RESUMO
Janus kinases (JAKs) play a critical role in modulating the function and expression of inflammatory cytokines related to rheumatoid arthritis (RA). Herein, we report the design, synthesis, and structure-activity relationships (SARs) of a series of novel quinazoline derivatives as JAK inhibitors. Among these inhibitors, compound 11n showed high potency against JAKs (JAK1/JAK2/JAK3/TYK2, IC50 = 0.40, 0.83, 2.10, 1.95 nM), desirable metabolic characters, and excellent pharmacokinetic properties. In collagen-induced arthritis (CIA) models, compound 11n exhibited significant reduction in joint swelling with good safety, which could be served as a potential therapeutic candidate for the treatment of inflammatory diseases.
Assuntos
Artrite Reumatoide , Inibidores de Janus Quinases , Humanos , Inibidores de Janus Quinases/farmacologia , Inibidores de Janus Quinases/uso terapêutico , Quinazolinas/farmacologia , Quinazolinas/uso terapêutico , Janus Quinases , Relação Estrutura-Atividade , Artrite Reumatoide/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêuticoRESUMO
The receptor tyrosine kinase AXL is an emerging driver of cancer recurrence, while its molecular mechanism remains unclear. In this study we investigated how AXL regulated the disease progression and poor prognosis in non-small cell lung cancer (NSCLC) and triple negative breast cancer (TNBC). We performed AXL transcriptome analysis from TCGA datasets, and found that AXL expression was significantly elevated in NSCLC and TNBC correlating with poor prognosis, epithelial-mesenchymal transition (EMT) and immune-tolerant tumor microenvironment (TME). Knockdown of AXL or treatment with two independent AXL antibodies (named anti-AXL and AXL02) all diminished cell migration and EMT in AXL-high expressing NSCLC and TNBC cell lines. In a mouse model of 4T1 TNBC, administration of anti-AXL antibody substantially inhibited lung metastases formation and growth, accompanied by reduced downstream signaling activation, EMT and proliferation index, as well as an increased apoptosis and activated anti-tumor immunity. We found that AXL was abundantly activated in tumor nodule-infiltrated M2-macrophages. A specific anti-AXL antibody blocked bone marrow-derived macrophage (BMDM) M2-polarization in vitro. Targeting of AXL in M2-macrophage in addition to tumor cell substantially suppressed CSF-1 production and eliminated M2-macrophage in TME, leading to a coordinated enhancement in both the innate and adaptive immunity reflecting M1-like macrophages, mature dendritic cells, cytotoxic T cells and B cells. We generated a novel and humanized AXL-ADC (AXL02-MMAE) employing a site-specific conjugation platform. AXL02-MMAE exerted potent cytotoxicity against a panel of AXL-high expressing tumor cell lines (IC50 < 0.1 nmol/L) and suppressed in vivo growth of multiple NSCLC and glioma tumors (a minimum efficacy dose<1 mg/kg). Compared to chemotherapy, AXL02-MMAE achieved a superior efficacy in regressing large sized tumors, eliminated AXL-H tumor cell-dependent M2-macrophage infiltration with a robust accumulation of inflammatory macrophages and mature dendritic cells. Our results support AXL-targeted therapy for treatment of advanced NSCLC and TNBC.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Neoplasias de Mama Triplo Negativas , Humanos , Animais , Camundongos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/patologia , Proliferação de Células , Transição Epitelial-Mesenquimal , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia , Linhagem Celular Tumoral , Anticorpos/metabolismo , Macrófagos/metabolismo , Microambiente TumoralRESUMO
Oestrogen related receptor α participated in the regulation of oxidative metabolism and mitochondrial biogenesis, and was overexpressed in many cancers including triple-negative breast cancer. A set of new ERRα inverse agonists based on p-nitrobenzenesulfonamide template were discovered and compound 11 with high potent activity (IC50 = 0.80 µM) could significantly inhibit the transcription of ERRα-regulated target genes. By regulating the downstream signalling pathway, compound 11 could suppress the migration and invasion of the ER-negative MDA-MB-231 cell line. Furthermore, compound 11 demonstrated a significant growth suppression of breast cancer xenograft tumours in vivo (inhibition rate 23.58%). The docking results showed that compound 11 could form hydrogen bonds with Glu331 and Arg372 in addition to its hydrophobic interaction with ligand-binding domain. Our data implied that compound 11 represented a novel and effective ERRα inverse agonist, which had broad application prospects in the treatment of triple-negative breast cancer.
