RESUMEN
Herein we disclose SAR studies that led to a series of isoindoline ureas which we recently reported were first-in-class, non-substrate nicotinamide phosphoribosyltransferase (NAMPT) inhibitors. Modification of the isoindoline and/or the terminal functionality of screening hit 5 provided inhibitors such as 52 and 58 with nanomolar antiproliferative activity and preclinical pharmacokinetics properties which enabled potent antitumor activity when dosed orally in mouse xenograft models. X-ray crystal structures of two inhibitors bound in the NAMPT active-site are discussed.
Asunto(s)
Antineoplásicos/química , Antineoplásicos/farmacología , Citocinas/antagonistas & inhibidores , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Nicotinamida Fosforribosiltransferasa/antagonistas & inhibidores , Urea/análogos & derivados , Urea/farmacología , Animales , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapéutico , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Cristalografía por Rayos X , Citocinas/química , Citocinas/metabolismo , Descubrimiento de Drogas , Inhibidores Enzimáticos/farmacocinética , Inhibidores Enzimáticos/uso terapéutico , Humanos , Isoindoles/química , Isoindoles/farmacocinética , Isoindoles/farmacología , Isoindoles/uso terapéutico , Ratones , Modelos Moleculares , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Neoplasias/patología , Nicotinamida Fosforribosiltransferasa/química , Nicotinamida Fosforribosiltransferasa/metabolismo , Relación Estructura-Actividad , Urea/farmacocinética , Urea/uso terapéuticoRESUMEN
ABT-348 [1-(4-(4-amino-7-(1-(2-hydroxyethyl)-1H-pyrazol-4-yl)thieno[3,2-c]pyridin-3-yl)phenyl)-3-(3-fluorophenyl)urea] is a novel ATP-competitive multitargeted kinase inhibitor with nanomolar potency (IC(50)) for inhibiting binding and cellular autophosphorylation of Aurora B (7 and 13 nM), C (1 and 13 nM), and A (120 and 189 nM). Cellular activity against Aurora B is reflected by inhibition of phosphorylation of histone H3, induction of polyploidy, and inhibition of proliferation of a variety of leukemia, lymphoma, and solid tumor cell lines (IC(50) = 0.3-21 nM). In vivo inhibition of Aurora B was confirmed in an engrafted leukemia model by observing a decrease in phosphorylation of histone H3 that persisted in a dose-dependent manner for 8 h and correlated with plasma concentration of ABT-348. Evaluation of ABT-348 across a panel of 128 kinases revealed additional potent binding activity (K(i) < 30 nM) against vascular endothelial growth factor receptor (VEGFR)/platelet-derived growth factor receptor (PDGFR) families and the Src family of cytoplasmic tyrosine kinases. VEGFR/PDGFR binding activity correlated with inhibition of autophosphorylation in cells and inhibition of vascular endothelial growth factor (VEGF)-stimulated endothelial cell proliferation (IC(50) ≤ 0.3 nM). Evidence of on-target activity in vivo was provided by the potency for blocking VEGF-mediated vascular permeability and inducing plasma placental growth factor. Activity against the Src kinase family was evident in antiproliferative activity against BCR-ABL chronic myeloid leukemia cells and cells expressing the gleevec-resistant BCR-ABL T315I mutation. On the basis of its unique spectrum of activity, ABT-348 was evaluated and found effective in representative solid tumor [HT1080 and pancreatic carcinoma (MiaPaCa), tumor stasis] and hematological malignancy (RS4;11, regression) xenografts. These results provide the rationale for clinical assessment of ABT-348 as a therapeutic agent in the treatment of cancer.
