title: Radioimmunoassay for human insulin-like growth factor-I receptor: applicability to breast carcinoma specimens and cell lines.
abstract: A radioimmunoassay for the human insulin-like growth factor-I (IGF-I) receptor was developed using a rabbit polyclonal antibody to the human IGF-I receptor and a highly purified IGF-I receptor. The purified receptor was radiolabeled with 125I-Bolton-Hunter reagent. Over 18% of the radiolabeled receptor was immunoprecipitated with the polyclonal antireceptor antibody. Purified IGF-I receptor concentrations as low as 5 ng/0.5 mL inhibited the radiolabeled IGF-I receptor binding. Purified insulin receptor weakly inhibited this binding, while the ligand IGF-I did not show inhibition. The radioimmunoassay was applicable to the measurements of IGF-I receptors in the Triton X-100 extracts of various tissues and cells. Breast cancer tissues and cells showed detectable IGF-I receptors, which correlated with IGF-I ligand binding. Receptor content was measurable in placenta and IM-9 cells, but receptor content was not measurable in liver and muscle extracts.
authors.affiliation: Cattedra di Endocrinologia, Università di Catania, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Pezzino
authors.forename: G
authors.initials: G
authors.lastname: Milazzo
authors.forename: L
authors.initials: L
authors.lastname: Frittitta
authors.forename: R
authors.initials: R
authors.lastname: Vigneri
authors.forename: O
authors.initials: O
authors.lastname: Ezaki
authors.forename: M
authors.initials: M
authors.lastname: Kasahara
authors.forename: T R
authors.initials: TR
authors.lastname: LeBon
authors.forename: I D
authors.initials: ID
authors.lastname: Goldfine
authors.forename: Y
authors.initials: Y
authors.lastname: Fujita-Yamaguchi
mesh_terms: D001667:Binding, Competitive; D001943:Breast Neoplasms / Q000378:metabolism*; D002277:Carcinoma / Q000378:metabolism*; D002460:Cell Line; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D011863:Radioimmunoassay / Q000379:methods*; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017451:Receptors, Somatomedin; D014020:Tissue Extracts / Q000378:metabolism
chemical_list: D011956:Receptors, Cell Surface; D017451:Receptors, Somatomedin; D014020:Tissue Extracts; D007334:Insulin-Like Growth Factor I