Assuntos
Antineoplásicos/farmacologia , Descoberta de Drogas , Nitrobenzenos/farmacologia , Receptores de Estrogênio/metabolismo , Sulfonamidas/farmacologia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Nitrobenzenos/síntese química , Nitrobenzenos/química , Relação Estrutura-Atividade , Sulfonamidas/síntese química , Sulfonamidas/química , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Receptor ERRalfa Relacionado ao EstrogênioRESUMO
The Bromodomain and Extra-terminal domain (BET) proteins are promising targets in treating cancers. Although BET inhibitors have been in clinical trials, they are limited by lacking of suitable biomarkers to indicate drug responses in different cancers. Here we identify DHRS2, ETV4 and NOTUM as potential biomarkers to indicate drug resistance in liver cancer cells of a recently discovered BET inhibitor, Hjp-6-171. Furthermore, we confirm that reactivation of WNT pathway, the target of NOTUM, contributes to the drug sensitivity restoration in Hjp-6-171 resistant cells. Specially, combinations of Hjp-6-171 and a GSK3ß inhibitor CHIR-98014 show remarkable therapeutic effects in vitro and in vivo. Integrating RNA-seq and ChIP-seq data, we reveal the expression signature of ß-catenin regulated genes is contrary in sensitive cells to that in resistant cells. We propose WNT signaling molecules such as ß-catenin and ETV4 to be candidate biomarkers to indicate BET inhibitor responses in liver cancer patients.
Assuntos
Neoplasias Hepáticas , Via de Sinalização Wnt , Carbonil Redutase (NADPH)/genética , Carbonil Redutase (NADPH)/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Via de Sinalização Wnt/genética , beta Catenina/genética , beta Catenina/metabolismoRESUMO
G-quadruplexes (G4s) are DNA or RNA structures formed by guanine-rich repeating sequences. Recently, G4s have become a highly attractive therapeutic target for BRCA-deficient cancers. Here, we show that a substituted quinolone amide compound, MTR-106, stabilizes DNA G-quadruplexes in vitro. MTR-106 displayed significant antiproliferative activity in homologous recombination repair (HR)-deficient and PARP inhibitor (PARPi)-resistant cancer cells. Moreover, MTR-106 increased DNA damage and promoted cell cycle arrest and apoptosis to inhibit cell growth. Importantly, its oral and i.v. administration significantly impaired tumor growth in BRCA-deficient xenograft mouse models. However, MTR-106 showed modest activity against talazoparib-resistant xenograft models. In rats, the drug rapidly distributes to tissues within 5 min, and its average concentrations were 12-fold higher in the tissues than in the plasma. Overall, we identified MTR-106 as a novel G-quadruplex stabilizer with high tissue distribution, and it may serve as a potential anticancer agent.
Assuntos
Antineoplásicos/farmacologia , Proteína BRCA1/biossíntese , Proteína BRCA2/biossíntese , Quadruplex G/efeitos dos fármacos , Animais , Antineoplásicos/farmacocinética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/fisiologia , Humanos , Masculino , Camundongos , Camundongos Nus , Neoplasias/patologia , Ftalazinas/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Ratos , Ratos Sprague-Dawley , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Estrogen-related receptor α (ERRα), which is overexpressed in a variety of cancers has been considered as an effective target for anticancer therapy. ERRα inverse agonists have been proven to effectively inhibit the migration and invasion of cancer cells. As few crystalline complexes have been reported, molecular dynamics (MD) simulations were carried out in this study to deepen the understanding of the interaction mechanism between inverse agonists and ERRα. The binding free energy was analyzed by the MM-GBSA method. The results show that the total binding free energy was positively correlated with the biological activity of an inverse agonist. The interaction of the inverse agonist with the hydrophobic interlayer composed of Phe328 and Phe495 had an important impact on the biological activity of inverse agonists, which was confirmed by the decomposition of energy on residues. As Glu331 flipped and formed a hydrogen bond with Arg372 in the MD simulation process, the formation of hydrogen bond interaction with Glu331 was not a necessary condition for the compound to act as an inverse agonist. These rules provide guidance for the design of new inverse agonists.
