ABSTRACT
BACKGROUND: Histone lysine demethylases (KDMs) are of interest as drug targets due to their regulatory roles in chromatin organization and their tight associations with diseases including cancer and mental disorders. The first KDM inhibitors for KDM1 have entered clinical trials, and efforts are ongoing to develop potent, selective and cell-active 'probe' molecules for this target class. Robust cellular assays to assess the specific engagement of KDM inhibitors in cells as well as their cellular selectivity are a prerequisite for the development of high-quality inhibitors. Here we describe the use of a high-content cellular immunofluorescence assay as a method for demonstrating target engagement in cells. RESULTS: A panel of assays for the Jumonji C subfamily of KDMs was developed to encompass all major branches of the JmjC phylogenetic tree. These assays compare compound activity against wild-type KDM proteins to a catalytically inactive version of the KDM, in which residues involved in the active-site iron coordination are mutated to inactivate the enzyme activity. These mutants are critical for assessing the specific effect of KDM inhibitors and for revealing indirect effects on histone methylation status. The reported assays make use of ectopically expressed demethylases, and we demonstrate their use to profile several recently identified classes of KDM inhibitors and their structurally matched inactive controls. The generated data correlate well with assay results assessing endogenous KDM inhibition and confirm the selectivity observed in biochemical assays with isolated enzymes. We find that both cellular permeability and competition with 2-oxoglutarate affect the translation of biochemical activity to cellular inhibition. CONCLUSIONS: High-content-based immunofluorescence assays have been established for eight KDM members of the 2-oxoglutarate-dependent oxygenases covering all major branches of the JmjC-KDM phylogenetic tree. The usage of both full-length, wild-type and catalytically inactive mutant ectopically expressed protein, as well as structure-matched inactive control compounds, allowed for detection of nonspecific effects causing changes in histone methylation as a result of compound toxicity. The developed assays offer a histone lysine demethylase family-wide tool for assessing KDM inhibitors for cell activity and on-target efficacy. In addition, the presented data may inform further studies to assess the cell-based activity of histone lysine methylation inhibitors.
Subject(s)
Enzyme Inhibitors/metabolism , Histone Demethylases/antagonists & inhibitors , Apoptosis/drug effects , Biocatalysis , Catalytic Domain , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , HeLa Cells , Histone Demethylases/genetics , Histone Demethylases/metabolism , Histones/metabolism , Humans , Inhibitory Concentration 50 , Methylation/drug effects , Microscopy, Fluorescence , Mutagenesis , Paclitaxel/toxicity , Phylogeny , Protein Isoforms/antagonists & inhibitors , Protein Isoforms/genetics , Protein Isoforms/metabolism , Protein Stability/drug effectsABSTRACT
The 2-oxoglutarate-dependent dioxygenase target class comprises around 60 enzymes including several subfamilies with relevance to human disease, such as the prolyl hydroxylases and the Jumonji-type lysine demethylases. Current drug discovery approaches are largely based on small molecule inhibitors targeting the iron/2-oxoglutarate cofactor binding site. We have devised a chemoproteomics approach based on a combination of unselective active-site ligands tethered to beads, enabling affinity capturing of around 40 different dioxygenase enzymes from human cells. Mass-spectrometry-based quantification of bead-bound enzymes using a free-ligand competition-binding format enabled the comprehensive determination of affinities for the cosubstrate 2-oxoglutarate and for oncometabolites such as 2-hydroxyglutarate. We also profiled a set of representative drug-like inhibitor compounds. The results indicate that intracellular competition by endogenous cofactors and high active site similarity present substantial challenges for drug discovery for this target class.
