ABSTRACT
In the last decades, inhibitors of histone deacetylases (HDAC) have become an important class of anti-cancer agents. In a previous study we described the synthesis of spiro[chromane-2,4'-piperidine]hydroxamic acid derivatives able to inhibit histone deacetylase enzymes. Herein, we present our exploration for new derivatives by replacing the piperidine moiety with various cycloamines. The goal was to obtain highly potent compounds with a good in vitro ADME profile. In addition, molecular modeling studies unravelled the binding mode of these inhibitors.
Subject(s)
Chromones/pharmacology , Histone Deacetylase Inhibitors/chemical synthesis , Histone Deacetylase Inhibitors/pharmacology , Histone Deacetylases/metabolism , Models, Molecular , Spiro Compounds/pharmacology , Chromones/chemical synthesis , Chromones/chemistry , Dose-Response Relationship, Drug , Histone Deacetylase Inhibitors/chemistry , Humans , Molecular Structure , Spiro Compounds/chemical synthesis , Spiro Compounds/chemistry , Structure-Activity RelationshipABSTRACT
In this account, we report the development of a series of substituted cinnamic anilides that represents a novel class of mitochondrial permeability transition pore (mPTP) inhibitors. Initial class expansion led to the establishment of the basic structural requirements for activity and to the identification of derivatives with inhibitory potency higher than that of the standard inhibitor cyclosporine-A (CsA). These compounds can inhibit mPTP opening in response to several stimuli including calcium overload, oxidative stress, and thiol cross-linkers. The activity of the cinnamic anilide mPTP inhibitors turned out to be additive with that of CsA, suggesting for these inhibitors a molecular target different from cyclophylin-D. In vitro and in vivo data are presented for (E)-3-(4-fluoro-3-hydroxy-phenyl)-N-naphthalen-1-yl-acrylamide 22, one of the most interesting compounds in this series, able to attenuate opening of the mPTP and limit reperfusion injury in a rabbit model of acute myocardial infarction.
Subject(s)
1-Naphthylamine/analogs & derivatives , Acrylamides/chemistry , Anilides/chemistry , Cinnamates/chemistry , Mitochondrial Membrane Transport Proteins/antagonists & inhibitors , Myocardial Reperfusion Injury/drug therapy , 1-Naphthylamine/chemical synthesis , 1-Naphthylamine/chemistry , 1-Naphthylamine/pharmacology , Acrylamides/chemical synthesis , Acrylamides/pharmacology , Anilides/chemical synthesis , Anilides/pharmacology , Animals , Calcium/metabolism , Cinnamates/chemical synthesis , Cinnamates/pharmacology , Female , Male , Mice, Inbred C57BL , Mitochondria, Heart/metabolism , Mitochondria, Liver/metabolism , Mitochondrial Membrane Transport Proteins/metabolism , Mitochondrial Permeability Transition Pore , Mitochondrial Swelling/drug effects , Myocardial Infarction/drug therapy , Myocardial Infarction/metabolism , Myocardial Reperfusion Injury/metabolism , Rabbits , Stereoisomerism , Structure-Activity RelationshipABSTRACT
Heat-shock protein 90 (Hsp90) is a molecular chaperone involved in the stabilization of key oncogenic signaling proteins, and therefore, inhibition of Hsp90 represents a new strategy in cancer therapy. 2-Amino-7-[4-fluoro-2-(3-pyridyl)phenyl]-4-methyl-7,8-dihydro-6H-quinazolin-5-one oxime is a racemic Hsp90 inhibitor that targets the N-terminal adenosine triphosphatase site. We developed a method to resolve the enantiomers and evaluated their inhibitory activity on Hsp90 and the consequent antitumor effects. The (S) stereoisomer emerged as a potent Hsp90 inhibitor in biochemical and cellular assays. In addition, this enantiomer exhibited high oral bioavailability in mice and excellent antitumor activity in two different human cancer xenograft models.
Subject(s)
Antineoplastic Agents/chemistry , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Oximes/chemistry , Quinazolinones/chemistry , Animals , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Binding Sites , Cell Line, Tumor , Female , HCT116 Cells , HSP90 Heat-Shock Proteins/metabolism , Humans , Mice , Mice, Nude , Microsomes/metabolism , Molecular Docking Simulation , Neoplasms/drug therapy , Oximes/pharmacology , Oximes/therapeutic use , Protein Binding/drug effects , Protein Structure, Tertiary , Stereoisomerism , Xenograft Model Antitumor AssaysABSTRACT
We have recently reported CDK inhibitors based on the 6-substituted pyrrolo[3,4-c]pyrazole core structure. Improvement of inhibitory potency against multiple CDKs, antiproliferative activity against cancer cell lines and optimization of the physico-chemical properties led to the identification of highly potent compounds. Compound 31 (PHA-793887) showed good efficacy in the human ovarian A2780, colon HCT-116 and pancreatic BX-PC3 carcinoma xenograft models and was well tolerated upon daily treatments by iv administration. It was identified as a drug candidate for clinical evaluation in patients with solid tumors.
