Synthesis of basic fibroblast growth factor upon differentiation of rat mammary epithelial to myoepithelial-like cells in culture.
Acidic fibroblast growth factor (aFGF) mRNA was detected in a rat mammary fibroblastic cell line, but not in rat mammary epithelial cell lines or myoepithelial-like cell lines. Basic FGF (bFGF) mRNA was detected in both the fibroblasts and the myoepithelial-like cells, but was absent from the epithelial cells. A series of cell lines representing stages in the differentiation pathway of epithelial cells to a myoepithelial-like morphology showed an increase in the amount of bFGF mRNA and activity present and the FGF from the myoepithelial-like rat mammary 29 cells was able to displace [125I]-bFGF specifically bound to rat mammary fibroblasts. FGF activity was also present in an extract of rat mammary gland. Analysis of cell extracts and conditioned medium indicated that FGF activity was cell-associated. The cell-associated bFGF was resistant to degradation by trypsin. Extraction of myoepithelial-like cells with Triton X-100 and 2 M NaCl showed that 50-65% of the cell-associated bFGF was in a detergent-resistant but 2 M NaCl-labile structure. Thus, the synthesis of bFGF is developmentally regulated in rat mammary cell lines, and at least 50% is present in the extracellular matrix.
Barraclough
R
R
Department of Biochemistry, University of Liverpool, England.
Fernig
D G
DG
Rudland
P S
PS
Smith
J A
JA
D000818:Animals; D001483:Base Sequence; D001667:Binding, Competitive; D001923:Brain Chemistry; D002454:Cell Differentiation; D002460:Cell Line; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D005260:Female; D005346:Fibroblast Growth Factors / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D007700:Kinetics; D008321:Mammary Glands, Animal / Q000166:cytology* / Q000378:metabolism; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D015345:Oligonucleotide Probes; D009928:Organ Specificity; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D051381:Rats; D011956:Receptors, Cell Surface / Q000378:metabolism; D017468:Receptors, Fibroblast Growth Factor
D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D017468:Receptors, Fibroblast Growth Factor; D005346:Fibroblast Growth Factors