Abrogation of the mitogenic activity of bombesin by a cell surface sialoglycopeptide growth inhibitor.
The ability of a cell surface sialoglycopeptide (SGP) growth inhibitor to abrogate the mitogenic activity of bombesin, in serum-free medium, was investigated. The SGP was shown to be a potent antagonist of bombesin-induced DNA synthesis as 2.7 nM of the inhibitor completely blocked the mitogenic activity of 5.0 nM of bombesin. Exposure of 3T3 cells to bombesin for only 10 hr was sufficient to initiate the induction of DNA synthesis 10 hr later. Kinetic studies demonstrated that the SGP was able to block bombesin-induced DNA synthesis only when added within 2 hr after exposure of the cells to the mitogen. The SGP inhibitor blocked bombesin mitogenesis at a post-receptor, intracellular, early event in the signal cascade.
Johnson
T C
TC
Division of Biology, Kansas State University, Manhattan 66506.
Sharifi
B G
BG
D000818:Animals; D001667:Binding, Competitive; D001839:Bombesin / Q000037:antagonists & inhibitors*; D002460:Cell Line; D004247:DNA / Q000096:biosynthesis; D006020:Glycopeptides / Q000494:pharmacology*; D006131:Growth Inhibitors / Q000494:pharmacology*; D066298:In Vitro Techniques; D007700:Kinetics; D051379:Mice; D012795:Sialoglycoproteins / Q000494:pharmacology*
D006020:Glycopeptides; D006131:Growth Inhibitors; D012795:Sialoglycoproteins; D004247:DNA; D001839:Bombesin