RESUMEN
Somatic mutations in the isocitrate dehydrogenase 2 gene (IDH2) contribute to the pathogenesis of acute myeloid leukaemia (AML) through the production of the oncometabolite 2-hydroxyglutarate (2HG)1-8. Enasidenib (AG-221) is an allosteric inhibitor that binds to the IDH2 dimer interface and blocks the production of 2HG by IDH2 mutants9,10. In a phase I/II clinical trial, enasidenib inhibited the production of 2HG and induced clinical responses in relapsed or refractory IDH2-mutant AML11. Here we describe two patients with IDH2-mutant AML who had a clinical response to enasidenib followed by clinical resistance, disease progression, and a recurrent increase in circulating levels of 2HG. We show that therapeutic resistance is associated with the emergence of second-site IDH2 mutations in trans, such that the resistance mutations occurred in the IDH2 allele without the neomorphic R140Q mutation. The in trans mutations occurred at glutamine 316 (Q316E) and isoleucine 319 (I319M), which are at the interface where enasidenib binds to the IDH2 dimer. The expression of either of these mutant disease alleles alone did not induce the production of 2HG; however, the expression of the Q316E or I319M mutation together with the R140Q mutation in trans allowed 2HG production that was resistant to inhibition by enasidenib. Biochemical studies predicted that resistance to allosteric IDH inhibitors could also occur via IDH dimer-interface mutations in cis, which was confirmed in a patient with acquired resistance to the IDH1 inhibitor ivosidenib (AG-120). Our observations uncover a mechanism of acquired resistance to a targeted therapy and underscore the importance of 2HG production in the pathogenesis of IDH-mutant malignancies.
Asunto(s)
Aminopiridinas/farmacología , Resistencia a Antineoplásicos/genética , Isocitrato Deshidrogenasa/antagonistas & inhibidores , Isocitrato Deshidrogenasa/genética , Leucemia Mieloide Aguda/genética , Proteínas Mutantes/genética , Mutación , Multimerización de Proteína/genética , Triazinas/farmacología , Alelos , Sitio Alostérico/efectos de los fármacos , Sitio Alostérico/genética , Aminopiridinas/química , Aminopiridinas/uso terapéutico , Animales , Ensayos Clínicos Fase I como Asunto , Ensayos Clínicos Fase II como Asunto , Progresión de la Enfermedad , Resistencia a Antineoplásicos/efectos de los fármacos , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/uso terapéutico , Femenino , Glutamina/genética , Glutaratos/sangre , Glutaratos/metabolismo , Células HEK293 , Humanos , Isoleucina/genética , Leucemia Mieloide Aguda/sangre , Leucemia Mieloide Aguda/tratamiento farmacológico , Ratones , Ratones Endogámicos C57BL , Modelos Moleculares , Proteínas Mutantes/antagonistas & inhibidores , Triazinas/química , Triazinas/uso terapéuticoRESUMEN
Metabolic regulation has been recognized as a powerful principle guiding immune responses. Inflammatory macrophages undergo extensive metabolic rewiring 1 marked by the production of substantial amounts of itaconate, which has recently been described as an immunoregulatory metabolite 2 . Itaconate and its membrane-permeable derivative dimethyl itaconate (DI) selectively inhibit a subset of cytokines 2 , including IL-6 and IL-12 but not TNF. The major effects of itaconate on cellular metabolism during macrophage activation have been attributed to the inhibition of succinate dehydrogenase2,3, yet this inhibition alone is not sufficient to account for the pronounced immunoregulatory effects observed in the case of DI. Furthermore, the regulatory pathway responsible for such selective effects of itaconate and DI on the inflammatory program has not been defined. Here we show that itaconate and DI induce electrophilic stress, react with glutathione and subsequently induce both Nrf2 (also known as NFE2L2)-dependent and -independent responses. We find that electrophilic stress can selectively regulate secondary, but not primary, transcriptional responses to toll-like receptor stimulation via inhibition of IκBζ protein induction. The regulation of IκBζ is independent of Nrf2, and we identify ATF3 as its key mediator. The inhibitory effect is conserved across species and cell types, and the in vivo administration of DI can ameliorate IL-17-IκBζ-driven skin pathology in a mouse model of psoriasis, highlighting the therapeutic potential of this regulatory pathway. Our results demonstrate that targeting the DI-IκBζ regulatory axis could be an important new strategy for the treatment of IL-17-IκBζ-mediated autoimmune diseases.
