RESUMO
Cyclin-dependent kinases (CDKs) are key regulators of the cell cycle and are frequently altered in cancer cells, thereby leading to uncontrolled proliferation. In this context, CDK2 has emerged as an appealing target for anticancer drug development. Herein, we describe the discovery of a series of selective small molecule inhibitors of CDK2 beginning with historical compounds from our ERK2 program (e.g., compound 6). Structure-based drug design led to the potent and selective tool compound 32, where excellent selectivity against ERK2 and CDK4 was achieved by filling the lipophilic DFG-1 pocket and targeting interactions with CDK2-specific lower hinge binding residues, respectively. Compound 32 demonstrated 112% tumor growth inhibition in mice bearing OVCAR3 tumors with 50 mg/kg bis in die (BID) oral dosing.
RESUMO
Bromodomains are acetyllysine recognition domains present in a variety of human proteins. Bromodomains also bind small molecules that compete with acetyllysine, and therefore bromodomains have been targets for drug discovery efforts. Highly potent and selective ligands with good cellular permeability have been proposed as chemical probes for use in exploring the functions of many of the bromodomain proteins. We report here the discovery of a class of such inhibitors targeting the family VIII bromodomains of SMARCA2 (BRM) and SMARCA4 (BRG1), and PBRM1 (polybromo-1) bromodomain 5. We propose one example from this series, GNE-064, as a chemical probe for the bromodomains SMARCA2, SMARCA4, and PBRM1(5) with the potential for in vivo use.
Assuntos
DNA Helicases , Fatores de Transcrição , Proteínas de Ligação a DNA , Humanos , Proteínas Nucleares , Domínios ProteicosRESUMO
Transient receptor potential ankyrin 1 (TRPA1) antagonists have generated broad interest in the pharmaceutical industry for the treatment of both pain and asthma. Over the past decade, multiple antagonist classes have been reported in the literature with a wide range of structural diversity. Our own work has focused on the development of proline sulfonamide and hypoxanthine-based antagonists, two antagonist classes with distinct physicochemical properties and pharmacokinetic (PK) trends. Late in our discovery program, cryogenic electron microscopy (cryoEM) studies revealed two different antagonist binding sites: a membrane-exposed proline sulfonamide transmembrane site and an intracellular hypoxanthine site near the membrane interface. A retrospective look at the discovery program reveals how the different binding sites, and their location relative to the cell membrane, influenced the optimization trajectories and overall drug profiles of each antagonist class.
RESUMO
Transient receptor potential ankyrin 1 (TRPA1) is a nonselective calcium-permeable ion channel highly expressed in the primary sensory neurons functioning as a polymodal sensor for exogenous and endogenous stimuli and has generated widespread interest as a target for inhibition due to its implication in neuropathic pain and respiratory disease. Herein, we describe the optimization of a series of potent, selective, and orally bioavailable TRPA1 small molecule antagonists, leading to the discovery of a novel tetrahydrofuran-based linker. Given the balance of physicochemical properties and strong in vivo target engagement in a rat AITC-induced pain assay, compound 20 was progressed into a guinea pig ovalbumin asthma model where it exhibited significant dose-dependent reduction of inflammatory response. Furthermore, the structure of the TRPA1 channel bound to compound 21 was determined via cryogenic electron microscopy to a resolution of 3 Å, revealing the binding site and mechanism of action for this class of antagonists.