Asunto(s)
Aminopiridinas/farmacología , Antineoplásicos/farmacología , Compuestos de Fenilurea/farmacología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Receptores del Factor de Crecimiento Derivado de Plaquetas/antagonistas & inhibidores , Receptores de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Familia-src Quinasas/antagonistas & inhibidores , Aminopiridinas/química , Aminopiridinas/farmacocinética , Aminopiridinas/uso terapéutico , Animales , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapéutico , Aurora Quinasa B , Aurora Quinasas , Línea Celular Tumoral , Relación Dosis-Respuesta a Droga , Femenino , Histonas/antagonistas & inhibidores , Células Endoteliales de la Vena Umbilical Humana , Humanos , Leucemia Experimental/tratamiento farmacológico , Leucemia Experimental/enzimología , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones SCID , Estructura Molecular , Células 3T3 NIH , Compuestos de Fenilurea/química , Compuestos de Fenilurea/farmacocinética , Compuestos de Fenilurea/uso terapéutico , Factores de Tiempo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
In an effort to identify kinase inhibitors with dual KDR/Aurora B activity and improved aqueous solubility compared to the Abbott dual inhibitor ABT-348, a series of novel pyrazole pyrimidines structurally related to kinase inhibitor AS703569 were prepared. SAR work provided analogs with significant cellular activity, measureable aqueous solubility and moderate antitumor activity in a mouse tumor model after weekly ip dosing. Unfortunately these compounds were pan-kinase inhibitors that suffered from narrow therapeutic indices which prohibited their use as antitumor agents.
Asunto(s)
Inhibidores de Proteínas Quinasas/química , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Pirazoles/química , Pirimidinas/química , Receptor 2 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Aminación , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Aurora Quinasa B , Aurora Quinasas , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Humanos , Ratones , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/enzimología , Modelos Moleculares , Estructura Molecular , Pirimidinas/farmacología , Relación Estructura-Actividad , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
In an effort to identify multi-targeted kinase inhibitors with a novel spectrum of kinase activity, a screen of Abbott proprietary KDR inhibitors against a broad panel of kinases was conducted and revealed a series of thienopyridine ureas with promising activity against the Aurora kinases. Modification of the diphenyl urea and C7 moiety of these compounds provided potent inhibitors with good pharmacokinetic profiles that were efficacious in mouse tumor models after oral dosing. Compound 2 (ABT-348) of this series is currently undergoing Phase I clinical trials in solid and hematological cancer populations.
Asunto(s)
Inhibidores de Proteínas Quinasas/farmacología , Piridinas/farmacología , Urea/farmacología , Animales , Antineoplásicos/química , Línea Celular Tumoral , Humanos , Ratones , Inhibidores de Proteínas Quinasas/química , Factor A de Crecimiento Endotelial VascularRESUMEN
Herein we describe the discovery of A-1331852, a first-in-class orally active BCL-XL inhibitor that selectively and potently induces apoptosis in BCL-XL-dependent tumor cells. This molecule was generated by re-engineering our previously reported BCL-XL inhibitor A-1155463 using structure-based drug design. Key design elements included rigidification of the A-1155463 pharmacophore and introduction of sp3-rich moieties capable of generating highly productive interactions within the key P4 pocket of BCL-XL. A-1331852 has since been used as a critical tool molecule for further exploring BCL-2 family protein biology, while also representing an attractive entry into a drug discovery program.
RESUMEN
A series of novel thienopyrimidine-based receptor tyrosine kinase inhibitors has been discovered. Investigation of structure-activity relationships at the 5- and 6-positions of the thienopyrimidine nucleus led to a series of N,N'-diaryl ureas that potently inhibit all of the vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) receptor tyrosine kinases. A kinase insert domain-containing receptor (KDR) homology model suggests that these compounds bind to the "inactive conformation" of the enzyme with the urea portion extending into the back hydrophobic pocket adjacent to the adenosine 5'-triphosphate (ATP) binding site. A number of compounds have been identified as displaying excellent in vivo potency. In particular, compounds 28 and 76 possess favorable pharmacokinetic (PK) profiles and demonstrate potent antitumor efficacy against the HT1080 human fibrosarcoma xenograft tumor growth model (tumor growth inhibition (TGI) = 75% at 25 mg/kg.day, per os (po)).
