Different epidermal growth factor growth responses and receptor levels in human colon carcinoma cell lines

摘要: The growth response to epidermal factor (EGF) and the numbers types of EGF receptors were studied in three human colon tumor cell lines from each two groups that differ markedly their properties extent differentiation. Aggressively growing poorly differentiated cells (group I) did not respond alone, while less aggressively more III) responded with increased when was added chemically defined, serum-free medium. average number (EGF-R) measured at surface group III by radioligand binding assays, eight-fold higher than for I lines. These observations provide evidence possible autocrine mechanisms maintain available EGF-R levels down-regulate cells.