Assuntos
Asma/tratamento farmacológico , Furanos/uso terapêutico , Purinas/uso terapêutico , Canal de Cátion TRPA1/antagonistas & inibidores , Animais , Asma/induzido quimicamente , Asma/complicações , Células CHO , Cricetulus , Furanos/síntese química , Furanos/metabolismo , Cobaias , Humanos , Inflamação/tratamento farmacológico , Inflamação/etiologia , Ligantes , Masculino , Estrutura Molecular , Ovalbumina , Oxidiazóis/síntese química , Oxidiazóis/metabolismo , Oxidiazóis/uso terapêutico , Ligação Proteica , Purinas/síntese química , Purinas/metabolismo , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Canal de Cátion TRPA1/metabolismoRESUMO
Cyclic adenosine monophosphate-response element (CREB)-binding protein (CBP) and EP300E1A-binding protein (p300) are members of the bromodomain and extraterminal motif (BET) family. These highly homologous proteins have a key role in modulating transcription, including altering the status of chromatin or through interactions with or posttranslational modifications of transcription factors. As CBP and p300 have known roles for stimulating c-Myc oncogenic activity, a small-molecule inhibitor, GNE-781, was developed to selectively and potently inhibit the CBP/p300 bromodomains (BRDs). Genetic models have been challenging to develop due to embryonic lethality arising from germline homozygous mutations in either CBP or P300. Hence, the purpose of this study was to characterize the role of dual inhibition of these proteins in adult rats and dogs. Repeat dose toxicity studies were conducted, and toxicologic and pathologic end points were assessed. GNE-781 was generally tolerated; however, marked effects on thrombopoiesis occurred in both species. Evidence of inhibition of erythroid, granulocytic, and lymphoid cell differentiation was also present, as well as deleterious changes in gastrointestinal and reproductive tissues. These findings are consistent with many preclinical (and clinical) effects reported with BET inhibitors targeting BRD proteins; thus, the current study findings indicate a likely important role for CBP/p300 in stem cell differentiation.
Assuntos
Pirazóis/farmacologia , Piridinas/farmacologia , Fatores de Transcrição de p300-CBP/antagonistas & inibidores , Animais , Cães , Avaliação Pré-Clínica de Medicamentos/métodos , Canais de Potássio Éter-A-Go-Go/efeitos dos fármacos , Feminino , Humanos , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
The transient receptor potential ankyrin 1 (TRPA1) channel functions as an irritant sensor and is a therapeutic target for treating pain, itch, and respiratory diseases. As a ligand-gated channel, TRPA1 can be activated by electrophilic compounds such as allyl isothiocyanate (AITC) through covalent modification or activated by noncovalent agonists through ligand binding. However, how covalent modification leads to channel opening and, importantly, how noncovalent binding activates TRPA1 are not well-understood. Here we report a class of piperidine carboxamides (PIPCs) as potent, noncovalent agonists of human TRPA1. Based on their species-specific effects on human and rat channels, we identified residues critical for channel activation; we then generated binding modes for TRPA1-PIPC interactions using structural modeling, molecular docking, and mutational analysis. We show that PIPCs bind to a hydrophobic site located at the interface of the pore helix 1 (PH1) and S5 and S6 transmembrane segments. Interestingly, this binding site overlaps with that of known allosteric modulators, such as A-967079 and propofol. Similar binding sites, involving π-helix rearrangements on S6, have been recently reported for other TRP channels, suggesting an evolutionarily conserved mechanism. Finally, we show that for PIPC analogs, predictions from computational modeling are consistent with experimental structure-activity studies, thereby suggesting strategies for rational drug design.
Assuntos
Simulação de Acoplamento Molecular , Piperidinas/farmacologia , Canal de Cátion TRPA1/química , Canal de Cátion TRPA1/efeitos dos fármacos , Animais , Sítios de Ligação , Canais de Cálcio/química , Canais de Cálcio/metabolismo , Desenho de Fármacos , Humanos , Isotiocianatos , Ligantes , Modelos Estruturais , Mutagênese , Oximas/farmacologia , Propofol/farmacologia , Domínios Proteicos , Ratos , Especificidade da Espécie , Canal de Cátion TRPA1/metabolismoRESUMO
Regulatory T cells (Treg) are immunosuppressive and negatively impact response to cancer immunotherapies. CREB-binding protein (CBP) and p300 are closely related acetyltransferases and transcriptional coactivators. Here, we evaluate the mechanisms by which CBP/p300 regulate Treg differentiation and the consequences of CBP/p300 loss-of-function mutations in follicular lymphoma. Transcriptional and epigenetic profiling identified a cascade of transcription factors essential for Treg differentiation. Mass spectrometry analysis showed that CBP/p300 acetylates prostacyclin synthase, which regulates Treg differentiation by altering proinflammatory cytokine secretion by T and B cells. Reduced Treg presence in tissues harboring CBP/p300 loss-of-function mutations was observed in follicular lymphoma. Our findings provide novel insights into the regulation of Treg differentiation by CBP/p300, with potential clinical implications on alteration of the immune landscape. SIGNIFICANCE: This study provides insights into the dynamic role of CBP/p300 in the differentiation of Tregs, with potential clinical implications in the alteration of the immune landscape in follicular lymphoma.