Assuntos
Agonismo Inverso de Drogas , Receptores de Estrogênio/antagonistas & inibidores , Simulação de Dinâmica Molecular , Receptor ERRalfa Relacionado ao EstrogênioRESUMO
WD40 is a ubiquitous domain presented in at least 361 human proteins and acts as scaffold to form protein complexes. Among them, WDR5 protein is an important mediator in several protein complexes to exert its functions in histone modification and chromatin remodeling. Therefore, it was considered as a promising epigenetic target involving in anti-cancer drug development. In view of the protein-protein interaction nature of WDR5, we initialized a campaign to discover new peptide-mimic inhibitors of WDR5. In current study, we utilized the phage display technique and screened with a disulfide-based cyclic peptide phage library. Five rounds of biopanning were performed and isolated clones were sequenced. By analyzing the sequences, total five peptides were synthesized for binding assay. The four peptides are shown to have the moderate binding affinity. Finally, the detailed binding interactions were revealed by solving a WDR5-peptide cocrystal structure.
Assuntos
Descoberta de Drogas , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Biblioteca de Peptídeos , Peptídeos Cíclicos/farmacologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Ligantes , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/química , Ligação ProteicaRESUMO
The bromodomain and extra-terminal domain (BET) family of proteins, especially bromodomain-containing protein 4 (BRD4), has emerged as exciting anti-tumor targets due to their important roles in epigenetic regulation. Therefore, the discovery of BET inhibitors with promising anti-tumor efficacy will provide a novel approach to epigenetic anticancer therapy. Recently, we discovered the new BET inhibitor compound 171, which is derived from a polo-like kinase 1 (PLK1)-BRD4 dual inhibitor based on our previous research. Compound 171 was found to maintain BET inhibition ability without PLK1 inhibition, and there was no selectivity among BET family members. The in vitro and in vivo results both indicated that the overall anti-tumor activity of compound 171 was improved compared with the (+)-JQ-1 or OTX-015 BET inhibitors. Furthermore, we found that compound 171 could regulate the expression of cell cycle-regulating proteins including c-Myc and p21 and induce cell cycle arrest in the G0/G1 phase. However, compound 171 only has a quite limited effect on apoptosis, in considering that apoptosis was only observed at doses greater than 50 µM. To determine the mechanisms underlying cell death, proliferation activity assay was conducted. The results showed that compound 171 induced clear anti-proliferative effects at doses that no obvious apoptosis was induced, which indicated that the cell cycle arresting effect contributed mostly to its anti-tumor activity. The result of this study revealed the anti-tumor mechanism of compound 171, and laid a foundation for the combination therapy in clinical practice, if compound 171 or its series compounds become drug candidates in the future.
Assuntos
Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Proteínas/antagonistas & inibidores , Células A549 , Animais , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Epigênese Genética/efeitos dos fármacos , Fase G1/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HT29 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Células PC-3 , Fase de Repouso do Ciclo Celular/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
Tranylcypromine moiety extracted from LSD1 inhibitors and 6-trifluoroethyl thienopyrimidine moiety from menin-MLL1 PPI inhibitors were merged to give new chemotypes for medicinal chemistry study. Among 15 new compounds prepared in this work, some exhibited nanomolar LSD1 activity and good selectivity over MAO-A/B, low micromolar menin-MLL1 PPI inhibitory activity, as well as submicromolar MV4-11 antiprofilative activities. Intracellular LSD1 engagement of compounds with higher enzymatic and antiproliferative activities was confirmed by CD86 mRNA up-regulation experiments.
