ABSTRACT
The clinical development of an inhibitor of cellular proteasome function suggests that compounds targeting other components of the ubiquitin-proteasome system might prove useful for the treatment of human malignancies. NEDD8-activating enzyme (NAE) is an essential component of the NEDD8 conjugation pathway that controls the activity of the cullin-RING subtype of ubiquitin ligases, thereby regulating the turnover of a subset of proteins upstream of the proteasome. Substrates of cullin-RING ligases have important roles in cellular processes associated with cancer cell growth and survival pathways. Here we describe MLN4924, a potent and selective inhibitor of NAE. MLN4924 disrupts cullin-RING ligase-mediated protein turnover leading to apoptotic death in human tumour cells by a new mechanism of action, the deregulation of S-phase DNA synthesis. MLN4924 suppressed the growth of human tumour xenografts in mice at compound exposures that were well tolerated. Our data suggest that NAE inhibitors may hold promise for the treatment of cancer.
Subject(s)
Antineoplastic Agents/pharmacology , Cyclopentanes/pharmacology , Enzyme Inhibitors/pharmacology , Neoplasms/drug therapy , Pyrimidines/pharmacology , Ubiquitin-Activating Enzymes/metabolism , Animals , Cell Line, Tumor , Cells, Cultured , Cullin Proteins/metabolism , Female , Humans , Mice , NEDD8 Protein , Proteasome Inhibitors , Transplantation, Heterologous , Ubiquitins/metabolismABSTRACT
The signaling pathways involving lipid kinase class I phosphatidylinositol 3-kinases (PI 3-kinases) regulate cell growth, proliferation, and survival. Class I PI 3-kinases catalyze the conversion of PI (4,5)P(2) to PI (3,4,5)P(3), which acts as a lipid second messenger to activate mitogenic signaling cascades. Recently, p110alpha, a class IA PI 3-kinase, was found to be mutated frequently in many human cancers. Therefore, it is increasingly studied as an anticancer drug target. Traditionally, PI 3-kinase activities have been studied using liposome substrates. This method, however, is hampered significantly by the labor-intensive manual lipid extraction followed by a low-throughput thin-layer chromatography analysis. The authors describe a high-throughput liposome substrate-based assay based on an automated lipid extraction method that allows them to study PI 3-kinase enzyme mechanism and quantitatively measure inhibitor activity using liposome substrates in a high-throughput mode. This improved assay format can easily be extended to study other classes of phosphoinositide lipid kinases.
Subject(s)
Liposomes/chemistry , Neoplasms/diagnosis , Phosphatidylinositol 3-Kinases/chemistry , Adenosine Triphosphate/chemistry , Automation , Biochemistry/methods , Chromatography, Thin Layer/methods , Humans , Inhibitory Concentration 50 , Kinetics , Lipids/chemistry , Neoplasms/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Phosphorylation , Signal Transduction , Substrate Specificity , Time FactorsABSTRACT
Substitution of phenyl oxazolidinones with carbon-linked azoles resulted in the discovery of a new class of potent oxazolidinones that have excellent Gram-positive activity. In addition, replacement of the C-5 acetamide side chains with a 4-methyl triazole diminished monoamine oxidase activity. The synthesis and biological evaluation of these compounds are reported.
Subject(s)
Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/pharmacology , Oxazolidinones/chemical synthesis , Oxazolidinones/pharmacology , Animals , Anti-Bacterial Agents/pharmacokinetics , Biological Availability , Colony Count, Microbial , Female , Gram-Positive Bacteria/drug effects , Half-Life , Humans , Liver/enzymology , Mice , Mice, Inbred C57BL , Microbial Sensitivity Tests , Monoamine Oxidase Inhibitors/chemical synthesis , Monoamine Oxidase Inhibitors/pharmacology , Pneumococcal Infections/drug therapy , Pneumococcal Infections/microbiology , Rats , Streptococcus pneumoniae/drug effects , Structure-Activity RelationshipABSTRACT
The barrier to rotation and hydrogen bonding interactions of 2,2-dicyano-1-(N,N'-dimethylamino)vinylbenzene (1) were studied in a range of solvents. The barrier to rotation of 1 in chloroform was 14.8 kcal/mol and increased by 1.7 kcal/mol in a protic solvent, trifluoroethanol. FTIR studies showed a shift in the cyano stretch of 1 to a higher wavenumber in trifluoroethanol, which is consistent with 1 participating in a hydrogen bonding interaction at the vinyl carbon (C(v)) of the enaminonitrile group.
