The putative somatostatin antagonist, cyclo-(7-aminoheptanoyl-Phe-D-Trp-Lys-Thr[BZL]), may act as potent antiproliferative agonist.
The cyclic somatostatin (SST) analogue, cyclo-(7-aminoheptanoyl-Phe-D-Trp-Lys-Thr[BZL]) (cSSTA), has been widely used as somatostatin antagonist. In the human neuroblastoma cell line SH-SY5Y the cyclopeptide acts as a somatostatin receptor agonist. Similar to SST, cSSTA inhibits cell proliferation, activates the protein tyrosine phosphatase SHP-2, and stimulates the activity of mitogen-activated protein kinase. These results suggest that in SH-SY5Y neuroblastoma cells somatostatin receptors may exist which exhibit altered antagonist binding properties.
Biological and Pharmaceutical Faculty, Institute of Biochemistry and Biophysics, Friedrich-Schiller-University Jena, Philosophenweg 12, D-07743 Jena, Germany.
Jörg
J
Stirnweis
Frank-D
FD
Boehmer
Claus
C
Liebmann
D004247:DNA / Q000096:biosynthesis; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects; D009447:Neuroblastoma / Q000188:drug therapy; D019384:Nucleic Acid Synthesis Inhibitors / Q000378:metabolism / Q000494:pharmacology; D017027:Protein Tyrosine Phosphatases / Q000187:drug effects / Q000378:metabolism; D017481:Receptors, Somatostatin / Q000037:antagonists & inhibitors*; D013004:Somatostatin / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors* / Q000378:metabolism* / Q000494:pharmacology
D019384:Nucleic Acid Synthesis Inhibitors; D017481:Receptors, Somatostatin; D013004:Somatostatin; C043820:cyclo(7-aminoheptanoylphenylalanyl-tryptophyl-lysyl-benzylthreonyl); D004247:DNA; D020928:Mitogen-Activated Protein Kinases; D017027:Protein Tyrosine Phosphatases