Assuntos
Proteína de Ligação a CREB/imunologia , Proteína p300 Associada a E1A/imunologia , Linfoma Folicular/imunologia , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/imunologia , Acetilação , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Proteína de Ligação a CREB/antagonistas & inibidores , Proteína de Ligação a CREB/genética , Diferenciação Celular/fisiologia , Regulação para Baixo , Proteína p300 Associada a E1A/antagonistas & inibidores , Proteína p300 Associada a E1A/genética , Histonas/metabolismo , Humanos , Linfoma Folicular/genética , Linfoma Folicular/metabolismo , Linfoma Folicular/patologia , Mutação , Pirazóis/farmacologia , Piridinas/farmacologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/metabolismo , Transcrição Gênica , TranscriptomaRESUMO
Myeloid-derived suppressor cells (MDSCs) are found in most cancer malignancies and support tumorigenesis by suppressing immunity and promoting tumor growth. Here we identify the bromodomain (BRD) of CBP/EP300 as a critical regulator of H3K27 acetylation (H3K27ac) in MDSCs across promoters and enhancers of pro-tumorigenic target genes. In preclinical tumor models, in vivo administration of a CBP/EP300-BRD inhibitor (CBP/EP300-BRDi) alters intratumoral MDSCs and attenuates established tumor growth in immunocompetent tumor-bearing mice, as well as in MDSC-dependent xenograft models. Inhibition of CBP/EP300-BRD redirects tumor-associated MDSCs from a suppressive to an inflammatory phenotype through downregulation of STAT pathway-related genes and inhibition of Arg1 and iNOS. Similarly, CBP/EP300-BRDi decreases differentiation and suppressive function of human MDSCs in vitro. Our findings uncover a role of CBP/EP300-BRD in intratumoral MDSCs that may be targeted therapeutically to boost anti-tumor immunity.
Assuntos
Carcinogênese/metabolismo , Histonas/metabolismo , Células Mieloides/metabolismo , Fatores de Transcrição de p300-CBP/metabolismo , Acetilação , Animais , Arginase/genética , Arginase/metabolismo , Linhagem Celular Tumoral , Células Cultivadas , Elementos Facilitadores Genéticos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos SCID , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Regiões Promotoras Genéticas , Domínios Proteicos , Fatores de Transcrição STAT/metabolismo , Fatores de Transcrição de p300-CBP/químicaRESUMO
The biological functions of the dual bromodomains of human transcription-initiation-factor TFIID subunit 1 (TAF1(1,2)) remain unknown, although TAF1 has been identified as a potential target for oncology research. Here, we describe the discovery of a potent and selective in vitro tool compound for TAF1(2), starting from a previously reported lead. A cocrystal structure of lead compound 2 bound to TAF1(2) enabled structure-based design and structure-activity-relationship studies that ultimately led to our in vitro tool compound, 27 (GNE-371). Compound 27 binds TAF1(2) with an IC50 of 10 nM while maintaining excellent selectivity over other bromodomain-family members. Compound 27 is also active in a cellular-TAF1(2) target-engagement assay (IC50 = 38 nM) and exhibits antiproliferative synergy with the BET inhibitor JQ1, suggesting engagement of endogenous TAF1 by 27 and further supporting the use of 27 in mechanistic and target-validation studies.
Assuntos
Benzimidazóis/metabolismo , Desenho de Fármacos , Sondas Moleculares/metabolismo , Fator de Transcrição TFIID/química , Fator de Transcrição TFIID/metabolismo , Humanos , Modelos Moleculares , Conformação Proteica , Domínios ProteicosRESUMO
Acetylation of histone H3 at lysine 27 is a well-defined marker of enhancer activity. However, the functional impact of this modification at enhancers is poorly understood. Here, we use a chemical genetics approach to acutely block the function of the cAMP response element binding protein (CREB) binding protein (CBP)/P300 bromodomain in models of hematological malignancies and describe a consequent loss of H3K27Ac specifically from enhancers, despite the continued presence of CBP/P300 at chromatin. Using this approach to dissect the role of H3K27Ac at enhancers, we identify a critical role for this modification in the production of enhancer RNAs and transcription of enhancer-regulated gene networks.
