Inhibition of epidermal growth factor binding to cultured mouse epidermal cells by tumor promoters.
The tumor promotor 12-O-tetradecanoylphorbol-13-acetate (TPA) caused partial inhibition of the binding of [125I]epidermal growth factor ([125I]EGF) to intact mouse epidermal cells (HEL/37). The proportion of [125I]EGF binding which was insensitive to TPA inhibition decreased with increasing EGF concentration. The partial inhibition of [125I]EGF binding was not due to destruction of TPA or to covalent linkage of EGF to receptor sites. The binding of [125I]EGF to HEL/37 cells showed a curvilinear Scatchard plot; this was converted into a linear plot in the presence of TPA. We conclude that TPA acts to inhibit interactions between EGF receptors or between EGF receptors and some other membrane component(s).
Murray
A W
AW
School of Biological Sciences, Flinders University of South Australia, Bedford Park, Australia.
Froscio
M
M
D000818:Animals; D002273:Carcinogens / Q000494:pharmacology*; D003864:Depression, Chemical; D000078404:Epidermal Cells; D004815:Epidermal Growth Factor / Q000378:metabolism*; D004817:Epidermis / Q000187:drug effects*; D066246:ErbB Receptors / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D010703:Phorbol Esters / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D013755:Tetradecanoylphorbol Acetate / Q000031:analogs & derivatives* / Q000494:pharmacology
D002273:Carcinogens; D010703:Phorbol Esters; C008876:phorbol-12,13-didecanoate; C020922:4-O-methyl-12-O-tetradecanoylphorbol 13-acetate; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D013755:Tetradecanoylphorbol Acetate