RESUMO
Neomorphic mutations in isocitrate dehydrogenase 1 (IDH1) are oncogenic for a number of malignancies, primarily low-grade gliomas and acute myeloid leukemia. We report a medicinal chemistry campaign around a 7,7-dimethyl-7,8-dihydro-2H-1λ2-quinoline-2,5(6H)-dione screening hit against the R132H and R132C mutant forms of isocitrate dehydrogenase (IDH1). Systematic SAR efforts produced a series of potent pyrid-2-one mIDH1 inhibitors, including the atropisomer (+)-119 (NCATS-SM5637, NSC 791985). In an engineered mIDH1-U87-xenograft mouse model, after a single oral dose of 30 mg/kg, 16 h post dose, between 16 and 48 h, (+)-119 showed higher tumoral concentrations that corresponded to lower 2-HG concentrations, when compared with the approved drug AG-120 (ivosidenib).
Assuntos
Inibidores Enzimáticos/química , Isocitrato Desidrogenase/antagonistas & inibidores , Piridonas/química , Animais , Encéfalo/metabolismo , Linhagem Celular Tumoral , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/uso terapêutico , Feminino , Glicina/análogos & derivados , Glicina/uso terapêutico , Meia-Vida , Humanos , Isocitrato Desidrogenase/genética , Isocitrato Desidrogenase/metabolismo , Camundongos , Camundongos Nus , Microssomos Hepáticos/metabolismo , Mutagênese Sítio-Dirigida , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Piridinas/uso terapêutico , Piridonas/metabolismo , Piridonas/uso terapêutico , Ratos , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The histone lysine methyltransferase nuclear receptor-binding SET domain protein 2 (NSD2, also known as WHSC1/MMSET) is an epigenetic modifier and is thought to play a driving role in oncogenesis. Both NSD2 overexpression and point mutations that increase its catalytic activity are associated with several human cancers. Although NSD2 is an attractive therapeutic target, no potent, selective, and bioactive small molecule inhibitors of NSD2 have been reported to date, possibly due to the challenges of developing high-throughput assays for NSD2. Here, to establish a platform for the discovery and development of selective NSD2 inhibitors, we optimized and implemented multiple assays. We performed quantitative high-throughput screening with full-length WT NSD2 and a nucleosome substrate against a diverse collection of bioactive small molecules comprising 16,251 compounds. We further interrogated 174 inhibitory compounds identified in the primary screen with orthogonal and counter assays and with activity assays based on the clinically relevant NSD2 variants E1099K and T1150A. We selected five confirmed inhibitors for follow-up, which included a radiolabeled validation assay, surface plasmon resonance studies, methyltransferase profiling, and histone methylation in cells. We found that all five NSD2 inhibitors bind the catalytic SET domain and one exhibited apparent activity in cells, validating the workflow and providing a template for identifying selective NSD2 inhibitors. In summary, we have established a robust discovery pipeline for identifying potent NSD2 inhibitors from small-molecule libraries.
Assuntos
Avaliação Pré-Clínica de Medicamentos/métodos , Inibidores Enzimáticos/farmacologia , Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Nucleossomos/metabolismo , Proteínas Repressoras/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Linhagem Celular Tumoral , Inibidores Enzimáticos/química , Ensaios de Triagem em Larga Escala/métodos , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Nucleossomos/efeitos dos fármacos , Proteínas Repressoras/metabolismo , Bibliotecas de Moléculas Pequenas/químicaRESUMO
Isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) are key metabolic enzymes that are mutated in a variety of cancers to confer a gain-of-function activity resulting in the accumulation of an oncometabolite, D-2-hydroxyglutarate (2-HG). Accumulation of 2-HG can result in epigenetic dysregulation and a block in cellular differentiation, suggesting these mutations play a role in neoplasia. Based on its potential as a cancer target, a number of small molecule inhibitors have been developed to specifically inhibit mutant forms of IDH (mIDH1 and mIDH2). We present a comprehensive suite of in vitro preclinical drug development assays that can be used as a tool-box to identify lead compounds for mIDH drug discovery programs, as well as what we believe is the most comprehensive publically available dataset on the top mIDH inhibitors. This involved biochemical, cell-based, and tier-one ADME techniques.
Assuntos
Descoberta de Drogas , Avaliação Pré-Clínica de Medicamentos/métodos , Inibidores Enzimáticos/farmacologia , Isocitrato Desidrogenase/antagonistas & inibidores , Isocitrato Desidrogenase/genética , Mutação/genética , Diferenciação Celular/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacocinética , Estabilidade Enzimática , Fluorescência , Glutaratos/metabolismo , Ensaios de Triagem em Larga Escala , Histonas/metabolismo , Humanos , Isocitrato Desidrogenase/metabolismo , Metilação , Modelos Biológicos , Monócitos/citologia , Esferoides Celulares/efeitos dos fármacos , Esferoides Celulares/metabolismo , Células THP-1RESUMO
The efflux pump P-glycoprotein (ATP-binding cassette B1, multidrug resistance [MDR] 1, P-gp) has long been known to contribute to MDR against cancer chemotherapeutics. We describe the development of a dual-fluorescent cell line system to allow multiplexing of drug-sensitive and P-gp-mediated MDR cell lines. The parental OVCAR-8 human ovarian carcinoma cell line and the isogenic MDR NCI/ADR-RES subline, which stably expresses high levels of endogenous P-gp, were transfected to express the fluorescent proteins Discosoma sp. red fluorescent protein DsRed2 and enhanced green fluorescent protein, respectively. Co-culture conditions were defined, and fluorescent barcoding of each cell line allowed for the direct, simultaneous comparison of resistance to cytotoxic compounds in sensitive and MDR cell lines. We show that this assay system retains the phenotypes of the original lines and is suitable for multiplexing using confocal microscopy, flow cytometry, or laser scanning microplate cytometry in 1,536-well plates, enabling the high-throughput screening of large chemical libraries.