Insulin-like growth factor (IGF) binding to a murine mammary epithelial cell line

✍ Scribed by Darryl L. Hadsell; C. Anne Gibson; Craig R. Baumrucker

• Book ID: 102886432
• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 670 KB
• Volume: 161
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1041610306

✦ Synopsis

The goal of this study was to relate insulin-like growth factor (IGF) binding with IGF-stimulated growth in a murine mammary epithelial (COMMA-DIMME) cell line. Affinity crosslinking with ['2'1]IGF-I showed major bands at 224,000 and 148,000 M r that were ablated by the inclusion of IGF-I or -11 at 130 nM. Scatchardtransformed ['L51]lGF-l binding data was best fit by a two-site model, with 24,000 sites possessing a Kd of 0.33 n M and 1,000 sites possessing a Kd of 8.09 n M per cell. Competition analysis showed ED, , values for IGF-I, -11, and insulin to be 0.90 ? 0.03, 7.1 5 ? 4.27, and 335 * 104 nM, respectively. Affinity crosslinking of ['L51]1GF-II showed three major bands of 230,000, 148,000, and 61,000 to 58,000 Mr. Unlabeled IGF-II ablated all bands, while IGF-I and insulin ablated only the 148,000 Mr band. Competition analysis showed ED, , values for unlabeled IGF-I and -11 to be 0.10 ? 0.01 and 5.31 2 2.04 nM, respectively. In spite of the receptor affinity differences, no significant difference was noted in IGF-I and -11 in capacity to stimulate cell growth. These data indicate that COMMA-DlMME cells express IGF receptors and that both IGFs are mitogenic.