INSULIN-RECEPTOR OVEREXPRESSION IN 184B5 HUMAN MAMMARY EPITHELIAL-CELLS INDUCES A LIGAND-DEPENDENT TRANSFORMED PHENOTYPE

To determine the role of the insulin receptor overexpression in breast epithelial cell transformation, the 184B5 hu man breast epithelial ce ll line was transfected with human insulin receptor cDNA. In two cell lines transfected with and overexpressing human insulin receptors (IR) (223.8 and 184.5 ng IR/10(6) cells), but not in untransfected cells, insulin binding and tyrosine kinase activity were elevated, and insuli n induced a dose-dependent increase in colony formation in soft agar. (C) 1995 Wiley-Liss, Inc.