Asunto(s)
Antineoplásicos/síntesis química , Pirimidinas/síntesis química , Receptores del Factor de Crecimiento Derivado de Plaquetas/antagonistas & inhibidores , Urea/análogos & derivados , Urea/síntesis química , Receptor 2 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Adenosina Trifosfato/química , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Edema/inducido químicamente , Edema/patología , Estradiol , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones SCID , Modelos Moleculares , Células 3T3 NIH , Fosforilación , Pirimidinas/química , Pirimidinas/farmacología , Relación Estructura-Actividad , Urea/química , Urea/farmacología , Útero/efectos de los fármacos , Útero/patología , Receptor 2 de Factores de Crecimiento Endotelial Vascular/química , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Histone deacetylases (HDACs) are a family of enzymes involved in transcription regulation. HDACs are known to play key roles in the regulation of cell proliferation; consequently, inhibition of HDACs has become an interesting approach for anti-cancer therapy. However, expression of mammalian HDACs has proven to be difficult. All attempts to express these HDACs in E.coli, Pichia and baculovirus systems were unsuccessful. Here we present the stable expression of human recombinant His-tagged HDAC1 and HDAC3 in mammalian cells. Full-length human genes for HDAC1 and HDAC3 were cloned into the pcDNA 3.1 vector containing a N-terminal His-tag with an enterokinase cleavage site. Recombinant HDAC enzyme activity was only detected after nickel affinity purification due to high activity of endogenous HDACs; and removal of the His-tag increased activity 2-4 fold. Western blots demonstrated the nickel affinity purified rhHDAC1 preparation also contained endogenous HDAC2 and HDAC3; likewise, rhHDAC3 preparation contained endogenous HDAC1 and HDAC2. Therefore, the active HDAC preparation is actually a multi-protein and a multi-HDAC containing complex. This provides one explanation for the similar IC50 values exhibited by SAHA and MS-275 against nuclear HDACs and rhHDAC1 and 3 preparations. These results demonstrate that recombinant forms of the HDACs can be over-expressed in mammalian cells, isolated as active multi-protein complexes that contain multiple HDAC enzymes, and caution must be used when determining HDAC inhibitor in vitro selectivity.
Asunto(s)
Regulación Enzimológica de la Expresión Génica , Histona Desacetilasas/biosíntesis , Complejos Multienzimáticos/biosíntesis , Proteínas Recombinantes de Fusión/biosíntesis , Western Blotting , División Celular , Clonación Molecular , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/farmacología , Células HeLa , Histona Desacetilasa 1 , Histona Desacetilasas/genética , Histona Desacetilasas/farmacología , Humanos , Complejos Multienzimáticos/genética , Complejos Multienzimáticos/farmacología , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/farmacología , Especificidad por Sustrato , TransfecciónRESUMEN
7-Aminopyrazolo[1,5- a]pyrimidine urea receptor tyrosine kinase inhibitors have been discovered. Investigation of structure-activity relationships of the pyrazolo[1,5- a]pyrimidine nucleus led to a series of 6-(4- N, N'-diphenyl)ureas that potently inhibited a panel of vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor (PDGFR) kinases. Several of these compounds, such as 34a, are potent inhibitors of kinase insert domain-containing receptor tyrosine kinase (KDR) both enzymatically (<10 nM) and cellularly (<10 nM). In addition, compound 34a possesses a favorable pharmacokinetic profile and demonstrates efficacy in the estradiol-induced murine uterine edema (UE) model (ED 50 = 1.4 mg/kg).
Asunto(s)
Compuestos de Fenilurea/síntesis química , Compuestos de Fenilurea/farmacología , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacología , Pirazoles/síntesis química , Pirazoles/farmacología , Pirimidinas/síntesis química , Pirimidinas/farmacología , Proteínas Tirosina Quinasas Receptoras/antagonistas & inhibidores , Proteínas Tirosina Quinasas Receptoras/metabolismo , Animales , Edema/tratamiento farmacológico , Edema/enzimología , Femenino , Masculino , Ratones , Modelos Moleculares , Estructura Molecular , Compuestos de Fenilurea/química , Compuestos de Fenilurea/uso terapéutico , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/uso terapéutico , Pirazoles/química , Pirazoles/uso terapéutico , Pirimidinas/química , Pirimidinas/uso terapéutico , Proteínas Tirosina Quinasas Receptoras/química , Relación Estructura-Actividad , Urea/química , Enfermedades Uterinas/tratamiento farmacológico , Enfermedades Uterinas/enzimologíaRESUMEN
A series of non-nucleoside adenosine kinase (AK) inhibitors is reported. These inhibitors originated from the modification of 5-(3-bromophenyl)-7-(6-morpholin-4-ylpyridin-3-yl)pyrido[2,3-d]pyrimidin-4-ylamine (ABT-702). The identification of a linker that would approximate the spatial arrangement found between the pyrimidine ring and the aryl group at C(7) in ABT-702 was a key element in this modification. A search of potential linkers led to the discovery of an acetylene moiety as a suitable scaffold. It was hypothesized that the aryl acetylenes, ABT-702, and adenosine bound to the active site of AK (closed form) in a similar manner with respect to the orientation of the heterocyclic base. Although potent acetylene analogs were discovered based on this assumption, an X-ray crystal structure of 5-(4-dimethylaminophenyl)-6-(6-morpholin-4-ylpyridin-3-ylethynyl)pyrimidin-4-ylamine (16a) revealed a binding orientation contrary to adenosine. In addition, this compound bound tightly to a unique open conformation of AK. The structure-activity relationships and unique ligand orientation and protein conformation are discussed.
