MSA and EGF receptors on saroma virus transformed cells and human fibrosarcoma cells in culture

It is demonstrated here that this sarcoma virus-dependent receptor loss is specific for EGF, and in two cell lines established from human fibrosarcomas, however, MSA binding was abolished while EGF bound to the same extent as to normal human fibroblasts.

Abstract

CULTURED cells transformed by murine or feline sarcoma viruses lose their ability to bind epidermal growth factor (EGF) to cell surface receptors, whereas cells transformed by DNA tumour viruses or infected with non-transforming RNA viruses show normal EGF binding1. We demonstrate here that this sarcoma virus-dependent receptor loss is specific for EGF. The binding of a different polypeptide growth factor, multiplication stimulating activity2–4 (MSA), to its cell surface receptors was not decreased in murine and feline sarcoma virus transformed cells. In two cell lines established from human fibrosarcomas, however, MSA binding was abolished while EGF bound to the same extent as to normal human fibroblasts.