Subject(s)
Dioxygenases/metabolism , Ketoglutaric Acids/metabolism , ProteomicsABSTRACT
We report the discovery of N-substituted 4-(pyridin-2-yl)thiazole-2-amine derivatives and their subsequent optimization, guided by structure-based design, to give 8-(1H-pyrazol-3-yl)pyrido[3,4-d]pyrimidin-4(3H)-ones, a series of potent JmjC histone N-methyl lysine demethylase (KDM) inhibitors which bind to Fe(II) in the active site. Substitution from C4 of the pyrazole moiety allows access to the histone peptide substrate binding site; incorporation of a conformationally constrained 4-phenylpiperidine linker gives derivatives such as 54j and 54k which demonstrate equipotent activity versus the KDM4 (JMJD2) and KDM5 (JARID1) subfamily demethylases, selectivity over representative exemplars of the KDM2, KDM3, and KDM6 subfamilies, cellular permeability in the Caco-2 assay, and, for 54k, inhibition of H3K9Me3 and H3K4Me3 demethylation in a cell-based assay.
Subject(s)
Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Jumonji Domain-Containing Histone Demethylases/antagonists & inhibitors , Nuclear Proteins/antagonists & inhibitors , Pyrimidinones/chemistry , Pyrimidinones/pharmacology , Repressor Proteins/antagonists & inhibitors , Caco-2 Cells , Cell Membrane Permeability , Enzyme Inhibitors/pharmacokinetics , Humans , Jumonji Domain-Containing Histone Demethylases/chemistry , Jumonji Domain-Containing Histone Demethylases/metabolism , Nuclear Proteins/chemistry , Nuclear Proteins/metabolism , Pyrimidinones/pharmacokinetics , Repressor Proteins/chemistry , Repressor Proteins/metabolismABSTRACT
Optimization of KDM6B (JMJD3) HTS hit 12 led to the identification of 3-((furan-2-ylmethyl)amino)pyridine-4-carboxylic acid 34 and 3-(((3-methylthiophen-2-yl)methyl)amino)pyridine-4-carboxylic acid 39 that are inhibitors of the KDM4 (JMJD2) family of histone lysine demethylases. Compounds 34 and 39 possess activity, IC50 ≤ 100 nM, in KDM4 family biochemical (RFMS) assays with ≥ 50-fold selectivity against KDM6B and activity in a mechanistic KDM4C cell imaging assay (IC50 = 6-8 µM). Compounds 34 and 39 are also potent inhibitors of KDM5C (JARID1C) (RFMS IC50 = 100-125 nM).
Subject(s)
Enzyme Inhibitors/chemistry , Histone Demethylases/antagonists & inhibitors , Jumonji Domain-Containing Histone Demethylases/antagonists & inhibitors , Pyridines/chemistry , Amination , Cell Line , Cell Membrane Permeability , Crystallography, X-Ray , Drug Design , Enzyme Inhibitors/pharmacokinetics , Enzyme Inhibitors/pharmacology , Histone Demethylases/chemistry , Histone Demethylases/metabolism , Humans , Jumonji Domain-Containing Histone Demethylases/chemistry , Jumonji Domain-Containing Histone Demethylases/metabolism , Models, Molecular , Pyridines/pharmacokinetics , Pyridines/pharmacologyABSTRACT
Following the discovery of cell penetrant pyridine-4-carboxylate inhibitors of the KDM4 (JMJD2) and KDM5 (JARID1) families of histone lysine demethylases (e.g., 1), further optimization led to the identification of non-carboxylate inhibitors derived from pyrido[3,4-d]pyrimidin-4(3H)-one. A number of exemplars such as compound 41 possess interesting activity profiles in KDM4C and KDM5C biochemical and target-specific, cellular mechanistic assays.