Assuntos
Antineoplásicos/farmacologia , Histona Desmetilases/antagonistas & inibidores , Inibidores da Monoaminoxidase/farmacologia , Pirimidinas/farmacologia , Tranilcipromina/farmacologia , Antineoplásicos/síntese química , Antígeno B7-2/genética , Linhagem Celular Tumoral , Humanos , Monoaminoxidase/metabolismo , Inibidores da Monoaminoxidase/síntese química , Pirimidinas/síntese química , RNA Mensageiro/metabolismo , Tiofenos/síntese química , Tiofenos/farmacologia , Tranilcipromina/análogos & derivados , Tranilcipromina/síntese química , Regulação para Cima/efeitos dos fármacosRESUMO
Rheumatoid arthritis (RA) is the second common rheumatic immune disease with chronic, invasive inflammatory characteristics. Non-steroidal anti-inflammatory drugs (NSAIDs), slow-acting anti-rheumatic drugs (SAARDs), or glucocorticoid drugs can improve RA patients’ symptoms, but fail to cure. Broton’s tyrosine kinase (BTK) inhibitors have been proven to be an efficacious target against autoimmune indications and B-cell malignancies. Among the current 11 clinical drugs, only BMS-986142, classified as a carbazole derivative, is used for treating RA. To design novel and highly potent carbazole inhibitors, molecular docking and three dimensional quantitative structureâ»activity relationship (3D-QSAR) were applied to explore a dataset of 132 new carbazole carboxamide derivatives. The established comparative molecular field analysis (CoMFA) (q² = 0.761, r² = 0.933) and comparative molecular similarity indices analysis (CoMSIA) (q² = 0.891, r² = 0.988) models obtained high predictive and satisfactory values. CoMFA/CoMSIA contour maps demonstrated that bulky substitutions and hydrogen-bond donors were preferred at R1 and 1-position, respectively, and introducing hydrophilic substitutions at R1 and R4 was important for improving BTK inhibitory activities. These results will contribute to the design of novel and highly potent BTK inhibitors.
Assuntos
Carbazóis/química , Carbazóis/farmacologia , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Tirosina Quinase da Agamaglobulinemia , Humanos , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Simulação de Acoplamento Molecular , Ligação Proteica , Proteínas Tirosina Quinases/química , Proteínas Tirosina Quinases/metabolismo , Relação Quantitativa Estrutura-AtividadeRESUMO
Fibroblast growth factor receptors (FGFRs), a subfamily of receptor tyrosine kinases, are aberrant in various cancer types, and considered to be promising targets for cancer therapy. We started with a weak-active compound that was identified from our internal hepatocyte growth factor receptor (also called c-Met) inhibitor project, and optimized it with the guidance of a co-crystal structure of compound 8 with FGFR1. Through rational design, synthesis, and the biological evaluation of a series of 5H-pyrrolo[2,3-b]pyrazine derivatives, we discovered several potent FGFR kinase inhibitors. Among them, compound 13 displayed high selectivity and favorable metabolic properties, demonstrating a promising lead for further development.
Assuntos
Descoberta de Drogas , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Receptores de Fatores de Crescimento de Fibroblastos/antagonistas & inibidores , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Humanos , Concentração Inibidora 50 , Simulação de Acoplamento Molecular , Receptores de Fatores de Crescimento de Fibroblastos/metabolismo , Relação Estrutura-AtividadeRESUMO
From a readily available 5-C-Me ribofuranoside, we have realized a reliable route to valuable 5'-deoxy-5'-amino-5'-C-methyl adenosine derivatives at gram scale with confirmed stereochemistry. These adenosine derivatives are useful starting materials for the preparation of 5'-deoxy-5'-amino-5'-C-methyl adenosine derivatives with higher complexity. From one of the new adenosine derivatives, some 5'-deoxy-5'-amino-5'-C-methyl adenosine DOT1L inhibitors were prepared in several steps. Data from DOT1L assay indicated that additional 5'-C-Me group improved the enzyme inhibitory activity.
Assuntos
Adenosina/análogos & derivados , Metiltransferases/antagonistas & inibidores , Adenosina/síntese química , Adenosina/metabolismo , Histona-Lisina N-Metiltransferase , Humanos , Concentração Inibidora 50 , Metiltransferases/metabolismo , Nucleosídeos/síntese química , Nucleosídeos/química , Nucleosídeos/metabolismo , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Phosphodiesterases are important enzymes regulating signal transduction mediated by second messenger molecules cAMP or cGMP. PDE10A is a unique member in the PDE family because of its selective expression in medium spiny neurons. It is recognized as anti-psychotic drug target. Based on the structural similarity between our previous chemistry work on 8-aminoimidazo[1,2-a]pyrazines and the PDE10A inhibitors reported by Bartolome-Nebreda et al., we initialized a project for developing PDE10A inhibitors. After several rounds of optimization, we were able to obtain a few compounds with good PDE10A enzymatic activity. And after further PDE enzymatic selectivity study, metabolic stability assay and in vivo pharmacological tests we identified two inhibitors as interesting lead compounds with the potential for further PDE10A lead optimizatioin.
