title: The tumor-selective somatostatin analog, TT2-32 induces a biphasic activation of phosphotyrosine phosphatase activity in human colon tumor cell line, SW620.
abstract: Somatostatin has been demonstrated to activate phosphotyrosine phosphatases (PTPases) in pancreatic cells. In this work we studied the effect of a tumor-selective somatostatin structural derivative, TT2-32, on the PTPase activity in the SW620 human colon tumor cell line. TT2-32 caused a strong inhibition of cell proliferation. In response to TT2-32 we found a rapid and sustained increase (5-30 min) in PTPase activity showing two maxima at 0.1 and 30 microM concentrations, respectively. During short-term incubation tyrosine kinase activity was much less affected by TT2-32. TT2-32-induced activation of PTPases may be an important early step in the signaling cascade in the inhibition of cell proliferation in colon carcinomas.
authors.affiliation: Department of Biochemistry 1, Joint Research Organisation of Hungarian Academy of Sciences, Semmelweis Medical University, Budapest.
authors.forename: T
authors.initials: T
authors.lastname: Vántus
authors.forename: P
authors.initials: P
authors.lastname: Csermely
authors.forename: I
authors.initials: I
authors.lastname: Teplán
authors.forename: G
authors.initials: G
authors.lastname: Kéri
mesh_terms: D000595:Amino Acid Sequence; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D008969:Molecular Sequence Data; D017027:Protein Tyrosine Phosphatases / Q000187:drug effects* / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013004:Somatostatin / Q000031:analogs & derivatives* / Q000494:pharmacology; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000201:enzymology
chemical_list: D000970:Antineoplastic Agents; C094462:TT2-32; D013004:Somatostatin; D011505:Protein-Tyrosine Kinases; D017027:Protein Tyrosine Phosphatases