Subject(s)
Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Histone Demethylases/antagonists & inhibitors , Jumonji Domain-Containing Histone Demethylases/antagonists & inhibitors , Pyrimidinones/chemistry , Pyrimidinones/pharmacology , Cell Line , Cell Membrane Permeability , Crystallography, X-Ray , Enzyme Inhibitors/pharmacokinetics , Histone Demethylases/chemistry , Histone Demethylases/metabolism , Humans , Jumonji Domain-Containing Histone Demethylases/chemistry , Jumonji Domain-Containing Histone Demethylases/metabolism , Models, Molecular , Molecular Docking Simulation , Pyrimidinones/pharmacokinetics , Structure-Activity RelationshipABSTRACT
Opioid receptors play an important role in both behavioral and homeostatic functions. We herein report tetrahydroquinoline derivatives as opioid receptor antagonists. SAR studies led to the identification of the potent antagonist 2v, endowed with 1.58nM (K(i)) functional activity against the µ opioid receptor. DMPK data suggest that novel tetrahydroquinoline analogs may be advantageous in peripheral applications.
Subject(s)
Narcotic Antagonists , Quinolines/chemistry , Quinolines/pharmacology , Receptors, Opioid/metabolism , Animals , CHO Cells , Cricetinae , Cricetulus , Humans , Quinolines/pharmacokinetics , Rats , Rats, Long-Evans , Structure-Activity RelationshipABSTRACT
Optimisation of a series of benzazepine sulfonamide hit compounds identified from high throughput screening led to the discovery of a new series of tractable, potent motilin receptor agonists.
Subject(s)
Receptors, Gastrointestinal Hormone/agonists , Receptors, Neuropeptide/agonists , Sulfonamides/pharmacology , Sulfones/pharmacology , Animals , Binding Sites , CHO Cells , Chemistry, Pharmaceutical , Cricetinae , Cricetulus , Drug Design , Drug Discovery , Models, Chemical , Molecular Structure , Structure-Activity RelationshipABSTRACT
N-(3-fluorophenyl)-1-[(4-([(3S)-3-methyl-1-piperazinyl]methyl)phenyl)acetyl]-4-piperidinamine 12 (GSK962040) is a novel small molecule motilin receptor agonist. It possesses excellent activity at the recombinant human motilin receptor and also at the native rabbit motilin receptor where its agonist activity results in potentiation of the amplitude of neuronal-mediated contractions of isolated gastric antrum tissue. Compound 12 also possesses highly promising pharmacokinetic profiles in both rat and dog, and these results, in combination with further profiling in human native tissue and an in vivo model of gastrointestinal transit in the rabbit, have led to its selection as a candidate for further development.
Subject(s)
Drug Discovery , Gastrointestinal Agents/pharmacology , Piperazines/pharmacology , Piperidines/pharmacology , Pyloric Antrum/drug effects , Receptors, Gastrointestinal Hormone/agonists , Receptors, Neuropeptide/agonists , Animals , Dogs , Gastrointestinal Motility/drug effects , Humans , Muscle Contraction/drug effects , Piperazines/chemistry , Piperidines/chemistry , Pyloric Antrum/physiology , Rabbits , RatsSubject(s)
Drug Design , Receptors, Gastrointestinal Hormone/drug effects , Receptors, Neuropeptide/drug effects , Animals , Humans , Receptors, Gastrointestinal Hormone/agonists , Receptors, Gastrointestinal Hormone/antagonists & inhibitors , Receptors, Neuropeptide/agonists , Receptors, Neuropeptide/antagonists & inhibitorsABSTRACT
High-throughput screening resulted in the identification of a series of novel motilin receptor agonists with relatively low molecular weights. The series originated from an array of biphenyl derivatives designed to target 7-transmembrane (7-TM) receptors. Further investigation of the structure-activity relationship within the series resulted in the identification of compound (22) as a potent and selective agonist at the motilin receptor.
