Evidence for increased epidermal growth factor receptors in human sarcomas.

The results of an immunocytochemical study of the epidermal growth factor receptor (EGFR) in 35 human soft-tissue sarcomas, using a murine monoclonal antibody (MAb) EGF-R1, are reported. In many of the tumours staining was stronger than in the adjacent stroma, suggesting increased levels of receptor. Particularly strong staining was seen in one epithelioid sarcoma and in the spindle-cell component of a synovial sarcoma. Binding studies carried out on an epithelioid sarcoma cell line established from one of the specimens, using radiolabelled EGF, showed that approximately 8% of the receptors were of high affinity with a dissociation constant (KD) of approximately 10(-10)M, while the remainder were of lower affinity with a KD of 10(-9)M. The cells expressed a total of 1.7 X 10(6) receptors/cell which is equivalent to that found in some epidermoid tumours where gene amplification has been demonstrated. These data suggest that, as with other tumours recently reported, increased levels of epidermal growth factor receptor may be related to transformation.