Assuntos
Elementos Facilitadores Genéticos , Histonas/metabolismo , Processamento de Proteína Pós-Traducional , RNA Neoplásico/genética , Fatores de Transcrição de p300-CBP/genética , Acetilação , Sítios de Ligação , Linhagem Celular Tumoral , Cromatina/química , Cromatina/metabolismo , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/metabolismo , Histonas/genética , Humanos , Lisina/metabolismo , Ligação Proteica , Domínios Proteicos , RNA Neoplásico/metabolismo , Transcrição Gênica , Fatores de Transcrição de p300-CBP/metabolismoRESUMO
A novel, potent, and orally bioavailable inhibitor of the bromodomain of CBP, compound 35 (GNE-207), has been identified through SAR investigations focused on optimizing al bicyclic heteroarene to replace the aniline present in the published GNE-272 series. Compound 35â¯has excellent CBP potency (CBP IC50â¯=â¯1â¯nM, MYC EC50â¯=â¯18â¯nM), a selectively index ofâ¯>2500-fold against BRD4(1), and exhibits a good pharmacokinetic profile.
Assuntos
Compostos de Bifenilo/química , Desenho de Fármacos , Fatores de Transcrição de p300-CBP/antagonistas & inibidores , Animais , Sítios de Ligação , Compostos de Bifenilo/síntese química , Compostos de Bifenilo/metabolismo , Proteínas de Ciclo Celular , Cristalografia por Raios X , Meia-Vida , Humanos , Ligação de Hidrogênio , Concentração Inibidora 50 , Camundongos , Microssomos Hepáticos/metabolismo , Simulação de Dinâmica Molecular , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/metabolismo , Estrutura Terciária de Proteína , Ratos , Relação Estrutura-Atividade , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/metabolismo , Fatores de Transcrição de p300-CBP/metabolismoRESUMO
The epigenetic regulator CBP/P300 presents a novel therapeutic target for oncology. Previously, we disclosed the development of potent and selective CBP bromodomain inhibitors by first identifying pharmacophores that bind the KAc region and then building into the LPF shelf. Herein, we report the "hybridization" of a variety of KAc-binding fragments with a tetrahydroquinoline scaffold that makes optimal interactions with the LPF shelf, imparting enhanced potency and selectivity to the hybridized ligand. To demonstrate the utility of our hybridization approach, two analogues containing unique Asn binders and the optimized tetrahydroquinoline moiety were rapidly optimized to yield single-digit nanomolar inhibitors of CBP with exquisite selectivity over BRD4(1) and the broader bromodomain family.
Assuntos
Ensaios de Triagem em Larga Escala/métodos , Fatores de Transcrição de p300-CBP/antagonistas & inibidores , Animais , Asparagina/química , Asparagina/metabolismo , Sítios de Ligação , Proteínas de Ciclo Celular , Cristalografia por Raios X , Feminino , Transferência Ressonante de Energia de Fluorescência/métodos , Camundongos Endogâmicos , Simulação de Acoplamento Molecular , Proteínas Nucleares/antagonistas & inibidores , Domínios Proteicos , Pirazóis/química , Piridinas/química , Quinolinas/química , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição de p300-CBP/química , Fatores de Transcrição de p300-CBP/metabolismoRESUMO
Inhibition of the bromodomain of the transcriptional regulator CBP/P300 is an especially interesting new therapeutic approach in oncology. We recently disclosed in vivo chemical tool 1 (GNE-272) for the bromodomain of CBP that was moderately potent and selective over BRD4(1). In pursuit of a more potent and selective CBP inhibitor, we used structure-based design. Constraining the aniline of 1 into a tetrahydroquinoline motif maintained potency and increased selectivity 2-fold. Structure-activity relationship studies coupled with further structure-based design targeting the LPF shelf, BC loop, and KAc regions allowed us to significantly increase potency and selectivity, resulting in the identification of non-CNS penetrant 19 (GNE-781, TR-FRET IC50 = 0.94 nM, BRET IC50 = 6.2 nM; BRD4(1) IC50 = 5100 nΜ) that maintained good in vivo PK properties in multiple species. Compound 19 displays antitumor activity in an AML tumor model and was also shown to decrease Foxp3 transcript levels in a dose dependent manner.
