relation: http://d-scholarship-dev.library.pitt.edu/22266/ title: The antisignaling agent SC-ααδ9, 4-(benzyl-(2-[(2,5- diphenyloxazole-4-carbonyl)amino]ethyl)carbamoyl)-2-decanoylaminobutyric acid, is a structurally unique phospholipid analogue with phospholipase C inhibitory activity creator: Vogt, A creator: Pestell, KE creator: Day, BW creator: Lazo, JS creator: Wipf, P description: Phospholipids and lipid second messengers mediate mitogenic signal transduction and oncogenesis, but there have been few successful examples of small molecules that affect biologically important phospholipid metabolism. Here we investigated the actions of a previously described antitumor agent, 4-(benzyl-(2-[(2,5-diphenyloxazole-4-carbonyl)amino]ethyl)carbamoyl) -2-decanoylaminobutyric acid (SC-ααδ9), which has antisignaling properties, on phospholipases. Although SC-ααδ9 had been shown to be a potent and selective inhibitor of the Cdc25 family of dual-specificity phosphatases, many of its cellular effects are not readily reconciled with phosphatase inhibition. Molecular modeling studies suggested that SC-ααδ9 shared several structural features with membrane phospholipids. Enzyme inhibition studies in vitro revealed that SC-ααδ9 was a potent inhibitor of phospholipase C (PLC; IC50 = 25 μM) but did not inhibit phospholipase D activity at concentrations up to 100 μM. In H-ras (Q61L)-transformed Rat-1 fibroblasts with constitutively elevated levels of phosphorylated extracellular signal-regulated kinase (Erk), SC-ααδ9 inhibited both proliferation and oncogenic Erk activation at concentrations that inhibited PLC in vitro. A SC-ααδ9 congener that lacked antiproliferative activity also did not inhibit PLC in vitro. In the PLC-dependent scratch wound healing model, SC-ααδ9 was 10-fold more potent than the phosphatidylcholine-specific PLC inhibitor D-609. We propose that the structural resemblance of SC-ααδ9 to phospholipids allows it to inhibit cellular PLC, thereby providing a possible molecular mechanism for SC-ααδ9's effects on oncogenic Erk activation. © 2002 American Association for Cancer Research. date: 2002-09-01 type: Article type: PeerReviewed format: text/plain language: en rights: attached identifier: http://d-scholarship-dev.library.pitt.edu/22266/1/licence.txt identifier: Vogt, A and Pestell, KE and Day, BW and Lazo, JS and Wipf, P (2002) The antisignaling agent SC-ααδ9, 4-(benzyl-(2-[(2,5- diphenyloxazole-4-carbonyl)amino]ethyl)carbamoyl)-2-decanoylaminobutyric acid, is a structurally unique phospholipid analogue with phospholipase C inhibitory activity. Molecular Cancer Therapeutics, 1 (11). 885 - 892. ISSN 1535-7163