Asunto(s)
Factor de Transcripción Activador 3/metabolismo , Proteínas I-kappa B/metabolismo , Succinatos/metabolismo , Animales , Células Cultivadas , Citocinas/inmunología , Citocinas/metabolismo , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Glutatión/metabolismo , Humanos , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Interleucina-6/metabolismo , Queratinocitos/efectos de los fármacos , Queratinocitos/metabolismo , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Ratones , Ratones Endogámicos C57BL , Factor 2 Relacionado con NF-E2/metabolismo , Psoriasis/tratamiento farmacológico , Psoriasis/patología , Estrés Fisiológico/efectos de los fármacos , Succinatos/administración & dosificación , Succinatos/química , Succinatos/farmacología , Succinatos/uso terapéutico , Receptores Toll-Like/inmunologíaRESUMEN
Point mutations in isocitrate dehydrogenase 1 (IDH1) result in conversion of α-ketoglutarate to the oncometabolite, d-2-hydroxyglutarate (2-HG). Ivosidenib is a once daily (QD), orally available, potent, mutant isocitrate dehydrogenase 1 (mIDH1) inhibitor approved for the treatment of patients with relapsed or refractory acute myeloid leukemia (AML) and intensive chemotherapy-ineligible newly diagnosed AML, with a susceptible IDH1 mutation. We characterized the protein binding, metabolism, metabolites, cell permeability, and drug-drug interaction potential of ivosidenib in humans, monkeys, dogs, rats, and/or mice in in vitro experiments. In vivo pharmacokinetic (PK) profiling and assessment of drug distribution and excretion was undertaken in rats, dogs, and monkeys administered single-dose ivosidenib. The PK/pharmacodynamic (PD) relationship between ivosidenib and 2-HG was analyzed in an mIDH1 xenograft mouse model. Ivosidenib was well absorbed, showed low clearance, and moderate to long terminal half-life (5.3-18.5 hours) in rats, dogs, and monkeys. Brain to plasma exposure ratio was low (2.3%), plasma protein binding was high, and oxidative metabolism was the major elimination pathway. Ivosidenib had high cell permeability and was identified as a substrate for P-glycoprotein. There was moderate induction of cytochrome P450 (P450) enzymes CYP3A4 and CYP2B6 but minimal P450 inhibition or autoinduction. Tumor 2-HG reduction appeared to be dose- and drug-exposure-dependent. Ivosidenib showed a favorable PK profile in several animal species, along with a clear PK/PD relationship demonstrating 2-HG inhibition that translated well to patients with AML. SIGNIFICANCE STATEMENT: Ivosidenib is a mutant IDH1 (mIDH1) inhibitor approved for the treatment of certain patients with mIDH1 acute myeloid leukemia. In Sprague-Dawley rats, beagle dogs, and cynomolgus monkeys, ivosidenib demonstrated a favorable pharmacokinetic profile, and in female BALB/c mice showed clear dose- and exposure-dependent inhibition of the oncometabolite, d-2-hydroxyglutarate, which is present at abnormal levels in mIDH1 tumors. These findings led to the further development of ivosidenib and are consistent with data from patients with mIDH1 cancers and healthy participants.
Asunto(s)
Glicina/análogos & derivados , Isocitrato Deshidrogenasa/metabolismo , Leucemia Mieloide Aguda , Piridinas/farmacocinética , Animales , Antineoplásicos/farmacocinética , Sistema Enzimático del Citocromo P-450/metabolismo , Perros , Relación Dosis-Respuesta a Droga , Vías de Eliminación de Fármacos , Interacciones Farmacológicas , Glutaratos/metabolismo , Glicina/farmacocinética , Haplorrinos , Humanos , Isocitrato Deshidrogenasa/antagonistas & inhibidores , Isocitrato Deshidrogenasa/genética , Ácidos Cetoglutáricos/metabolismo , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/genética , Tasa de Depuración Metabólica , Ratones , Mutación Puntual , Unión Proteica , Ratas , Ensayos Antitumor por Modelo de Xenoinjerto/métodosRESUMEN
Pyruvate kinase (PK) deficiency is a rare genetic disease that causes chronic hemolytic anemia. There are currently no targeted therapies for PK deficiency. Here, we describe the identification and characterization of AG-348, an allosteric activator of PK that is currently in clinical trials for the treatment of PK deficiency. We demonstrate that AG-348 can increase the activity of wild-type and mutant PK enzymes in biochemical assays and in patient red blood cells treated ex vivo. These data illustrate the potential for AG-348 to restore the glycolytic pathway activity in patients with PK deficiency and ultimately lead to clinical benefit.
