RESUMEN
Flavaglines such as silvestrol (1) and rocaglamide (2) constitute an interesting class of natural products with promising anticancer activities. Their mode of action is based on inhibition of eukaryotic initiation factor 4A (eIF4A) dependent translation through formation of a stable ternary complex with eIF4A and mRNA, thus blocking ribosome scanning. Herein we describe initial SAR studies in a novel series of 1-aminomethyl substituted flavagline-inspired eIF4A inhibitors. We discovered that a variety of N-substitutions at the 1-aminomethyl group are tolerated, making this position pertinent for property and ADME profile tuning. The findings presented herein are relevant to future drug design efforts towards novel eIF4A inhibitors with drug-like properties.
Asunto(s)
Antineoplásicos/farmacología , Benzofuranos/farmacología , Productos Biológicos/farmacología , Factor 4A Eucariótico de Iniciación/antagonistas & inhibidores , Triterpenos/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Benzofuranos/síntesis química , Benzofuranos/química , Productos Biológicos/síntesis química , Productos Biológicos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Diseño de Fármacos , Ensayos de Selección de Medicamentos Antitumorales , Factor 4A Eucariótico de Iniciación/metabolismo , Humanos , Estructura Molecular , Relación Estructura-Actividad , Triterpenos/síntesis química , Triterpenos/químicaRESUMEN
The PI3K/AKT/mTOR pathway is often activated in lymphoma through alterations in PI3K, PTEN, and B-cell receptor signaling, leading to dysregulation of eIF4A (through its regulators, eIF4B, eIF4G, and PDCD4) and the eIF4F complex. Activation of eIF4F has a direct role in tumorigenesis due to increased synthesis of oncogenes that are dependent on enhanced eIF4A RNA helicase activity for translation. eFT226, which inhibits translation of specific mRNAs by promoting eIF4A1 binding to 5'-untranslated regions (UTR) containing polypurine and/or G-quadruplex recognition motifs, shows potent antiproliferative activity and significant in vivo efficacy against a panel of diffuse large B-cell lymphoma (DLBCL), and Burkitt lymphoma models with ≤1 mg/kg/week intravenous administration. Evaluation of predictive markers of sensitivity or resistance has shown that activation of eIF4A, mediated by mTOR signaling, correlated with eFT226 sensitivity in in vivo xenograft models. Mutation of PTEN is associated with reduced apoptosis in vitro and diminished efficacy in vivo in response to eFT226. In models evaluated with PTEN loss, AKT was stimulated without a corresponding increase in mTOR activation. AKT activation leads to the degradation of PDCD4, which can alter eIF4F complex formation. The association of eFT226 activity with PTEN/PI3K/mTOR pathway regulation of mRNA translation provides a means to identify patient subsets during clinical development.
Asunto(s)
Factor 4A Eucariótico de Iniciación/antagonistas & inhibidores , Linfoma de Células B/genética , Linfoma de Células B/patología , Oncogenes , Biosíntesis de Proteínas/genética , ARN Mensajero/genética , Animales , Biomarcadores de Tumor/metabolismo , Línea Celular Tumoral , Resistencia a Antineoplásicos/efectos de los fármacos , Factor 4A Eucariótico de Iniciación/metabolismo , Femenino , Humanos , Ratones Endogámicos NOD , Ratones SCID , Fosfohidrolasa PTEN/metabolismo , ARN Mensajero/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Rocaglates, rocaglamides, and related flavagline natural products exert their remarkable anticancer activity through inhibition of eukaryotic initiation factor 4A (eIF4A) but generally display suboptimal drug-like properties. In our efforts to identify potent drug-like eIF4A inhibitors, we developed synthetic strategies for diastereoselectively functionalizing the C1 position of aza-rocaglamide scaffolds (cf. 14 and 18), which proceed via retention or inversion of configuration at C1 depending on the C2 substituent (cf. 15 and 21) and ultimately enabled the discovery of novel and potent eIF4A inhibitors such as 25.
