title: A selective small-molecule nuclear factor-kappaB inhibitor from a high-throughput cell-based assay for "activator protein-1 hits".
abstract: NSC 676914 has been identified as a selective nuclear factor-kappaB (NF-kappaB) inhibitor that does not inhibit cell proliferation. This compound was originally identified in a high-throughput cell-based assay for activator protein-1 (AP-1) inhibitors using synthetic compound libraries and the National Cancer Institute natural product repository. NSC 676914 shows activity against NF-kappaB in luciferase reporter assays at concentrations much less than the IC50 for AP-1. A serum response element reporter used as a specificity control and indicator of cell proliferation was relatively insensitive to the compound. Pretreatment with NSC 676914 is here shown to repress 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced IkappaB-alpha phosphorylation and translocation of p65/50 to the nucleus but not the processing of p52 from p100, suggesting the inhibition of NF-kappaB regulator IKKbeta rather than IKKalpha. Inhibition of NF-kappaB activation occurred as a consequence of blocking phosphorylation of IKK. Induction of IkappaB-alpha phosphorylation by TPA was diminished by pretreatment of NSC 676914 even at 1.1 mumol/L. In contrast, kinases c-Jun-NH2-kinase and extracellular signal-regulated kinases 1 and 2, important for AP-1 activation, showed no significant repression by this compound. Furthermore, a Matrigel invasion assay with breast cancer cell lines and a transformation assay in mouse JB6 cells revealed that TPA-induced invasion and transformation responses were completely repressed by this compound. These results suggest that NSC 676914 could be a novel inhibitor having potential therapeutic activity to target NF-kappaB for cancer treatment or prevention.
authors.affiliation: Laboratory of Cancer Prevention, Gene Regulation Section, Molecular Targets Development Program, National Cancer Institute-Frederick, Room 187, Building 567, Frederick, MD 21702, USA. kangm@ncifcrf.gov
authors.forename: Moon-Il
authors.initials: MI
authors.lastname: Kang
authors.forename: Curtis J
authors.initials: CJ
authors.lastname: Henrich
authors.forename: Heidi R
authors.initials: HR
authors.lastname: Bokesch
authors.forename: Kirk R
authors.initials: KR
authors.lastname: Gustafson
authors.forename: James B
authors.initials: JB
authors.lastname: McMahon
authors.forename: Alyson R
authors.initials: AR
authors.lastname: Baker
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Young
authors.forename: Nancy H
authors.initials: NH
authors.lastname: Colburn
mesh_terms: D000970:Antineoplastic Agents / Q000302:isolation & purification* / Q000494:pharmacology / Q000627:therapeutic use; D001391:Azo Compounds / Q000494:pharmacology / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000473:pathology*; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004354:Drug Screening Assays, Antitumor; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D008954:Models, Biological; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000235:genetics; D010766:Phosphorylation / Q000187:drug effects; D054852:Small Molecule Libraries / Q000032:analysis*; D013379:Substrate Specificity; D013451:Sulfonic Acids / Q000494:pharmacology / Q000627:therapeutic use; D018808:Transcription Factor AP-1 / Q000037:antagonists & inhibitors* / Q000235:genetics; D014162:Transfection
chemical_list: C541012:2-(4-((4-amino-2-methylphenyl)diazenyl)phenylsulfonyl)ethanesulfonoperoxoic acid; D000970:Antineoplastic Agents; D001391:Azo Compounds; D020672:I-kappa B Proteins; D016328:NF-kappa B; D054852:Small Molecule Libraries; D013451:Sulfonic Acids; D018808:Transcription Factor AP-1