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).
School of Biological Sciences, Flinders University of South Australia, Bedford Park, Australia.
A W
AW
Murray
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M
Froscio
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