Asunto(s)
Benzofuranos/química , Factor 4A Eucariótico de Iniciación/antagonistas & inhibidores , Sitios de Unión , Productos Biológicos , Factor 4A Eucariótico de Iniciación/metabolismo , Humanos , Estructura MolecularRESUMEN
Dysregulation of protein translation is a key driver for the pathogenesis of many cancers. Eukaryotic initiation factor 4A (eIF4A), an ATP-dependent DEAD-box RNA helicase, is a critical component of the eIF4F complex, which regulates cap-dependent protein synthesis. The flavagline class of natural products (i.e., rocaglamide A) has been shown to inhibit protein synthesis by stabilizing a translation-incompetent complex for select messenger RNAs (mRNAs) with eIF4A. Despite showing promising anticancer phenotypes, the development of flavagline derivatives as therapeutic agents has been hampered because of poor drug-like properties as well as synthetic complexity. A focused effort was undertaken utilizing a ligand-based design strategy to identify a chemotype with optimized physicochemical properties. Also, detailed mechanistic studies were undertaken to further elucidate mRNA sequence selectivity, key regulated target genes, and the associated antitumor phenotype. This work led to the design of eFT226 (Zotatifin), a compound with excellent physicochemical properties and significant antitumor activity that supports clinical development.
Asunto(s)
Benzofuranos/química , Diseño de Fármacos , Factor 4A Eucariótico de Iniciación/antagonistas & inhibidores , Animales , Benzofuranos/farmacocinética , Benzofuranos/uso terapéutico , Sitios de Unión , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Línea Celular Tumoral , Cristalografía por Rayos X , Factor 4A Eucariótico de Iniciación/genética , Factor 4A Eucariótico de Iniciación/metabolismo , Femenino , Semivida , Humanos , Ligandos , Ratones , Ratones Desnudos , Simulación de Dinámica Molecular , Mutagénesis Sitio-Dirigida , Estructura Terciaria de Proteína , ARN Mensajero/química , ARN Mensajero/metabolismo , Ratas , Relación Estructura-ActividadRESUMEN
Dysregulated translation of mRNA plays a major role in tumorigenesis. Mitogen-activated protein kinase interacting kinases (MNK)1/2 are key regulators of mRNA translation integrating signals from oncogenic and immune signaling pathways through phosphorylation of eIF4E and other mRNA binding proteins. Modulation of these key effector proteins regulates mRNA, which controls tumor/stromal cell signaling. Compound 23 (eFT508), an exquisitely selective, potent dual MNK1/2 inhibitor, was designed to assess the potential for control of oncogene signaling at the level of mRNA translation. The crystal structure-guided design leverages stereoelectronic interactions unique to MNK culminating in a novel pyridone-aminal structure described for the first time in the kinase literature. Compound 23 has potent in vivo antitumor activity in models of diffuse large cell B-cell lymphoma and solid tumors, suggesting that controlling dysregulated translation has real therapeutic potential. Compound 23 is currently being evaluated in Phase 2 clinical trials in solid tumors and lymphoma. Compound 23 is the first highly selective dual MNK inhibitor targeting dysregulated translation being assessed clinically.
