A growth regulatory factor that can both inhibit and stimulate growth.
A growth inhibitor that is produced by BSC-1 cells (African green monkey kidney epithelial cells) has been isolated from conditioned medium. It has been purified by gel chromatography and high performance liquid chromatography. It appears to be a protein with a relative molecular mass (Mr) of 24 000. It is extremely active as a growth inhibitor with some cells, but not with others. Approximately 50% inhibition of thymidine incorporation is observed with CCL64 cells at 0.05 ng/ml and with BSC-1 cells at 1 ng/ml. The growth inhibitor induces BSC-1 cells to synthesize and secrete a glycoprotein of approximately 48 000 Mr. It inhibits Na+ accumulation in BSC-1 cells. Recently, in collaboration with R. F. Tucker, G.D. Shipley and H. L. Moses (Mayo Foundation & Medical School), we have found that the growth inhibitor is very similar to and may be identical with transforming growth factor beta (TGF-beta). Our growth inhibitor stimulates colony formation in soft agar by AKR-2B cells, and it competes with TGF-beta in binding to cell surface receptors. TGF-beta, from human platelets, is extremely active as an inhibitor of thymidine incorporation by BSC-1 cells and CCL64 cells. The growth inhibitor/TGF-beta can, therefore, stimulate or inhibit growth, depending on the cells and the growth conditions.
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002522:Chlorocebus aethiops; D002851:Chromatography, High Pressure Liquid; D003470:Culture Media; D004815:Epidermal Growth Factor / Q000494:pharmacology; D006131:Growth Inhibitors / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D010455:Peptides / Q000494:pharmacology; D014176:Protein Biosynthesis; D012964:Sodium / Q000378:metabolism; D015291:Transforming Growth Factors
D003470:Culture Media; D006131:Growth Inhibitors; D010455:Peptides; D004815:Epidermal Growth Factor; D015291:Transforming Growth Factors; D012964:Sodium