Asunto(s)
Activadores de Enzimas/farmacología , Activadores de Enzimas/uso terapéutico , Eritrocitos/enzimología , Piruvato Quinasa/deficiencia , Piruvato Quinasa/metabolismo , Quinolinas/farmacología , Quinolinas/uso terapéutico , Sulfonamidas/farmacología , Sulfonamidas/uso terapéutico , Anemia Hemolítica Congénita no Esferocítica , Animales , Activación Enzimática/efectos de los fármacos , Activadores de Enzimas/química , Eritrocitos/efectos de los fármacos , Humanos , Cinética , Ratones , Piperazinas , Piruvato Quinasa/efectos de los fármacos , Errores Innatos del Metabolismo del Piruvato , Quinolinas/química , Proteínas Recombinantes/metabolismo , Sulfonamidas/química , Donantes de TejidosRESUMEN
Mitochondrial aldehyde dehydrogenase 2 (ALDH2) in the liver removes toxic aldehydes including acetaldehyde, an intermediate of ethanol metabolism. Nearly 40% of East Asians inherit an inactive ALDH2*2 variant, which has a lysine-for-glutamate substitution at position 487 (E487K), and show a characteristic alcohol flush reaction after drinking and a higher risk for gastrointestinal cancers. Here we report the characterization of knockin mice in which the ALDH2(E487K) mutation is inserted into the endogenous murine Aldh2 locus. These mutants recapitulate essentially all human phenotypes including impaired clearance of acetaldehyde, increased sensitivity to acute or chronic alcohol-induced toxicity, and reduced ALDH2 expression due to a dominant-negative effect of the mutation. When treated with a chemical carcinogen, these mutants exhibit increased DNA damage response in hepatocytes, pronounced liver injury, and accelerated development of hepatocellular carcinoma (HCC). Importantly, ALDH2 protein levels are also significantly lower in patient HCC than in peritumor or normal liver tissues. Our results reveal that ALDH2 functions as a tumor suppressor by maintaining genomic stability in the liver, and the common human ALDH2 variant would present a significant risk factor for hepatocarcinogenesis. Our study suggests that the ALDH2*2 allele-alcohol interaction may be an even greater human public health hazard than previously appreciated.
Asunto(s)
Aldehído Deshidrogenasa/genética , Carcinoma Hepatocelular/enzimología , Neoplasias Hepáticas/enzimología , Neoplasias Hepáticas/genética , Mutación/genética , Intoxicación Alcohólica/enzimología , Intoxicación Alcohólica/patología , Aldehído Deshidrogenasa Mitocondrial , Sustitución de Aminoácidos , Animales , Secuencia de Bases , Carcinogénesis/patología , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patología , Etanol/efectos adversos , Técnicas de Sustitución del Gen , Técnicas de Genotipaje , Hepatocitos/enzimología , Hepatocitos/patología , Humanos , Hiperpigmentación/patología , Inmunohistoquímica , Hígado/enzimología , Hígado/patología , Neoplasias Hepáticas/patología , Ratones Endogámicos C57BL , Proteínas Mutantes/metabolismo , Polimorfismo Genético , Complejo de la Endopetidasa Proteasomal/metabolismo , Estabilidad Proteica , Piel/patología , Análisis de SupervivenciaRESUMEN
Mutations of IDH1 and IDH2, which produce the oncometabolite 2-hydroxyglutarate (2HG), have been identified in several tumors, including acute myeloid leukemia. Recent studies have shown that expression of the IDH mutant enzymes results in high levels of 2HG and a block in cellular differentiation that can be reversed with IDH mutant-specific small-molecule inhibitors. To further understand the role of IDH mutations in cancer, we conducted mechanistic studies in the TF-1 IDH2 R140Q erythroleukemia model system and found that IDH2 mutant expression caused both histone and genomic DNA methylation changes that can be reversed when IDH2 mutant activity is inhibited. Specifically, histone hypermethylation is rapidly reversed within days, whereas reversal of DNA hypermethylation proceeds in a progressive manner over the course of weeks. We identified several gene signatures implicated in tumorigenesis of leukemia and lymphoma, indicating a selective modulation of relevant cancer genes by IDH mutations. As methylation of DNA and histones is closely linked to mRNA expression and differentiation, these results indicate that IDH2 mutant inhibition may function as a cancer therapy via histone and DNA demethylation at genes involved in differentiation and tumorigenesis.