Asunto(s)
Antineoplásicos/uso terapéutico , Péptidos y Proteínas de Señalización Intracelular/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Piridinas/uso terapéutico , Piridonas/uso terapéutico , Pirimidinas/uso terapéutico , Compuestos de Espiro/uso terapéutico , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Antineoplásicos/farmacología , Dominio Catalítico , Línea Celular Tumoral , Diseño de Fármacos , Factor 4E Eucariótico de Iniciación/química , Factor 4E Eucariótico de Iniciación/metabolismo , Humanos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Ratones , Estructura Molecular , Fosforilación , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Serina-Treonina Quinasas/metabolismo , Piridinas/síntesis química , Piridinas/química , Piridinas/farmacología , Piridonas/síntesis química , Piridonas/química , Piridonas/farmacología , Pirimidinas/síntesis química , Pirimidinas/química , Pirimidinas/farmacología , Ratas , Serina/química , Transducción de Señal/efectos de los fármacos , Compuestos de Espiro/síntesis química , Compuestos de Espiro/química , Compuestos de Espiro/farmacología , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
A structure-based drug design strategy was used to optimize a novel benzolactam series of HSP90α/ß inhibitors to achieve >1000-fold selectivity versus the HSP90 endoplasmic reticulum and mitochondrial isoforms (GRP94 and TRAP1, respectively). Selective HSP90α/ß inhibitors were found to be equipotent to pan-HSP90 inhibitors in promoting the clearance of mutant huntingtin protein (mHtt) in vitro, however with less cellular toxicity. Improved tolerability profiles may enable the use of HSP90α/ß selective inhibitors in treating chronic neurodegenerative indications such as Huntington's disease (HD). A potent, selective, orally available HSP90α/ß inhibitor was identified (compound 31) that crosses the blood-brain barrier. Compound 31 demonstrated proof of concept by successfully reducing brain Htt levels following oral dosing in rats.
Asunto(s)
Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Enfermedad de Huntington/tratamiento farmacológico , Animales , Diseño de Fármacos , Proteínas HSP90 de Choque Térmico/química , Humanos , Masculino , Ratas , Ratas Sprague-Dawley , Relación Estructura-ActividadRESUMEN
HSP90 continues to be a target of interest for neurodegeneration indications. Selective knockdown of the HSP90 cytosolic isoforms α and ß is sufficient to reduce mutant huntingtin protein levels in vitro. Chemotype-dependent binding conformations of HSP90α/ß appear to strongly influence isoform selectivity. The rational design of HSP90α/ß inhibitors selective versus the mitochondrial (TRAP1) and endoplasmic reticulum (GRP94) isoforms offers a potential mitigating strategy for mechanism-based toxicities. Better tolerated HSP90 inhibitors would be attractive for targeting chronic neurodegenerative diseases such as Huntington's disease.
Asunto(s)
Diseño de Fármacos , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Enfermedades Neurodegenerativas/tratamiento farmacológico , Cristalografía por Rayos X , Humanos , Modelos Moleculares , Estructura Molecular , Isoformas de Proteínas/antagonistas & inhibidoresRESUMEN
We have optimized a novel series of potent p38 MAP kinase inhibitors based on an alpha-ketoamide scaffold through structure based design that due to their extended molecular architecture bind, in addition to the ATP site, to an allosteric pocket. In vitro ADME, in vivo PK and efficacy studies show these compounds to have drug-like characteristics and have resulted in the nomination of a development candidate which is currently in phase II clinical trials for the oral treatment of inflammatory conditions.
Asunto(s)
Amidas/química , Antiinflamatorios no Esteroideos/química , Inhibidores de Proteínas Quinasas/química , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidores , Administración Oral , Sitio Alostérico , Amidas/síntesis química , Amidas/farmacología , Animales , Antiinflamatorios no Esteroideos/síntesis química , Antiinflamatorios no Esteroideos/farmacocinética , Sitios de Unión , Línea Celular , Simulación por Computador , Humanos , Unión Proteica , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacocinética , Ratas , Relación Estructura-Actividad , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
We have identified a novel series of potent p38 MAP kinase inhibitors through structure-based design which due to their extended molecular architecture bind, in addition to the ATP site, to an allosteric pocket. In vitro ADME and in vivo PK studies show these compounds to have drug-like characteristics which could result in the development of an oral treatment for inflammatory conditions.