Assuntos
Antineoplásicos/farmacologia , Proteína de Ligação a CREB/antagonistas & inibidores , Pirazóis/farmacologia , Piridinas/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacocinética , Proteína de Ligação a CREB/química , Cães , Feminino , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Células HEK293 , Humanos , Macaca fascicularis , Masculino , Camundongos , Domínios Proteicos , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Pirazóis/síntese química , Pirazóis/química , Pirazóis/farmacocinética , Piridinas/síntese química , Piridinas/química , Piridinas/farmacocinética , RNA/genética , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Herein we report identification of an imidazopyridine class of potent and selective TYK2 inhibitors, exemplified by prototype 6, through constraint of the rotatable amide bond connecting the pyridine and aryl rings of compound 1. Further optimization led to generation of compound 30 that potently inhibits the TYK2 enzyme and the IL-23 pathway in cells, exhibits selectivity against cellular JAK2 activity, and has good pharmacokinetic properties. In mice, compound 30 demonstrated dose-dependent reduction of IL-17 production in a PK/PD model as well as in an imiquimod-induced psoriasis model. In this efficacy model, the IL-17 decrease was accompanied by a reduction of ear thickness indicating the potential of TYK2 inhibition as a therapeutic approach for psoriasis patients.
Assuntos
Imidazóis/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Piridinas/farmacologia , TYK2 Quinase/antagonistas & inibidores , Relação Dose-Resposta a Droga , Humanos , Imidazóis/síntese química , Imidazóis/química , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Piridinas/síntese química , Piridinas/química , Relação Estrutura-Atividade , TYK2 Quinase/metabolismoRESUMO
Resistance invariably develops to antiandrogen therapies used to treat newly diagnosed prostate cancers, but effective treatments for castration-resistant disease remain elusive. Here, we report that the transcriptional coactivator CBP/p300 is required to maintain the growth of castration-resistant prostate cancer. To exploit this vulnerability, we developed a novel small-molecule inhibitor of the CBP/p300 bromodomain that blocks prostate cancer growth in vitro and in vivo Molecular dissection of the consequences of drug treatment revealed a critical role for CBP/p300 in histone acetylation required for the transcriptional activity of the androgen receptor and its target gene expression. Our findings offer a preclinical proof of concept for small-molecule therapies to target the CBP/p300 bromodomain as a strategy to treat castration-resistant prostate cancer. Cancer Res; 77(20); 5564-75. ©2017 AACR.
Assuntos
Proteína p300 Associada a E1A/antagonistas & inibidores , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proteína p300 Associada a E1A/deficiência , Proteína p300 Associada a E1A/genética , Proteína p300 Associada a E1A/metabolismo , Feminino , Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Masculino , Camundongos , Camundongos SCID , Terapia de Alvo Molecular , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/metabolismo , Neoplasias de Próstata Resistentes à Castração/patologia , Domínios Proteicos , Distribuição Aleatória , Receptores Androgênicos/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transfecção , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The biological function of bromodomains, epigenetic readers of acetylated lysine residues, remains largely unknown. Herein we report our efforts to discover a potent and selective inhibitor of the bromodomain of cat eye syndrome chromosome region candidate 2 (CECR2). Screening of our internal medicinal chemistry collection led to the identification of a pyrrolopyridone chemical lead, and subsequent structure-based drug design led to a potent and selective CECR2 bromodomain inhibitor (GNE-886) suitable for use as an in vitro tool compound.
RESUMO
Bromodomain-containing protein 9 (BRD9), an epigenetic "reader" of acetylated lysines on post-translationally modified histone proteins, is upregulated in multiple cancer cell lines. To assess the functional role of BRD9 in cancer cell lines, we identified a small-molecule inhibitor of the BRD9 bromodomain. Starting from a pyrrolopyridone lead, we used structure-based drug design to identify a potent and highly selective in vitro tool compound 11, (GNE-375). While this compound showed minimal effects in cell viability or gene expression assays, it showed remarkable potency in preventing the emergence of a drug tolerant population in EGFR mutant PC9 cells treated with EGFR inhibitors. Such tolerance has been linked to an altered epigenetic state, and 11 decreased BRD9 binding to chromatin, and this was associated with decreased expression of ALDH1A1, a gene previously shown to be important in drug tolerance. BRD9 inhibitors may therefore show utility in preventing epigenetically-defined drug resistance.