Subject(s)
Receptors, Gastrointestinal Hormone/agonists , Receptors, Gastrointestinal Hormone/chemistry , Receptors, Neuropeptide/agonists , Receptors, Neuropeptide/chemistry , Animals , Binding Sites , Cell Membrane/metabolism , Chemistry, Pharmaceutical/methods , Combinatorial Chemistry Techniques , Drug Design , Drug Evaluation, Preclinical , Humans , Models, Chemical , Molecular Structure , Receptors, G-Protein-Coupled/metabolism , Recombinant Proteins/chemistry , Structure-Activity RelationshipABSTRACT
Optimisation of urea (5), identified from high throughput screening and subsequent array chemistry, has resulted in the identification of pyridine carboxamide (33) which is a potent motilin receptor agonist possessing favourable physicochemical and ADME profiles. Compound (33) has demonstrated prokinetic-like activity both in vitro and in vivo in the rabbit and therefore represents a promising novel small molecule motilin receptor agonist for further evaluation as a gastroprokinetic agent.
Subject(s)
Carbon/chemistry , Pyridines/chemistry , Receptors, Gastrointestinal Hormone/agonists , Receptors, Neuropeptide/agonists , Animals , Chemistry, Pharmaceutical/methods , Drug Design , Gastrins/chemistry , Humans , Inhibitory Concentration 50 , Kinetics , Models, Chemical , Pyridines/chemical synthesis , Pyridines/pharmacology , Rabbits , Rats , Receptors, Gastrointestinal Hormone/chemistry , Receptors, Neuropeptide/chemistryABSTRACT
6-Phenylnicotinamide (2) was previously identified as a potent TRPV1 antagonist with activity in an in vivo model of inflammatory pain. Optimization of this lead through modification of both the biaryl and heteroaryl components has resulted in the discovery of 6-(4-fluorophenyl)-2-methyl-N-(2-methylbenzothiazol-5-yl)nicotinamide (32; SB-782443) which possesses an excellent overall profile and has been progressed into pre-clinical development.
Subject(s)
Benzothiazoles/chemical synthesis , Chemistry, Pharmaceutical/methods , Niacinamide/analogs & derivatives , Niacinamide/chemical synthesis , TRPV Cation Channels/antagonists & inhibitors , TRPV Cation Channels/chemistry , Administration, Oral , Animals , Benzothiazoles/pharmacology , Capsaicin/chemistry , Cell Line , Drug Design , Guinea Pigs , Humans , Inflammation , Inhibitory Concentration 50 , Models, Chemical , Niacinamide/chemistry , Niacinamide/pharmacology , RatsSubject(s)
Analgesics/pharmacology , Pain/drug therapy , TRPV Cation Channels/agonists , TRPV Cation Channels/antagonists & inhibitors , Analgesics/chemistry , Analgesics/therapeutic use , Animals , Capsaicin/pharmacology , Humans , Pain/metabolism , Pain/physiopathology , TRPV Cation Channels/physiologyABSTRACT
Starting from the high throughput screening hit (3), novel N-tetrahydroquinolinyl, N-quinolinyl and N-isoquinolinyl carboxamides have been identified as potent antagonists of the ion channel TRPV1. The N-quinolinylnicotinamide (46) showed excellent potency at human, guinea pig and rat TRPV1, a favourable in vitro DMPK profile and activity in an in vivo model of inflammatory pain.
Subject(s)
Benzamides/chemistry , Benzamides/pharmacology , Isoquinolines/chemistry , Isoquinolines/pharmacology , Quinolines/chemistry , Quinolines/pharmacology , TRPV Cation Channels/antagonists & inhibitors , Animals , Benzamides/chemical synthesis , Capsaicin/pharmacology , Guinea Pigs , Humans , Isoquinolines/chemical synthesis , Liver/drug effects , Liver/metabolism , Molecular Structure , Quinolines/chemical synthesis , Rats , Structure-Activity Relationship , TRPV Cation Channels/metabolismABSTRACT
Bicyclic lactams derived from pyroglutamic acid provide a useful scaffold for synthesis of conformationally restricted analogues of lysine, ornithine and glutamine, as well as an Ala-Ala dipeptide analogue. Amino alcohol and carboxylic acid derivatives are accessible from a common intermediate. In this strategy, the bicyclic lactam system not only controls, but also facilitates the determination of the stereochemistry of the synthetic intermediates.