Appearance of basic fibroblast growth factor receptors upon differentiation of rat mammary epithelial to myoepithelial-like cells in culture.
The binding of [125I]-epidermal growth factor (EGF) and [125I]-basic fibroblast growth factor (bFGF) to a number of single-cell cloned rat mammary cell lines was measured using a saturation assay. Similar numbers of high-affinity [125I]-EGF binding sites (KD 1.3 nM) were found in epithelial and myoepithelial-like cell lines. In contrast, high-affinity (KD 35-276 pM) [125I]-bFGF binding sites were present on fibroblastic and myoepithelial-like cell lines but were not detectable on epithelial cell lines. A series of cell lines representing stages in the differentiation pathway of epithelial cells to an elongated myoepithelial-like morphology showed a graded increase in the number of bFGF receptors. The sensitivity of a cell line to stimulation of DNA synthesis by bFGF correlated with the level of expression of bFGF receptors on the cellular surface. Complexes of cell surface receptors affinity-cross-linked to [125I]-bFGF were analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). In each case two distinct complexes having apparent molecular weights of 180 kDa and 160 kDa were observed.
Fernig
D G
DG
Department of Biochemistry, University of Liverpool, England.
Smith
J A
JA
Rudland
P S
PS
D000818:Animals; D002454:Cell Differentiation; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000378:metabolism / Q000502:physiology; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism / Q000648:ultrastructure; D066246:ErbB Receptors / Q000378:metabolism; D005260:Female; D005346:Fibroblast Growth Factors / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology; D008321:Mammary Glands, Animal / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure*; D009132:Muscles / Q000166:cytology; D051381:Rats; D011919:Rats, Inbred Strains; D011920:Rats, Inbred WF; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017468:Receptors, Fibroblast Growth Factor; D013936:Thymidine / Q000378:metabolism
D011956:Receptors, Cell Surface; D017468:Receptors, Fibroblast Growth Factor; D005346:Fibroblast Growth Factors; D004815:Epidermal Growth Factor; D004247:DNA; D066246:ErbB Receptors; D013936:Thymidine