Assuntos
Resistência a Medicamentos/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Fatores de Transcrição/antagonistas & inibidores , Aldeído Desidrogenase/genética , Família Aldeído Desidrogenase 1 , Linhagem Celular Tumoral , Desenho de Fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos , Simulação de Acoplamento Molecular , Piridonas/química , Piridonas/farmacologia , Retinal Desidrogenase , Fatores de Transcrição/metabolismoRESUMO
The single bromodomain of the closely related transcriptional regulators CBP/EP300 is a target of much recent interest in cancer and immune system regulation. A co-crystal structure of a ligand-efficient screening hit and the CBP bromodomain guided initial design targeting the LPF shelf, ZA loop, and acetylated lysine binding regions. Structure-activity relationship studies allowed us to identify a more potent analogue. Optimization of permeability and microsomal stability and subsequent improvement of mouse hepatocyte stability afforded 59 (GNE-272, TR-FRET IC50 = 0.02 µM, BRET IC50 = 0.41 µM, BRD4(1) IC50 = 13 µM) that retained the best balance of cell potency, selectivity, and in vivo PK. Compound 59 showed a marked antiproliferative effect in hematologic cancer cell lines and modulates MYC expression in vivo that corresponds with antitumor activity in an AML tumor model.
Assuntos
Antineoplásicos/farmacologia , Descoberta de Drogas , Pirazóis/farmacologia , Piridonas/farmacologia , Fatores de Transcrição de p300-CBP/antagonistas & inibidores , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cães , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Células Madin Darby de Rim Canino , Camundongos , Camundongos Nus , Modelos Moleculares , Estrutura Molecular , Pirazóis/síntese química , Pirazóis/química , Piridonas/síntese química , Piridonas/química , Relação Estrutura-AtividadeRESUMO
The biological role played by non-BET bromodomains remains poorly understood, and it is therefore imperative to identify potent and highly selective inhibitors to effectively explore the biology of individual bromodomain proteins. A ligand-efficient nonselective bromodomain inhibitor was identified from a 6-methyl pyrrolopyridone fragment. Small hydrophobic substituents replacing the N-methyl group were designed directing toward the conserved bromodomain water pocket, and two distinct binding conformations were then observed. The substituents either directly displaced and rearranged the conserved solvent network, as in BRD4(1) and TAF1(2), or induced a narrow hydrophobic channel adjacent to the lipophilic shelf, as in BRD9 and CECR2. The preference of distinct substituents for individual bromodomains provided selectivity handles useful for future lead optimization efforts for selective BRD9, CECR2, and TAF1(2) inhibitors.
Assuntos
Histona Acetiltransferases/antagonistas & inibidores , Proteínas Nucleares/antagonistas & inibidores , Piridonas/farmacologia , Pirróis/farmacologia , Fatores Associados à Proteína de Ligação a TATA/antagonistas & inibidores , Fator de Transcrição TFIID/antagonistas & inibidores , Fatores de Transcrição/antagonistas & inibidores , Água/química , Sítios de Ligação/efeitos dos fármacos , Proteínas de Ciclo Celular , Relação Dose-Resposta a Droga , Transferência Ressonante de Energia de Fluorescência , Fluorometria , Histona Acetiltransferases/metabolismo , Humanos , Ligantes , Modelos Moleculares , Conformação Molecular , Proteínas Nucleares/metabolismo , Piridonas/síntese química , Piridonas/química , Pirróis/síntese química , Pirróis/química , Relação Estrutura-Atividade , Fatores Associados à Proteína de Ligação a TATA/metabolismo , Fator de Transcrição TFIID/metabolismo , Fatores de Transcrição/metabolismoRESUMO
CBP and EP300 are highly homologous, bromodomain-containing transcription coactivators involved in numerous cellular pathways relevant to oncology. As part of our effort to explore the potential therapeutic implications of selectively targeting bromodomains, we set out to identify a CBP/EP300 bromodomain inhibitor that was potent both in vitro and in cellular target engagement assays and was selective over the other members of the bromodomain family. Reported here is a series of cell-potent and selective probes of the CBP/EP300 bromodomains, derived from the fragment screening hit 4-methyl-1,3,4,5-tetrahydro-2H-benzo[b][1,4]diazepin-2-one.