ABSTRACT
The discovery of a highly potent and selective small molecule inhibitor 9 for in vitro target validation of MNK1/2 kinases is described. The aminopyrazine benzimidazole series was derived from an HTS hit and optimized by utilization of a docking model, conformation analysis, and binding pocket comparison against antitargets.
Subject(s)
Intracellular Signaling Peptides and Proteins/antagonists & inhibitors , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Binding Sites , Caco-2 Cells/drug effects , Drug Design , High-Throughput Screening Assays/methods , Humans , Intracellular Signaling Peptides and Proteins/chemistry , Intracellular Signaling Peptides and Proteins/metabolism , Molecular Docking Simulation , Permeability , Protein Serine-Threonine Kinases/chemistry , Protein Serine-Threonine Kinases/metabolism , Solubility , Structure-Activity RelationshipABSTRACT
Two scaffolds based on 5,6-fused heterocyclic backbones were designed and synthesized as Raf kinase inhibitors. The scaffolds were assessed for in vitro pan-Raf inhibition, activity in cell proliferation and target modulation assays, and pharmacokinetic parameters.
Subject(s)
Amides/chemical synthesis , Drug Design , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Heterocyclic Compounds/chemical synthesis , raf Kinases/antagonists & inhibitors , Amides/chemistry , Amides/pharmacology , Binding Sites , Cell Proliferation , Enzyme Activation/drug effects , Enzyme Inhibitors/chemistry , Heterocyclic Compounds/chemistry , Heterocyclic Compounds/pharmacology , Models, Molecular , Molecular Structure , Structure-Activity RelationshipABSTRACT
A series of arylaminobenzimidazoles was designed and synthesized as Raf kinase inhibitors. Exploration of the structure-activity relationship resulted in compounds that are potent in vitro and show desirable in vivo properties.
Subject(s)
Benzimidazoles/chemical synthesis , Benzimidazoles/pharmacology , Drug Design , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacology , raf Kinases/antagonists & inhibitors , Administration, Oral , Animals , Benzimidazoles/administration & dosage , Benzimidazoles/chemistry , Biological Availability , Cell Line, Tumor , Cell Proliferation/drug effects , Crystallography, X-Ray , Dose-Response Relationship, Drug , Female , Humans , Mice , Models, Molecular , Molecular Structure , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/chemistry , Protein Structure, Tertiary , Stereoisomerism , Structure-Activity Relationship , Xenograft Model Antitumor Assays , raf Kinases/metabolismABSTRACT
Apo2L/TRAIL exhibits enhanced apoptotic activity in tumor xenograft models when used in combination with the topoisomerase 1 inhibitor CPT-11. To investigate the cellular mechanisms involved in this increased tumor-killing activity, a series of in vitro experiments were conducted using the human colon carcinoma cell line (HCT116). Apo2L/TRAIL induced a transient upregulation of DR5 mRNA, while CPT-11 increased both death and decoy receptor expression. Upregulation of decoy receptors by CPT-11 was partially inhibited by co-administration of Apo2L/TRAIL. CPT-11 treatment resulted in accumulation of cells at G(2)M-phase and correlated with a substantial increase in the protein levels of the cyclin-dependent kinase inhibitor p21. However, cells co-treated with CPT-11 and Apo2L/TRAIL, or pretreated with CPT-11 for up to 24 h followed by 2 h Apo2L/TRAIL, resulted in a caspase-dependent degradation of p21, reversal of G(2)-M phase arrest with a concomitant increase in apoptosis. The sequential treatment produced the greatest induction of DR5 and DR4, caspase-3-like cleavage/activation and p21 degradation, as well as increased apoptosis. These data indicate that the up-regulation of Apo2L/TRAIL ligand and its death receptors as well as cleavage of p21 protein in the Apo2L/TRAIL plus CPT-11 treatment contributes to the positive cooperation between these agents in enhancing tumor cell apoptosis.