Asunto(s)
Adenosina Quinasa/antagonistas & inhibidores , Pirimidinas/química , Pirimidinas/farmacología , Adenosina Quinasa/química , Animales , Sitios de Unión , Cristalografía por Rayos X , Concentración 50 Inhibidora , Ratones , Morfolinas , Unión Proteica , Conformación Proteica , Pirimidinas/síntesis química , Ratas , Ratas Sprague-Dawley , Relación Estructura-ActividadRESUMEN
A series of substituted thienopyridine ureas was prepared and evaluated for enzymatic and cellular inhibition of KDR kinase activity. Several of these analogs, such as 2, are potent inhibitors of KDR (<10 nM) in both enzymatic and cellular assays. Further characterization of inhibitor 2 indicated that this analog possessed excellent in vivo potency (ED50 2.1 mg/kg) as measured in an estradiol-induced mouse uterine edema model.
Asunto(s)
Piridinas/síntesis química , Urea/síntesis química , Receptor 2 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Animales , Modelos Animales de Enfermedad , Edema/inducido químicamente , Estradiol , Femenino , Ratones , Modelos Moleculares , Piridinas/farmacología , Relación Estructura-Actividad , Urea/química , Urea/farmacología , Enfermedades Uterinas/patologíaRESUMEN
4-Amino-5,7-disubstituted pyridopyrimidines are potent, non-nucleoside inhibitors of adenosine kinase (AK). We recently identified a potent, orally efficacious analog, 4 containing a 7-pyridylmorpholine substituted ring system as the key structural element of this template. In this report, we disclose the pharmacologic effects of five- and six-membered heterocyclic ring replacements for the pyridine ring in 4. These replacements were found to have interesting effects on in vivo efficacy and genotoxicity as well as in vitro potency. We discovered that the nitrogen in the heterocyclic ring at C(7) is important for the modulation of mutagenic side effects (Ames assay).
Asunto(s)
Adenosina Quinasa/antagonistas & inhibidores , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Morfolinas/farmacología , Pirimidinas/farmacología , Animales , Línea Celular , Espectroscopía de Resonancia Magnética , Masculino , Espectrometría de Masas , Morfolinas/química , Pirimidinas/química , Ratas , Ratas Sprague-Dawley , Relación Estructura-ActividadRESUMEN
We have previously used trisubstituted cyclopropanes as peptide replacements to induce conformational constraints in known pseudopeptide inhibitors of a number of important enzymes. Cyclopropane-derived peptide mimics are novel in that they are among the few replacements that locally orient the peptide backbone and the amino acid side chain in a predefined manner. Although these dipeptide isosteres have been employed to orient amino acid side chains mimicking the gauche(-) conformation of chi(1)-space, their ability to project the side chains into an anti orientation has not been evaluated. As a first step toward this goal, the conformationally constrained pseudopeptides 8 and 10 and their corresponding flexible analogues 9 and 11 were prepared and tested as inhibitors of matrix metalloproteinases (MMPs). These compounds are analogues of 4 and 5, which were known to be potent MMP inhibitors. The anti orientations of the isopropyl side chain in 8 and the aromatic ring in 10 relative to the peptide backbone substituents on the cyclopropane were predicted to correspond to the known orientations of the P1' and P2' side chains of 5 when bound to MMPs. Hence, 8 and 10 were designed explicitly to probe topological features of the S1' or the S2' binding pockets of the MMPs. They were also designed to explore the importance of the P1'-P2' amide group, which is known to form highly conserved hydrogen bonds in several MMP-inhibitor complexes, and the viability of introducing a retro amide linkage between P2' and P3'. Pseudopeptides 8 and 9 were found to be weak competitive inhibitors of a series of MMPs. Any entropically favorable conformational constraints that were induced by the cyclopropane in 8 were thus overwhelmed by the loss of the hydrogen bonding capability associated with the P1'-P2' amide group. On the other hand, compounds 10 and 11, which contain a P2'-P3' retro amide group, were modest competitive inhibitors of a series of MMPs. The results obtained for 10 and 11 suggest that there may be a loss of hydrogen bonding capability associated with introducing the P2'-P3' retro amide group. However, because the conformationally constrained pseudopeptide 10 was significantly more potent than its flexible analogue 11, trisubstituted cyclopropanes related to 3 may serve as useful rigid dipeptide replacements in some biologically active pseudopeptides.
