Evidence for Alpha-Fetoprotein Receptors in the MCF-7 Human Breast Cancer Cell Line

Abstract Evidence is presented demonstrating the existence of receptors specific for alpha-fetoprotein (AFP) on the surface of the MCF7 human breast cancer cells. At 4°C, AFP bound to the surface of MCF7 cells and at 37°C receptor-mediated endocytosis of AFP occured. Binding experiments with 125 I-AFP, at 4°C, yielded a biphasic saturation curve. The Kd for the two binding sites was found by Scatchard analysis to be 1.5 × 10 -9 .M (n= 2000 sites/cell) and 2.2 × 10 -7 M (n = 320 000 sites|cell-), respectively.