Asunto(s)
Metilación de ADN/genética , Inhibidores Enzimáticos/farmacología , Histonas/genética , Isocitrato Deshidrogenasa/genética , Mutación , Transcriptoma/efectos de los fármacos , Línea Celular Tumoral , Inmunoprecipitación de Cromatina , Cromatografía Liquida , Histonas/efectos de los fármacos , Humanos , Leucemia Mieloide Aguda/genética , Compuestos de Fenilurea/farmacología , Análisis de Componente Principal , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sulfonamidas/farmacología , Espectrometría de Masas en TándemRESUMEN
D-2-hydroxyglutaric aciduria (D2HGA) type II is a rare neurometabolic disorder caused by germline gain-of-function mutations in isocitrate dehydrogenase 2 (IDH2), resulting in accumulation of D-2-hydroxyglutarate (D2HG). Patients exhibit a wide spectrum of symptoms including cardiomyopathy, epilepsy, developmental delay and limited life span. Currently, there are no effective therapeutic interventions. We generated a D2HGA type II mouse model by introducing the Idh2R140Q mutation at the native chromosomal locus. Idh2R140Q mice displayed significantly elevated 2HG levels and recapitulated multiple defects seen in patients. AGI-026, a potent, selective inhibitor of the human IDH2R140Q-mutant enzyme, suppressed 2HG production, rescued cardiomyopathy, and provided a survival benefit in Idh2R140Q mice; treatment withdrawal resulted in deterioration of cardiac function. We observed differential expression of multiple genes and metabolites that are associated with cardiomyopathy, which were largely reversed by AGI-026. These findings demonstrate the potential therapeutic benefit of an IDH2R140Q inhibitor in patients with D2HGA type II.
Asunto(s)
Encefalopatías Metabólicas Innatas/tratamiento farmacológico , Cardiomiopatías/tratamiento farmacológico , Isocitrato Deshidrogenasa/antagonistas & inhibidores , Mutación/efectos de los fármacos , Bibliotecas de Moléculas Pequeñas/farmacología , Animales , Encefalopatías Metabólicas Innatas/genética , Modelos Animales de Enfermedad , Isocitrato Deshidrogenasa/genética , Ratones , Mutación/genéticaRESUMEN
Communication of data and ideas within a medicinal chemistry project on a global as well as local level is a crucial aspect in the drug design cycle. Over a time frame of eight years, we built and optimized FOCUS, a platform to produce, visualize, and share information on various aspects of a drug discovery project such as cheminformatics, data analysis, structural information, and design. FOCUS is tightly integrated with internal services that involve-among others-data retrieval systems and in-silico models and provides easy access to automated modeling procedures such as pharmacophore searches, R-group analysis, and similarity searches. In addition, an interactive 3D editor was developed to assist users in the generation and docking of close analogues of a known lead. In this paper, we will specifically concentrate on issues we faced during development, deployment, and maintenance of the software and how we continually adapted the software in order to improve usability. We will provide usage examples to highlight the functionality as well as limitations of FOCUS at the various stages of the development process. We aim to make the discussion as independent of the software platform as possible, so that our experiences can be of more general value to the drug discovery community.
Asunto(s)
Química Farmacéutica/métodos , Comunicación , Simulación por Computador , Descubrimiento de Drogas/métodos , Biología Computacional , LigandosRESUMEN
Inhibition of the S-adenosyl methionine (SAM)-producing metabolic enzyme, methionine adenosyltransferase 2A (MAT2A), has received significant interest in the field of medicinal chemistry due to its implication as a synthetic lethal target in cancers with the deletion of the methylthioadenosine phosphorylase (MTAP) gene. Here, we report the identification of novel MAT2A inhibitors with distinct in vivo properties that may enhance their utility in treating patients. Following a high-throughput screening, we successfully applied the structure-based design lessons from our first-in-class MAT2A inhibitor, AG-270, to rapidly redesign and optimize our initial hit into two new lead compounds: a brain-penetrant compound, AGI-41998, and a potent, but limited brain-penetrant compound, AGI-43192. We hope that the identification and first disclosure of brain-penetrant MAT2A inhibitors will create new opportunities to explore the potential therapeutic effects of SAM modulation in the central nervous system (CNS).