Asunto(s)
Amidas/síntesis química , Diseño de Fármacos , Inhibidores de Proteínas Quinasas/síntesis química , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidores , Adenosina Trifosfato/metabolismo , Sitio Alostérico , Amidas/química , Amidas/farmacocinética , Amidas/farmacología , Animales , Sitios de Unión , Células Cultivadas , Cristalografía por Rayos X , Humanos , Lipopolisacáridos/farmacología , Modelos Moleculares , Estructura Molecular , Monocitos/citología , Monocitos/efectos de los fármacos , Fosforilación/efectos de los fármacos , Unión Proteica , Conformación Proteica , Inhibidores de Proteínas Quinasas/farmacocinética , Inhibidores de Proteínas Quinasas/farmacología , Ratas , Relación Estructura-Actividad , Factor de Necrosis Tumoral alfa/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
We describe a general method for the mimicry of one face of an alpha-helix based on a terphenyl scaffold that spatially projects functionality in a manner similar to that of two turns of an alpha-helix. The synthetic scaffold reduces the flexibility and molecular weight of the mimicked protein secondary structure. We have applied this design to the development of antagonists of the alpha-helix binding protein Bcl-x(L). Using a sequential synthetic strategy, we have prepared a library of terphenyl derivatives to mimic the helical region of the Bak BH3 domain that binds Bcl-x(L). Fluorescence polarization assays were carried out to evaluate the ability of terphenyl derivatives to displace the Bcl-x(L)-bound Bak peptide. Terphenyl 14 exhibited good in vitro affinity with a K(i) value of 0.114 muM. These terphenyl derivatives were more selective at disrupting the Bcl-x(L)/Bak over the HDM2/p53 interaction, which involves binding of the N-terminal alpha-helix of p53 to HDM2. Structural studies using NMR spectroscopy and computer-aided docking simulations suggested that the helix binding area on the surface of Bcl-x(L) is the target for the synthetic ligands. Treatment of human embryonic kidney 293 (HEK293) cells with terphenyl derivatives resulted in the disruption of the binding of Bcl-x(L) to Bax in intact cells.
Asunto(s)
Proteínas de la Membrana/química , Proteínas Proto-Oncogénicas c-bcl-2/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-bcl-2/química , Compuestos de Terfenilo/química , Compuestos de Terfenilo/farmacología , Materiales Biomiméticos/síntesis química , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacología , Línea Celular , Cristalografía por Rayos X , Polarización de Fluorescencia , Humanos , Cinética , Proteínas de la Membrana/antagonistas & inhibidores , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/farmacología , Modelos Moleculares , Peso Molecular , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Fragmentos de Péptidos/farmacología , Estructura Secundaria de Proteína , Proteínas Proto-Oncogénicas/química , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas/farmacología , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/farmacología , Relación Estructura-Actividad , Compuestos de Terfenilo/síntesis química , Proteína Destructora del Antagonista Homólogo bcl-2 , Proteína bcl-XRESUMEN
The design of synthetic agents to disrupt protein-protein interactions has received relatively little attention in recent years. In this review we describe strategies for targeting different types of protein surfaces using mimetics of protein secondary or tertiary structure. In this way strong and selective binding to a protein surface has be achieved and disruption of clinically important protein-protein interactions has been demonstrated in models of human disease.
