelling. In situ hybridisation for bFGF mRNA was performed using a 250-bp digoxigenin-labelled RNA probe. In normal epithelium, the expression of bFGF protein and mRNA was more intense in the basal layer, while receptors for bFGF were expressed more strongly in the superficial parts. In carcinomas, expression of bFGF was greater in the more poorly-dierentiated cells, but showed no relation to the overall tumour dierentiation. There was strong bFGF expression in tumour-infiltrating lymphocytes. The expression of bFGF receptors was variable, with FGFR2 being particularly high in areas of keratinisation. There were no consistent changes in bFGF or receptor expression between primary carcinomas and their lymph node metastases, and there was no correlation with measures of vascu- larity or tumour growth pattern. bFGF is synthesised by all squamous carcinomas and has the potential to modulate angiogenesis. However, these data suggest that changes in the expression of bFGF and its receptors are not related to the intensity of neoangio- genesis in lingual carcinomas or their nodal metastases. # 2000 Elsevier Science Ltd All rights reserved. Keywords: Squamous carcinoma; Tongue; Angiogenesis; Fibroblast growth factor; In situ hybridisation; Immunohistochemistry; Receptors 1. Introduction The clinical course and prognosis for groups of patients with squamous carcinoma of the oral cavity is mainly determined by the site, size and stage of the car- cinoma at diagnosis; however, for individual patients prediction is dicult. Although many potential mole- cular markers of prognosis have been studied, the rela- tionship between neoangiogenesis and growth factor expression has received little attention. Although neoangiogenesis promotes tumour growth and metastasis in several organs [1], previous studies of angiogenesis in squamous carcinomas of the head and neck have not demonstrated a consistent relationship between the density of microvessels and the presence of metastases or response to treatment [2–8]. These diver- gent results may be related in part to the small numbers of patients investigated, to the range of primary sites of the carcinomas, and to dierences in methodology, in particular the methods for describing the extent of neoangiogenesis [8]. Basic fibroblast growth factor (bFGF) is a potent angiogenic factor in normal and diseased tissues. Expression of bFGF protein has been described as higher in oral squamous carcinomas than in normal mucosa [9,10], with more intense expression in more poorly-dierentiated tumours [11], while others found no overexpression of bFGF in carcinomas and no correla- tion between vascularity and the expression of bFGF [12]. bFGF binds to low anity heparan sulphate pro- teoglycans which permit interaction with high anity receptors which mediate the cellular response to bFGF [13,14]. The FGF receptor family consist of four mem- bers which have 55–72% amino acid homology [15]. FGFR1(flg), FGFR2(bek) and FGFR4 are bound to membranes, while FGFR3 is found in nuclei [16]. In the present study, a series of squamous cell carci- nomas of the tongue was investigated using immuno- histochemistry and in situ hybridisation to provide information on the synthesis of bFGF and its potential 1368-8375/00/$ - see front matter # 2000 Elsevier Science Ltd All rights reserved. PII: S1368-8375(00)00032-4 Oral Oncology 36 (2000) 437–443 www.elsevier.com/locate/oraloncology * Corresponding author. Tel.: +44-151-706-4492; fax: +44-151- 706-5859. E-mail address: trh@liv.ac.uk (T.R. Helliwell).