An antibody to the receptor for insulin-like growth factor I inhibits the growth of MCF-7 cells in tissue culture.
Alpha IR-3, a monoclonal antibody to the insulin-like growth factor I receptor which blocks insulin-like growth factor I binding and inhibits its activity, inhibits the binding of 125I-insulin-like growth factor I to MCF-7 cells (an estrogen dependent human breast carcinoma cell line) with an IC-50 of approximately 100 ng/ml. It also inhibits the growth of MCF-7 cells cultured in 5% calf serum with approximately the same IC-50. Inhibition of growth occurs both when cells are cultured in the presence and absence of estrogen and is more pronounced when cells are grown at a low density. These findings demonstrate a requirement for insulin-like growth factor I for optimal growth of MCF-7 cells and suggest that it is an autocrine growth factor in these cells.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000502:physiology*; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D002452:Cell Count; D002455:Cell Division / Q000187:drug effects; D004958:Estradiol / Q000494:pharmacology; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D011972:Receptor, Insulin / Q000276:immunology / Q000502:physiology*; D017451:Receptors, Somatomedin; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D017451:Receptors, Somatomedin; D004958:Estradiol; D007334:Insulin-Like Growth Factor I; D011972:Receptor, Insulin