Asunto(s)
Metionina Adenosiltransferasa , Neoplasias , Encéfalo/metabolismo , Diseño de Fármacos , Humanos , Neoplasias/tratamiento farmacológico , S-Adenosilmetionina/metabolismoRESUMEN
The metabolic enzyme methionine adenosyltransferase 2A (MAT2A) was recently implicated as a synthetic lethal target in cancers with deletion of the methylthioadenosine phosphorylase (MTAP) gene, which is adjacent to the CDKN2A tumor suppressor and codeleted with CDKN2A in approximately 15% of all cancers. Previous attempts to target MAT2A with small-molecule inhibitors identified cellular adaptations that blunted their efficacy. Here, we report the discovery of highly potent, selective, orally bioavailable MAT2A inhibitors that overcome these challenges. Fragment screening followed by iterative structure-guided design enabled >10â¯000-fold improvement in potency of a family of allosteric MAT2A inhibitors that are substrate noncompetitive and inhibit release of the product, S-adenosyl methionine (SAM), from the enzyme's active site. We demonstrate that potent MAT2A inhibitors substantially reduce SAM levels in cancer cells and selectively block proliferation of MTAP-null cells both in tissue culture and xenograft tumors. These data supported progressing AG-270 into current clinical studies (ClinicalTrials.gov NCT03435250).
Asunto(s)
Inhibidores Enzimáticos/química , Metionina Adenosiltransferasa/antagonistas & inhibidores , Purina-Nucleósido Fosforilasa/genética , Sitios de Unión , Cristalografía por Rayos X , Diseño de Fármacos , Inhibidores Enzimáticos/metabolismo , Inhibidores Enzimáticos/uso terapéutico , Homocigoto , Humanos , Metionina Adenosiltransferasa/metabolismo , Simulación de Dinámica Molecular , Neoplasias/tratamiento farmacológico , Purina-Nucleósido Fosforilasa/metabolismo , S-Adenosilmetionina/metabolismo , Relación Estructura-ActividadRESUMEN
The methylthioadenosine phosphorylase (MTAP) gene is located adjacent to the cyclin-dependent kinase inhibitor 2A (CDKN2A) tumor-suppressor gene and is co-deleted with CDKN2A in approximately 15% of all cancers. This co-deletion leads to aggressive tumors with poor prognosis that lack effective, molecularly targeted therapies. The metabolic enzyme methionine adenosyltransferase 2α (MAT2A) was identified as a synthetic lethal target in MTAP-deleted cancers. We report the characterization of potent MAT2A inhibitors that substantially reduce levels of S-adenosylmethionine (SAM) and demonstrate antiproliferative activity in MTAP-deleted cancer cells and tumors. Using RNA sequencing and proteomics, we demonstrate that MAT2A inhibition is mechanistically linked to reduced protein arginine methyltransferase 5 (PRMT5) activity and splicing perturbations. We further show that DNA damage and mitotic defects ensue upon MAT2A inhibition in HCT116 MTAP-/- cells, providing a rationale for combining the MAT2A clinical candidate AG-270 with antimitotic taxanes.
Asunto(s)
Daño del ADN/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Metionina Adenosiltransferasa/antagonistas & inhibidores , Proteína-Arginina N-Metiltransferasas/genética , Purina-Nucleósido Fosforilasa/genética , Empalme del ARN/efectos de los fármacos , ARN Mensajero/genética , Animales , Línea Celular , Línea Celular Tumoral , Inhibidor p16 de la Quinasa Dependiente de Ciclina , Daño del ADN/genética , Eliminación de Gen , Células HCT116 , Células HEK293 , Humanos , Metionina Adenosiltransferasa/genética , Ratones Endogámicos NOD , Ratones Desnudos , Ratones SCID , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Empalme del ARN/genética , S-Adenosilmetionina/metabolismoRESUMEN
Agents targeting metabolic pathways form the backbone of standard oncology treatments, though a better understanding of differential metabolic dependencies could instruct more rationale-based therapeutic approaches. We performed a chemical biology screen that revealed a strong enrichment in sensitivity to a novel dihydroorotate dehydrogenase (DHODH) inhibitor, AG-636, in cancer cell lines of hematologic versus solid tumor origin. Differential AG-636 activity translated to the in vivo setting, with complete tumor regression observed in a lymphoma model. Dissection of the relationship between uridine availability and response to AG-636 revealed a divergent ability of lymphoma and solid tumor cell lines to survive and grow in the setting of depleted extracellular uridine and DHODH inhibition. Metabolic characterization paired with unbiased functional genomic and proteomic screens pointed to adaptive mechanisms to cope with nucleotide stress as contributing to response to AG-636. These findings support targeting of DHODH in lymphoma and other hematologic malignancies and suggest combination strategies aimed at interfering with DNA-damage response pathways.