Subject(s)
Antineoplastic Agents/chemistry , Cyclin-Dependent Kinases/antagonists & inhibitors , Protein Kinase Inhibitors/chemistry , Pyrazoles/chemistry , Pyrroles/chemistry , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacokinetics , Binding Sites , Cell Line, Tumor , Crystallography, X-Ray , Cyclin-Dependent Kinases/metabolism , HCT116 Cells , Humans , Injections, Intravenous , Mice , Mice, Nude , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacokinetics , Pyrazoles/chemical synthesis , Pyrazoles/pharmacokinetics , Pyrroles/chemical synthesis , Pyrroles/pharmacokinetics , Xenograft Model Antitumor AssaysABSTRACT
The histone deacetylases (HDACs) are able to regulate gene expression, and histone deacetylase inhibitors (HDACi) emerged as a new class of agents in the treatment of cancer as well as other human disorders such as neurodegenerative diseases. In the present investigation, we report on the synthesis and biological evaluation of compounds derived from the expansion of a HDAC inhibitor scaffold having N-hydroxy-3-phenyl-2-propenamide and N-hydroxy-3-(pyridin-2-yl)-2-propenamide as core structures and containing a phenyloxopropenyl moiety, either unsubstituted or substituted by a 4-methylpiperazin-1-yl or 4-methylpiperazin-1-ylmethyl group. The compounds were evaluated for their ability to inhibit nuclear HDACs, as well as for their in vitro antiproliferative activity. Moreover, their metabolic stability in microsomes and aqueous solubility were studied and selected compounds were further characterized by in vivo pharmacokinetic experiments. These compounds showed a remarkable stability in vivo, compared to hydroxamic acid HDAC inhibitors that have already entered clinical trials. The representative compound 30b showed in vivo antitumor activity in a human colon carcinoma xenograft model.
Subject(s)
Acrylamides/chemical synthesis , Antineoplastic Agents/chemical synthesis , Histone Deacetylase Inhibitors/chemical synthesis , Acrylamides/pharmacology , Antineoplastic Agents/pharmacokinetics , Benzene Derivatives , Cell Proliferation/drug effects , Colonic Neoplasms/drug therapy , Drug Stability , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacokinetics , Enzyme Inhibitors/therapeutic use , HeLa Cells , Histone Deacetylase Inhibitors/pharmacokinetics , Histone Deacetylase Inhibitors/therapeutic use , Humans , Pyridines , Structure-Activity Relationship , Xenograft Model Antitumor AssaysABSTRACT
Cdc7 kinase is an essential protein that promotes DNA replication in eukaryotic organisms. Genetic evidence indicates that Cdc7 inhibition can cause selective tumor-cell death in a p53-independent manner, supporting the rationale for developing Cdc7 small-molecule inhibitors for the treatment of cancers. In this paper, the synthesis and structure-activity relationships of 2-heteroaryl-pyrrolopyridinones, the first potent Cdc7 kinase inhibitors, are described. Starting from 2-pyridin-4-yl-1,5,6,7-tetrahydro-pyrrolo[3,2-c]pyridin-4-one, progress toward a simple scaffold, tailored for Cdc7 inhibition, is reported.
Subject(s)
Antineoplastic Agents/chemical synthesis , Cell Cycle Proteins/antagonists & inhibitors , Protein Serine-Threonine Kinases/antagonists & inhibitors , Pyridones/chemical synthesis , Pyrroles/chemical synthesis , Amino Acid Sequence , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Binding Sites , Cell Cycle Proteins/chemistry , Cell Line, Tumor , Drug Screening Assays, Antitumor , Furans/chemical synthesis , Furans/chemistry , Furans/pharmacology , Humans , Models, Molecular , Molecular Sequence Data , Protein Binding , Protein Serine-Threonine Kinases/chemistry , Pyridones/chemistry , Pyridones/pharmacology , Pyrroles/chemistry , Pyrroles/pharmacology , Sequence Homology, Amino Acid , Structure-Activity RelationshipABSTRACT
We have recently reported a new class of CDK2/cyclin A inhibitors based on a bicyclic tetrahydropyrrolo[3,4-c]pyrazole scaffold. The introduction of small alkyl or cycloalkyl groups in position 6 of this scaffold allowed variation at the other two diversity points. Conventional and polymer-assisted solution phase chemistry provided a way of generating compounds with improved biochemical and cellular activity. Optimization of the physical properties and pharmacokinetic profile led to a compound which exhibited good efficacy in vivo on A2780 human ovarian carcinoma.