Asunto(s)
Bioquímica/métodos , Proteínas/química , Proteínas/metabolismo , Secuencia de Aminoácidos , Quimotripsina/antagonistas & inhibidores , Quimotripsina/efectos de los fármacos , Quimotripsina/metabolismo , Citocromo-c Peroxidasa/química , Citocromo-c Peroxidasa/efectos de los fármacos , Citocromo-c Peroxidasa/metabolismo , Citocromos c/química , Citocromos c/efectos de los fármacos , Citocromos c/metabolismo , Imitación Molecular , Datos de Secuencia Molecular , Compuestos Orgánicos/química , Compuestos Orgánicos/metabolismo , Compuestos Orgánicos/farmacología , Factor de Crecimiento Derivado de Plaquetas/química , Factor de Crecimiento Derivado de Plaquetas/metabolismo , Conformación Proteica , Proteínas/efectos de los fármacos , Receptores del Factor de Crecimiento Derivado de Plaquetas/química , Receptores del Factor de Crecimiento Derivado de Plaquetas/efectos de los fármacos , Receptores del Factor de Crecimiento Derivado de Plaquetas/metabolismoAsunto(s)
Materiales Biomiméticos/química , Etilaminas/química , Fragmentos de Péptidos/antagonistas & inhibidores , Fragmentos de Péptidos/química , Proteínas Proto-Oncogénicas c-bcl-2/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-bcl-2/química , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/química , Dimerización , Polarización de Fluorescencia , Proteínas de la Membrana/antagonistas & inhibidores , Proteínas de la Membrana/química , Proteínas de la Membrana/metabolismo , Modelos Moleculares , Fragmentos de Péptidos/metabolismo , Péptidos/química , Unión Proteica , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Relación Estructura-Actividad , Proteína Destructora del Antagonista Homólogo bcl-2 , Proteína bcl-XAsunto(s)
Diseño de Fármacos , Proteína gp41 de Envoltorio del VIH/química , Inhibidores de Fusión de VIH/química , VIH-1/metabolismo , Fusión de Membrana/efectos de los fármacos , Péptidos/química , Secuencia de Aminoácidos , Membrana Celular , Dicroismo Circular , Ensayo de Inmunoadsorción Enzimática , Proteína gp41 de Envoltorio del VIH/metabolismo , Humanos , Imitación Molecular , Datos de Secuencia MolecularRESUMEN
XTT can be metabolically reduced by mitochondrial dehydrogenase in viable cells to a water-soluble formazan product. Thus XTT has been widely used to evaluate cell viability and to screen anti-HIV agents and the cytotoxicity of these agents. The present studies demonstrated that XTT formazan derived from XTT in cell culture significantly inhibits the fusion of HIV-1-infected cells with uninfected cells. Synthetic XTT formazan effectively inhibited the replication of laboratory-adapted and primary HIV-1 isolates and cell-to-cell fusion with low cytotoxicity. It blocks the six-helix bundle formation between peptides derived from the N- and C-terminal heptad repeat regions of the gp41 ectodomain (designated N- and C-peptides, respectively). Analysis by a computer-aided docking program indicates that XTT formazan may bind to the highly conserved hydrophobic pocket on the surface of the central trimeric coiled coil of gp41. These results suggest that XTT formazan inhibits HIV-1 entry by targeting the alpha-helical coiled-coil domain of gp41. This small molecular nonpeptide antiviral compound can be used as a lead for designing more effective HIV-1 entry inhibitors targeting the fusion stage of HIV-1 infection. But because XTT formazan itself has anti-HIV-1 activity, caution should be exercised when XTT is used to evaluate HIV-1 infectivity.
Asunto(s)
Formazáns/farmacología , Infecciones por VIH/virología , VIH-1/efectos de los fármacos , VIH-1/patogenicidad , Replicación Viral/efectos de los fármacos , Animales , Sitios de Unión , Fusión Celular , Línea Celular , Supervivencia Celular , Dicroismo Circular , Formazáns/química , Formazáns/metabolismo , Proteína gp41 de Envoltorio del VIH/química , Proteína gp41 de Envoltorio del VIH/metabolismo , Humanos , Fusión de Membrana/efectos de los fármacos , Metosulfato de Metilfenazonio/farmacología , Ratones , Modelos MolecularesRESUMEN
The rational design of low-molecular weight ligands that disrupt protein-protein interactions is still a challenging goal in medicinal chemistry. Our approach to this problem involves the design of molecular scaffolds that mimic the surface functionality projected along one face of an alpha-helix. Using a terphenyl scaffold, which in a staggered conformation closely reproduces the projection of functionality on the surface of an alpha-helix, we designed mimics of the pro-apoptotic alpha-helical Bak-peptide as inhibitors of the Bak/Bcl-xL interaction. This led to the development of a potent Bcl-xL antagonist (KD = 114 nM), whose binding affinity for Bcl-xL was assessed by a fluorescence polarization assay. To determine the binding site of the developed inhibitor we used docking studies and an HSQC-NMR experiment with 15N-labeled Bcl-xL protein. These studies suggest that the inhibitor is binding in the same hydrophobic cleft as the Bak- and Bad-peptides.