Different responses to EGF in two human carcinoma cell lines, A431 and UCVA-1, possessing high numbers of EGF receptors

摘要: Abstract EGF binding capacity was examined in 9 different human cell lines which were derived from colon, rectum and pancreas tumors. Among these lines, a pancreatic carcinoma line, UCVA-1, found to possess high number (0.9 × 10 6 /cell) of receptors. This is comparable that receptors vulva epidermoid A431 cells (2 /cell). However, it that, unlike cells, the growth UCVA-1 serum-containing serum-free conditions, not inhibited by EGF. The have receptor M r = 170 K two affinity types: d1 2 −9 d2 −8 M. are less susceptible proteolytic cleavage than those cells. In apparently processed via receptor-mediated endocytosis. membrane contained EGF-stimulated protein kinase as stimulation phosphorylation only ∼ 20% while over 100% A431. When angiotensin II used substrate, relative activity EGF-dependent tyrosine-specific 8 times membrane. mostly on for both lines. several other components ( 100 K, 80 72 65 K) readily detected These observations indicate receptor/protein relation differs suggests may be related growth-inhibitory effect seen