Asunto(s)
Ciclopropanos/química , Diseño de Fármacos , Inhibidores de la Metaloproteinasa de la Matriz , Imitación Molecular , Péptidos , Inhibidores de Proteasas/síntesis química , Secuencia de Aminoácidos , Sitios de Unión , Técnicas Químicas Combinatorias , Evaluación Preclínica de Medicamentos , Concentración 50 Inhibidora , Modelos Moleculares , Estructura Molecular , Oxidación-Reducción , Péptidos/síntesis química , Péptidos/química , Péptidos/farmacología , Inhibidores de Proteasas/química , Inhibidores de Proteasas/farmacología , Análisis Espectral , Relación Estructura-Actividad , Especificidad por SustratoRESUMEN
Trifluoromethyl ketones were found to be inhibitors of histone deacetylases (HDACs). Optimization of this series led to the identification of submicromolar inhibitors such as 20 that demonstrated antiproliferative effects against the HT1080 and MDA 435 cell lines.
Asunto(s)
Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Inhibidores de Histona Desacetilasas , Cetonas/química , Cetonas/farmacología , Acetilación , Western Blotting , Neoplasias de la Mama/metabolismo , Ciclo Celular/efectos de los fármacos , Fibrosarcoma/metabolismo , Histonas/metabolismo , Humanos , Hidrocarburos Fluorados/química , Hidrocarburos Fluorados/farmacología , Relación Estructura-Actividad , Células Tumorales CultivadasRESUMEN
A series of succinimide hydroxamic acids was prepared and evaluated in vitro for HDAC inhibition and tumor cell antiproliferation. While the original macrocyclic analogue 6 was quite potent in both assays, several appropriately substituted non-macrocyclic succinimides, such as 23, were equipotent.
Asunto(s)
Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Inhibidores de Histona Desacetilasas , Ácidos Hidroxámicos/síntesis química , Ácidos Hidroxámicos/farmacología , Succinimidas/síntesis química , Succinimidas/farmacología , Aminoácidos/química , Sitios de Unión/efectos de los fármacos , Cristalografía por Rayos X , Histona Desacetilasas/química , Histona Desacetilasas/metabolismo , Humanos , Ácidos Hidroxámicos/metabolismo , Indicadores y Reactivos , Células K562 , Conformación Molecular , Relación Estructura-Actividad , Succinimidas/metabolismo , Células Tumorales CultivadasRESUMEN
Alpha-keto ester and amides were found to be potent inhibitors of histone deacetylase. Nanomolar inhibitors against the isolated enzyme and sub-micromolar inhibitors of cellular proliferation were obtained. The alpha-keto amide 30 also exhibited significant anti-tumor effects in an in vivo tumor model.
Asunto(s)
Amidas/química , Amidas/farmacología , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Inhibidores de Histona Desacetilasas , Animales , Línea Celular Tumoral , Histona Desacetilasas/metabolismo , Humanos , Ratones , Ensayos Antitumor por Modelo de Xenoinjerto/métodosRESUMEN
A series of substituted isoindolinone ureas was prepared and evaluated for enzymatic and cellular inhibition of KDR kinase activity. Several of these analogs, such as 14c, are potent inhibitors of KDR both enzymatically (< 50 nM) and cellularly < or = 100 nM). A 3D KDR/CDK2/MAP kinase overlay model with several structurally related tyrosine kinase inhibitors was used to predict the binding interactions of the isoindolinone ureas with the KDR active site.
Asunto(s)
Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Indoles/química , Urea/química , Receptor 2 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Animales , Humanos , Indoles/farmacología , Ratones , Células 3T3 NIH , Urea/farmacología , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Several heterocyclic ketones were investigated as potential inhibitors of histone deacetylase. Nanomolar inhibitors such as 22 and 25 were obtained, the anti-proliferative activity of which were shown to be mediated by HDAC inhibition.