Asunto(s)
Antineoplásicos/farmacología , Inhibidores Enzimáticos/farmacología , Neoplasias Hematológicas/metabolismo , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH/antagonistas & inhibidores , Pirimidinas/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Daño del ADN/efectos de los fármacos , Dihidroorotato Deshidrogenasa , Genómica/métodos , Neoplasias Hematológicas/tratamiento farmacológico , Neoplasias Hematológicas/etiología , Neoplasias Hematológicas/patología , Humanos , Estadificación de Neoplasias , Proteómica/métodosRESUMEN
Isocitrate dehydrogenase (IDH) 1 and 2 mutations result in overproduction of D-2-hydroxyglutarate (2-HG) and impaired cellular differentiation. Ivosidenib, a targeted mutant IDH1 (mIDH1) enzyme inhibitor, can restore normal differentiation and results in clinical responses in a subset of patients with mIDH1 relapsed/refractory (R/R) acute myeloid leukemia (AML). We explored mechanisms of ivosidenib resistance in 174 patients with confirmed mIDH1 R/R AML from a phase 1 trial. Receptor tyrosine kinase (RTK) pathway mutations were associated with primary resistance to ivosidenib. Multiple mechanisms contributed to acquired resistance, particularly outgrowth of RTK pathway mutations and 2-HG-restoring mutations (second-site IDH1 mutations, IDH2 mutations). Observation of multiple concurrent mechanisms in individual patients underscores the complex biology of resistance and has important implications for rational combination therapy design. This trial was registered at www.clinicaltrials.gov as #NCT02074839.
Asunto(s)
Isocitrato Deshidrogenasa , Leucemia Mieloide Aguda , Glicina/análogos & derivados , Humanos , Isocitrato Deshidrogenasa/genética , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/genética , Piridinas , RecurrenciaRESUMEN
Inhibitors of mutant isocitrate dehydrogenase (mIDH) 1 and 2 cancer-associated enzymes prevent the accumulation of the oncometabolite d-2-hydroxyglutarate (2-HG) and are under clinical investigation for the treatment of several cancers harboring an IDH mutation. Herein, we describe the discovery of vorasidenib (AG-881), a potent, oral, brain-penetrant dual inhibitor of both mIDH1 and mIDH2. X-ray cocrystal structures allowed us to characterize the compound binding site, leading to an understanding of the dual mutant inhibition. Furthermore, vorasidenib penetrates the brain of several preclinical species and inhibits 2-HG production in glioma tissue by >97% in an orthotopic glioma mouse model. Vorasidenib represents a novel dual mIDH1/2 inhibitor and is currently in clinical development for the treatment of low-grade mIDH glioma.
RESUMEN
Squalene epoxidase (SQLE), also known as squalene monooxygenase, catalyzes the stereospecific conversion of squalene to 2,3(S)-oxidosqualene, a key step in cholesterol biosynthesis. SQLE inhibition is targeted for the treatment of hypercholesteremia, cancer, and fungal infections. However, lack of structure-function understanding has hindered further progression of its inhibitors. We have determined the first three-dimensional high-resolution crystal structures of human SQLE catalytic domain with small molecule inhibitors (2.3 Å and 2.5 Å). Comparison with its unliganded state (3.0 Å) reveals conformational rearrangements upon inhibitor binding, thus allowing deeper interpretation of known structure-activity relationships. We use the human SQLE structure to further understand the specificity of terbinafine, an approved agent targeting fungal SQLE, and to provide the structural insights into terbinafine-resistant mutants encountered in the clinic. Collectively, these findings elucidate the structural basis for the specificity of the epoxidation reaction catalyzed by SQLE and enable further rational development of next-generation inhibitors.
