Effect of an anti-insulin-like growth factor I receptor antibody on insulin-like growth factor II stimulation of DNA synthesis in human fibroblasts.
To investigate the role of insulin-like growth factor II in the control of DNA synthesis in human fibroblasts, dose-response curves for insulin-like growth factor I and II stimulation of [3H]thymidine incorporation were compared in the absence and presence of alpha IR-3, a highly specific monoclonal antibody directed against the type I insulin-like growth factor receptor. Specific binding of [125I]insulin-like growth factor I to human fibroblast monolayer cultures was inhibited 60-70% in the presence of alpha IR-3. alpha IR-3 had no effect on [125I]insulin-like growth factor II binding to human fibroblasts. However, alpha IR-3 inhibited both insulin-like growth factor I and II stimulated [3H]thymidine incorporation. These data indicate that the type II insulin-like growth factor receptor does not function as a transducer of insulin-like growth factor II's mitogenic effect in human fibroblasts.
D000328:Adult; D000911:Antibodies, Monoclonal; D001667:Binding, Competitive; D004261:DNA Replication / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D011972:Receptor, Insulin / Q000276:immunology*; D017451:Receptors, Somatomedin; D013002:Somatomedins / Q000494:pharmacology*; D013936:Thymidine / Q000378:metabolism
D000911:Antibodies, Monoclonal; D017451:Receptors, Somatomedin; D013002:Somatomedins; D004815:Epidermal Growth Factor; D011972:Receptor, Insulin; D013936:Thymidine