Assuntos
Desenho de Fármacos , Diester Fosfórico Hidrolases/metabolismo , Purinas/farmacologia , Animais , Relação Dose-Resposta a Droga , Humanos , Locomoção/efeitos dos fármacos , Masculino , Camundongos , Microssomos/química , Microssomos/metabolismo , Estrutura Molecular , Inibição Pré-Pulso/efeitos dos fármacos , Purinas/síntese química , Purinas/química , Ratos , Ratos Sprague-Dawley , Relação Estrutura-AtividadeRESUMO
Abnormality of fibroblast growth factor receptor (FGFR)-mediated signaling pathways were frequently found in various human malignancies, making FGFRs hot targets for cancer treatment. To address the consistent need for a new chemotype of FGFR inhibitors, here, we started with a hit structure identified from our internal hepatocyte growth factor receptor (also called c-Met) inhibitor project, and conducted a chemical optimization. After exploring three parts of the hit compound, we finally discovered a new series of pyrrolo[2,3-b]pyrazine FGFR inhibitors, which contain a novel scaffold and unique molecular shape. We believe that our findings can help others to further develop selective FGFR inhibitors.
Assuntos
Pirazinas/química , Pirazinas/farmacologia , Receptores de Fatores de Crescimento de Fibroblastos/antagonistas & inibidores , Receptores de Fatores de Crescimento de Fibroblastos/química , Sítios de Ligação , Domínio Catalítico , Ativação Enzimática , Concentração Inibidora 50 , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Ligação Proteica , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Relação Estrutura-AtividadeRESUMO
An efficient one-pot synthesis of α-iminonitriles from readily available aryl halides via palladium-catalyzed double isocyanide insertion and elimination has been developed, without using various hypertoxic cyanides and excess oxidants. Furthermore, the utility of this reaction was demonstrated by the rapid total synthesis of quinoxaline and the reaction of functional groups exchanged with aryl halides.
RESUMO
The histone methylation on lysine residues is one of the most studied post-translational modifications, and its aberrant states have been associated with many human diseases. In 2012, Kruidenier et al. reported GSK-J1 as a selective Jumonji H3K27 demethylase (JMJD3 and UTX) inhibitor. However, there is limited information on the structure-activity relationship of this series of compounds. Moreover, there are few scaffolds reported as chelating groups for Fe(II) ion in Jumonji demethylase inhibitors development. To further elaborate the structure-activity relationship of selective JMJD3 inhibitors and to explore the novel chelating groups for Fe(II) ion, we initialized a medicinal chemistry modification based on the GSK-J1 structure. Finally, we found that several compounds bearing different chelating groups showed similar activities with respect to GSK-J1 and excellent metabolic stability in liver microsomes. The ethyl ester prodrugs of these inhibitors also showed a better activity than GSK-J4 for inhibition of TNF-α production in LPS-stimulated murine macrophage cell line Raw 264.7 cells. Taking together, the current study not only discovered alternative potent JMJD3 inhibitors, but also can benefit other researchers to design new series of Jumonji demethylase inhibitors based on the identified chelating groups.
Assuntos
Desenho de Fármacos , Inibidores Enzimáticos/farmacologia , Compostos Ferrosos/farmacologia , Histona Desmetilases com o Domínio Jumonji/antagonistas & inibidores , Pirimidinas/química , Animais , Linhagem Celular , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/síntese química , Compostos Ferrosos/síntese química , Compostos Ferrosos/química , Meia-Vida , Humanos , Concentração Inibidora 50 , Íons/química , Histona Desmetilases com o Domínio Jumonji/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Microssomos Hepáticos/metabolismo , Nitrogênio/química , Ligação Proteica , Pirimidinas/metabolismo , Pirimidinas/farmacocinética , Relação Estrutura-Atividade , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Menin is an essential oncogenic cofactor for mixed lineage leukemia (MLL)-mediated leukemogenesis, functioning through its direct interaction with MLL1 protein. Therefore, targeting the menin-MLL1 protein-protein interface represents a promising strategy to block MLL-mediated leukemogenesis. On the basis of co-crystal structure analysis, starting from thienopyrimidine chemotype, we have investigated the detailed structure-activity relationship of the piperazinyl-dihydrothiazole moiety. Several compounds were found with potent inhibitory activity against menin and better activities in cell-based experiments than MI-2-2. Molecular docking analysis revealed a less explored subpocket, which could be used for the design of new menin-MLL1 inhibitors.