Subject(s)
Cyclin-Dependent Kinase 2/antagonists & inhibitors , Drug Design , Protein Kinase Inhibitors/classification , Protein Kinase Inhibitors/chemical synthesis , Pyrazoles/chemistry , Pyrroles/chemistry , Animals , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/classification , Antineoplastic Agents/metabolism , Bridged Bicyclo Compounds, Heterocyclic/administration & dosage , Bridged Bicyclo Compounds, Heterocyclic/chemical synthesis , Bridged Bicyclo Compounds, Heterocyclic/chemistry , Bridged Bicyclo Compounds, Heterocyclic/metabolism , Caco-2 Cells , Cell Line, Tumor , Cell Proliferation/drug effects , Cyclin-Dependent Kinase 2/metabolism , Growth Inhibitors/administration & dosage , Growth Inhibitors/chemical synthesis , Growth Inhibitors/classification , Growth Inhibitors/metabolism , Humans , Isoenzymes/antagonists & inhibitors , Isoenzymes/metabolism , Mice , Mice, Nude , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/metabolismABSTRACT
We have recently reported about a new class of Aurora-A inhibitors based on a bicyclic tetrahydropyrrolo[3,4-c]pyrazole scaffold. Here we describe the synthesis and early expansion of CDK2/cyclin A-E inhibitors belonging to the same chemical class. Synthesis of the compounds was accomplished using a solution-phase protocol amenable to rapid parallel expansion. Compounds with nanomolar activity in the biochemical assay and able to efficiently inhibit CDK2-mediated tumor cell proliferation have been obtained.
Subject(s)
Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Cyclin-Dependent Kinase 2/antagonists & inhibitors , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Pyrazoles/pharmacology , Antineoplastic Agents/classification , Aurora Kinases , Cell Line, Tumor , Cell Proliferation/drug effects , Crystallography, X-Ray , Cyclin A/antagonists & inhibitors , Drug Screening Assays, Antitumor , Enzyme Inhibitors/classification , Humans , Models, Molecular , Molecular Structure , Protein Serine-Threonine Kinases/antagonists & inhibitors , Pyrazoles/chemical synthesis , Structure-Activity RelationshipABSTRACT
N-(5-Bromo-1,3-thiazol-2-yl)butanamide (compound 1) was found active (IC50=808 nM) in a high throughput screening (HTS) for CDK2 inhibitors. By exploiting crystal structures of several complexes between CDK2 and inhibitors and applying structure-based drug design (SBDD), we rapidly discovered a very potent and selective CDK2 inhibitor 4-[(5-isopropyl-1,3-thiazol-2-yl)amino] benzenesulfonamide (compound 4, IC50=20 nM). The syntheses, structure-based analog design, kinases inhibition data and X-ray crystallographic structures of CDK2/inhibitor complexes are reported.
Subject(s)
Cyclin-Dependent Kinase 2/antagonists & inhibitors , Cyclin-Dependent Kinase 2/chemistry , Drug Design , Amino Acid Sequence , Binding Sites , Crystallography, X-Ray , Entropy , Humans , Hydrophobic and Hydrophilic Interactions , Inhibitory Concentration 50 , Models, Molecular , Molecular Sequence Data , Protein Binding , Protein Conformation , Sequence Homology, Amino Acid , Structure-Activity Relationship , X-Ray DiffractionABSTRACT
Abnormal proliferation mediated by disruption of the normal cell cycle mechanisms is a hallmark of virtually all cancer cells. Compounds targeting complexes between cyclin-dependent kinases (CDK) and cyclins, such as CDK2/cyclin A and CDK2/cyclin E, and inhibiting their kinase activity are regarded as promising antitumor agents to complement the existing therapies. From a high-throughput screening effort, we identified a new class of CDK2/cyclin A/E inhibitors. The hit-to-lead expansion of this class is described. X-ray crystallographic data of early compounds in this series, as well as in vitro testing funneled for rapidly achieving in vivo efficacy, led to a nanomolar inhibitor of CDK2/cyclin A (N-(5-cyclopropyl-1H-pyrazol-3-yl)-2-(2-naphthyl)acetamide (41), PNU-292137, IC50 = 37 nM) with in vivo antitumor activity (TGI > 50%) in a mouse xenograft model at a dose devoid of toxic effects.