Asunto(s)
Escualeno-Monooxigenasa/química , Escualeno-Monooxigenasa/metabolismo , Animales , Dominio Catalítico , Línea Celular , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Humanos , Insectos , Conformación Proteica , Dominios Proteicos , Escualeno/metabolismo , Escualeno-Monooxigenasa/antagonistas & inhibidoresRESUMEN
Aberrant metabolism of cancer cells is well appreciated, but the identification of cancer subsets with specific metabolic vulnerabilities remains challenging. We conducted a chemical biology screen and identified a subset of neuroendocrine tumors displaying a striking pattern of sensitivity to inhibition of the cholesterol biosynthetic pathway enzyme squalene epoxidase (SQLE). Using a variety of orthogonal approaches, we demonstrate that sensitivity to SQLE inhibition results not from cholesterol biosynthesis pathway inhibition, but rather surprisingly from the specific and toxic accumulation of the SQLE substrate, squalene. These findings highlight SQLE as a potential therapeutic target in a subset of neuroendocrine tumors, particularly small cell lung cancers.
Asunto(s)
Antineoplásicos/farmacología , Sistemas de Liberación de Medicamentos , Ensayos de Selección de Medicamentos Antitumorales , Escualeno-Monooxigenasa/antagonistas & inhibidores , Escualeno-Monooxigenasa/metabolismo , Antineoplásicos/química , Línea Celular Tumoral , Colesterol/biosíntesis , Eliminación de Gen , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , HumanosRESUMEN
The C-aryl glucoside 6 (dapagliflozin) was identified as a potent and selective hSGLT2 inhibitor which reduced blood glucose levels in a dose-dependent manner by as much as 55% in hyperglycemic streptozotocin (STZ) rats. These findings, combined with a favorable ADME profile, have prompted clinical evaluation of dapagliflozin for the treatment of type 2 diabetes.
Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Glucósidos/síntesis química , Hipoglucemiantes/síntesis química , Riñón/metabolismo , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Administración Oral , Animales , Compuestos de Bencidrilo , Glucemia/metabolismo , Diabetes Mellitus Experimental/tratamiento farmacológico , Glucósidos/química , Glucósidos/farmacología , Humanos , Hipoglucemiantes/química , Hipoglucemiantes/farmacología , Ratas , Transportador 2 de Sodio-Glucosa , EstereoisomerismoRESUMEN
A novel series of N1 substituted tetrazole amides were prepared and showed to be potent growth hormone (GH) secretagogues. Among them, hydroxyl containing analog 31 displayed excellent in vivo activity by increasing plasma GH 10-fold in an anesthetized IV rat model.
Asunto(s)
Amidas/síntesis química , Amidas/farmacología , Hormona del Crecimiento/metabolismo , Tetrazoles/química , Amidas/química , Animales , Línea Celular , Glioma/metabolismo , Hormona del Crecimiento/sangre , Estructura Molecular , Ratas , Relación Estructura-ActividadRESUMEN
1H-tetrazole-1-alkanenitrile SR-9g exhibits a >10-fold in vivo potency enhancement over the lead nitrile 1 and has acceptable oral bioavailability in rats and dogs. An enantiospecific synthesis of 1H-tetrazole-1-alkanenitrile nitriles 9 has been developed.
Asunto(s)
Hormona del Crecimiento/metabolismo , Nitrilos/farmacología , Tetrazoles/farmacología , Administración Oral , Animales , Disponibilidad Biológica , Sistema Enzimático del Citocromo P-450/metabolismo , Perros , Espectroscopía de Resonancia Magnética , Estructura Molecular , Nitrilos/síntesis química , Nitrilos/farmacocinética , Hipófisis , Ratas , Relación Estructura-Actividad , Tetrazoles/síntesis química , Tetrazoles/farmacocinéticaRESUMEN
Somatic point mutations at a key arginine residue (R132) within the active site of the metabolic enzyme isocitrate dehydrogenase 1 (IDH1) confer a novel gain of function in cancer cells, resulting in the production of d-2-hydroxyglutarate (2-HG), an oncometabolite. Elevated 2-HG levels are implicated in epigenetic alterations and impaired cellular differentiation. IDH1 mutations have been described in an array of hematologic malignancies and solid tumors. Here, we report the discovery of AG-120 (ivosidenib), an inhibitor of the IDH1 mutant enzyme that exhibits profound 2-HG lowering in tumor models and the ability to effect differentiation of primary patient AML samples ex vivo. Preliminary data from phase 1 clinical trials enrolling patients with cancers harboring an IDH1 mutation indicate that AG-120 has an acceptable safety profile and clinical activity.