RESUMEN
An NMR fragment screen for binders to the bromodomains of BRD4 identified 2-methyl-3-ketopyrroles 1 and 2. Elaboration of these fragments guided by structure-based design provided lead molecules with significant activity in a mouse tumor model. Further modifications to the methylpyrrole core provided compounds with improved properties and enhanced activity in a mouse model of multiple myeloma.
Asunto(s)
Antineoplásicos/química , Proteínas Nucleares/antagonistas & inhibidores , Pirroles/química , Factores de Transcripción/antagonistas & inhibidores , Animales , Antineoplásicos/síntesis química , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapéutico , Sitios de Unión , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Cristalografía por Rayos X , Diseño de Fármacos , Semivida , Humanos , Ratones , Simulación de Dinámica Molecular , Mieloma Múltiple/tratamiento farmacológico , Proteínas Nucleares/metabolismo , Pirroles/síntesis química , Pirroles/farmacocinética , Pirroles/uso terapéutico , Relación Estructura-Actividad , Factores de Transcripción/metabolismo , Trasplante HeterólogoRESUMEN
This study describes the synthesis and characterization of five conjugates of poly(ethylene glycol) modified polyethylenimine (PEG-PEIs) coupled in two different synthesis routes to a nonpeptidic pentacyclic RDG-mimetic for integrin receptor-targeted gene delivery. Synthesis of this panel of different conjugates allowed for systematic analysis of structure-activity relationships. Conjugates were therefore characterized regarding molecular composition, DNA condensation, size, and zeta potential of self-assembled polyplexes. In vitro characterization included investigation of blood compatibility, binding affinity to receptor-positive and receptor-negative cells measured by flow cytometry, cellular uptake quantified by scintillation counting, and efficiency and specificity of transfection assayed by reporter gene expression. In a first synthetic approach, low molecular weight PEI (LMW-PEI) was PEGylated using a heterobifunctional PEG linker and coupling of the RGD-mimetic was achieved at the distal end of PEG chains. In a second synthesis route, the RGD-mimetic was directly coupled to AB-block-copolymers of PEI (25 kDa) and PEG (30 kDa). Interactions of RGD-PEG-LMW-PEI conjugates with DNA were strongly impaired, whereas PEG-PEI-RGD conjugates were more promising candidates due to their physicochemical properties and higher receptor specificity. The binding, uptake, and transfection efficiency in receptor-positive cells was strongly increased upon conjugation of the RGD-mimetic to AB-block-copolymers of PEG-PEI and depended on the degree of peptide substitution. The conjugates of PEG-PEI AB-block-copolymers with low ligand density of the RGD-mimetic appear to be promising candidates for in vivo cancer gene therapy.
Asunto(s)
Materiales Biomiméticos/química , Materiales Biomiméticos/metabolismo , Técnicas de Transferencia de Gen , Integrina alfaVbeta3/metabolismo , Oligopéptidos/química , Polietilenglicoles/química , Polietileneimina/química , Materiales Biocompatibles/síntesis química , Materiales Biocompatibles/química , Materiales Biocompatibles/metabolismo , Materiales Biomiméticos/síntesis química , Línea Celular Tumoral , ADN/metabolismo , Regulación de la Expresión Génica , Humanos , Ligandos , Maleimidas/química , Propionatos/química , Compuestos de Sulfhidrilo/química , TransfecciónRESUMEN
Matrix metalloproteinases (MMPs) have been implicated in several pathologies. At Abbott Laboratories, the matrix metalloproteinases inhibitor drug discovery program has focused on the discovery of a potent, selective, orally bioavailable MMP inhibitor for the treatment of cancer. The program evolved from early succinate-based inhibitors to utilizing in-house technology such as SAR by NMR to develop a novel class of biaryl hydroxamate MMP inhibitors. The metabolic instability of the biaryl hydroxamates led to the discovery of a new class of N-formylhydroxylamine (retrohydroxamate) biaryl ethers, exemplified by ABT-770 (16). Toxicity issues with this pre-clinical candidate led to the discovery of another novel class of retrohydroxamate MMP inhibitors, the phenoxyphenyl sulfones such as ABT-518 (19j). ABT-518 is a potent, orally bioavailable, selective inhibitor of MMP-2 and 9 over MMP-1 that has been evaluated in Phase I clinical trials in cancer patients.
Asunto(s)
Industria Farmacéutica , Inhibidores de la Metaloproteinasa de la Matriz , Inhibidores de Proteasas/síntesis química , Inhibidores de Proteasas/farmacología , Animales , Diseño de Fármacos , Humanos , Espectroscopía de Resonancia Magnética , Relación Estructura-ActividadRESUMEN
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.
Asunto(s)
Inhibidores Enzimáticos/farmacología , Compuestos Heterocíclicos/farmacología , Inhibidores de Histona Desacetilasas , Cetonas/farmacología , Inhibidores Enzimáticos/química , Cetonas/química , Cinética , Relación Estructura-ActividadRESUMEN
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
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 novel series of sulfone N-formylhydroxylamines (retrohydroxamates) have been investigated as matrix metalloproteinases (MMP) inhibitors. The substitution of the ether linkage of ABT-770 (5) with a sulfone group 13a led to a substantial increase in activity against MMP-9 but was accompanied by a loss of selectivity for inhibition of MMP-2 and -9 over MMP-1 and diminished oral exposure. Replacement of the biphenyl P1' substituent with a phenoxyphenyl group provided compounds that are highly selective for inhibition of MMP-2 and -9 over MMP-1. Optimization of the substituent adjacent to the retrohydroxamate center in this series led to the clinical candidate ABT-518 (6), a highly potent, selective, orally bioavailable MMP inhibitor that has been shown to significantly inhibit tumor growth in animal cancer models.