ISSN:
0021-9541
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
The goal of this study was to relate insulin-like growth factor (IGF) binding with IGF-stimulated growth in a murine mammary epithelial (COMMA-D/MME) cell line. Affinity crosslinking with [125I]IGF-I showed major bands at 224,000 and 148,000 Mr that were ablated by the inclusion of IGF-I or -II at 130 nM. Scatchard-transformed [125I]IGF-I binding data was best fit by a two-site model, with 24,000 sites possessing a Kd of 0.33 nM and 1,000 sites possessing a Kd of 8.09 nM per cell. Competition analysis showed ED50 values for IGF-I, -II, and insulin to be 0.90 ± 0.03, 7.15 ± 4.27, and 335 ± 104 nM, respectively. Affinity crosslinking of [125I]IGF-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 ED50 values for unlabeled IGF-I and -II to be 0.10 ± 0.01 and 5.31 ± 2.04 nM, respectively. In spite of the receptor affinity differences, no significant difference was noted in IGF-I and -II in capacity to stimulate cell growth. These data indicate that COMMA-D/MME cells express IGF receptors and that both IGFs are mitogenic. © 1994 Wiley-Liss, Inc.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcp.1041610306
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