Assuntos
Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Proteína de Leucina Linfoide-Mieloide/antagonistas & inibidores , Piperidinas/química , Piperidinas/farmacologia , Linhagem Celular Tumoral , Cristalografia por Raios X , Desenho de Fármacos , Histona-Lisina N-Metiltransferase/química , Humanos , Simulação de Acoplamento Molecular , Proteína de Leucina Linfoide-Mieloide/química , Piperidinas/síntese química , Relação Estrutura-AtividadeRESUMO
AIM: Fragment-based lead discovery (FBLD) is a complementary approach in drug research and development. In this study, we established an NMR-based FBLD platform that was used to screen novel scaffolds targeting human bromodomain of BRD4, and investigated the binding interactions between hit compounds and the target protein. METHODS: 1D NMR techniques were primarily used to generate the fragment library and to screen compounds. The inhibitory activity of hits on the first bromodomain of BRD4 [BRD4(I)] was examined using fluorescence anisotropy binding assay. 2D NMR and X-ray crystallography were applied to characterize the binding interactions between hit compounds and the target protein. RESULTS: An NMR-based fragment library containing 539 compounds was established, which were clustered into 56 groups (8-10 compounds in each group). Eight hits with new scaffolds were found to inhibit BRD4(I). Four out of the 8 hits (compounds 1, 2, 8 and 9) had IC50 values of 100-260 µmol/L, demonstrating their potential for further BRD4-targeted hit-to-lead optimization. Analysis of the binding interactions revealed that compounds 1 and 2 shared a common quinazolin core structure and bound to BRD4(I) in a non-acetylated lysine mimetic mode. CONCLUSION: An NMR-based platform for FBLD was established and used in discovery of BRD4-targeted compounds. Four potential hit-to-lead optimization candidates have been found, two of them bound to BRD4(I) in a non-acetylated lysine mimetic mode, being selective BRD4(I) inhibitors.
Assuntos
Descoberta de Drogas/métodos , Ensaios de Triagem em Larga Escala/métodos , Proteínas Nucleares/antagonistas & inibidores , Fatores de Transcrição/antagonistas & inibidores , Proteínas de Ciclo Celular , Polarização de Fluorescência , Humanos , Ressonância Magnética Nuclear Biomolecular , Ligação Proteica , Bibliotecas de Moléculas Pequenas , Relação Estrutura-AtividadeRESUMO
AIM: Aberrant c-Met activation plays a critical role in cancer formation, progression and dissemination, as well as in development of resistance to anticancer drugs. Therefore, c-Met has emerged as an attractive target for cancer therapy. The aim of this study was to develop new c-Met inhibitors and elaborate the structure-activity relationships of identified inhibitors. METHODS: Based on the predicted binding modes of Compounds 5 and 14 in docking studies, a new series of c-Met inhibitor-harboring 3-((1H-pyrrolo[3,2-c]pyridin-1-yl)sulfonyl)imidazo[1,2-a]pyridine scaffolds was discovered. Potent inhibitors were identified through extensive optimizations combined with enzymatic and cellular assays. A promising compound was further investigated in regard to its selectivity, its effects on c-Met signaling, cell proliferation and cell scattering in vitro. RESULTS: The most potent Compound 31 inhibited c-Met kinase activity with an IC50 value of 12.8 nmol/L, which was >78-fold higher than those of a panel of 16 different tyrosine kinases. Compound 31 (8, 40, 200 nmol/L) dose-dependently inhibited the phosphorylation of c-Met and its key downstream Akt and ERK signaling cascades in c-Met aberrant human EBC-1 cancer cells. In 12 human cancer cell lines harboring different background levels of c-Met expression/activation, Compound 31 potently inhibited c-Met-driven cell proliferation. Furthermore, Compound 31 dose-dependently impaired c-Met-mediated cell scattering of MDCK cells. CONCLUSION: This series of c-Met inhibitors is a promising lead for development of novel anticancer drugs.