Expression of the FGFR1 gene in human breast-carcinoma cells

Fibroblast growth factors (FGF) constitute a family of at least 9 members which act through high-affinity tyrosine-kinase receptors encoded by 4 distinct genes. In humans, the FGFRI gene is located in chromosomal region 8pl2. Its amplification and expression were examined in a panel of 110 breast carcinoma samples by Southern- and Northern-blot analyses. FGFRI was amplified in 9% and overexpressed in about 15% of the tumors studied. In situ hybridization experiments were performed on tissue sections of normal breast and tumors with a high level of FGFRI expression. In both normal and tumoral tissues, FGFRI RNA was detected in the epithelial cells. Overexpression of FGFRI seems to be associated with small, well-differentiated diploid tumors. © 1994 Wiley-Liss, Inc.