RESUMO
A series of hydroxamic acids linked by different lengths to a chiral imidazo-ketopiperazine scaffold were synthesized. The compounds with linker lengths of 6 and 7 carbon atoms were the most potent in histone deacetylase (HDAC) inhibition, and were specific submicromolar inhibitors of the HDAC1, HDAC6 and HDAC8 isoforms. A docking model for the binding mode predicts binding of the hydroxamic acid to the active site zinc cation and additional interactions between the imidazo-ketopiperazine and the enzyme rim. The compounds were micromolar inhibitors of the MV4-11, THP-1 and U937 cancer cell lines. Increased levels of histone H3 and tubulin acetylation support a cellular mechanism of action through HDAC inhibition.This article is part of a discussion meeting issue 'Frontiers in epigenetic chemical biology'.
Assuntos
Histona Desacetilase 1/antagonistas & inibidores , Desacetilase 6 de Histona/antagonistas & inibidores , Inibidores de Histona Desacetilases/farmacologia , Ácidos Hidroxâmicos/farmacologia , Proteínas Repressoras/antagonistas & inibidores , Acetilação , Histona Desacetilase 1/química , Desacetilase 6 de Histona/química , Inibidores de Histona Desacetilases/química , Histona Desacetilases/química , Humanos , Ácidos Hidroxâmicos/química , Simulação de Acoplamento Molecular , Isoformas de Proteínas , Proteínas Repressoras/química , Estereoisomerismo , Relação Estrutura-Atividade , Células THP-1 , Células U937RESUMO
Histone deacetylase 8 (HDAC8), a unique class I zinc-dependent HDAC, is an emerging target in cancer and other diseases. Its substrate repertoire extends beyond histones to many nonhistone proteins. Besides being a deacetylase, HDAC8 also mediates signaling via scaffolding functions. Aberrant expression or deregulated interactions with transcription factors are critical in HDAC8-dependent cancers. Many potent HDAC8-selective inhibitors with cellular activity and anticancer effects have been reported. We present HDAC8 as a druggable target and discuss inhibitors of different chemical scaffolds with cellular effects. Furthermore, we review HDAC8 activators that revert activity of mutant enzymes. Isotype-selective HDAC8 targeting in patients with HDAC8-relevant cancers is challenging, however, is promising to avoid adverse side effects as observed with pan-HDAC inhibitors.
Assuntos
Antineoplásicos/farmacologia , Neoplasias/tratamento farmacológico , Doenças Neurodegenerativas/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Proteínas Repressoras/antagonistas & inibidores , Antineoplásicos/química , Histona Desacetilases/metabolismo , Humanos , Neoplasias/metabolismo , Doenças Neurodegenerativas/metabolismo , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/química , Proteínas Repressoras/metabolismoRESUMO
Histone deacetylase 8 (HDAC8) is a class I histone deacetylase implicated as a therapeutic target in various diseases, including cancer, X-linked intellectual disability, and parasitic infections. It is a structurally well-characterized enzyme that also deacetylates nonhistone proteins. In cancer, HDAC8 is a major 'epigenetic player' that is linked to deregulated expression or interaction with transcription factors critical to tumorigenesis. In the parasite Schistosoma mansoni and in viral infections, HDAC8 is a novel target to subdue infection. The current challenge remains in the development of potent selective inhibitors that would specifically target HDAC8 with fewer adverse effects compared with pan-HDAC inhibitors. Here, we review HDAC8 as a drug target and discuss inhibitors with respect to their structural features and therapeutic interventions.
Assuntos
Ativadores de Enzimas/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Proteínas Repressoras/antagonistas & inibidores , Animais , Síndrome de Cornélia de Lange/tratamento farmacológico , Síndrome de Cornélia de Lange/enzimologia , Ativadores de Enzimas/química , Inibidores Enzimáticos/química , Histona Desacetilases/química , Histona Desacetilases/genética , Humanos , Modelos Moleculares , Estrutura Molecular , Mutação , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Ligação Proteica , Proteínas Repressoras/química , Proteínas Repressoras/genética , Schistosoma/efeitos dos fármacos , Schistosoma/enzimologia , Esquistossomose/tratamento farmacológico , Relação Estrutura-AtividadeAssuntos
Amidas/química , Ácidos Fosfóricos/química , Polietilenoglicóis/química , Apoptose , Humanos , Células Jurkat , Peptídeos , ProteóliseRESUMO
Multivalent peptide-oligosaccharide conjugates were prepared and used to investigate the multivalency effect concerning the activity of Bid-BH3 peptides in live cells. Dextran oligosaccharides were carboxyethylated selectively in the 2-position of the carbohydrate units and activated for the ligation of N-terminally cysteinylated peptides. Ligation through maleimide coupling was found to be superior to the native chemical ligation protocol. Monomeric Bid-BH3 peptides were virtually inactive, whereas pentameric peptide conjugates induced apoptosis up to 20-fold stronger at identical peptide concentrations. Comparison of lowly multivalent and highly multivalent peptide dextrans proved a multivalency effect in life cells which was specific for the BH3 peptide sequence.
Assuntos
Apoptose/efeitos dos fármacos , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/química , Dextranos/química , Fragmentos de Peptídeos/química , Proteínas Proto-Oncogênicas/química , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Dextranos/síntese química , Dextranos/farmacologia , Relação Dose-Resposta a Droga , Eletroporação , Células HeLa , Humanos , Células Jurkat , Maleimidas/química , Microscopia Confocal , Oligopeptídeos/química , Fragmentos de Peptídeos/administração & dosagem , Fragmentos de Peptídeos/síntese química , Fragmentos de Peptídeos/farmacologia , Proteínas Proto-Oncogênicas/administração & dosagem , Proteínas Proto-Oncogênicas/síntese química , Proteínas Proto-Oncogênicas/farmacologia , Espectrometria de FluorescênciaRESUMO
Here, we demonstrate that coupling to N-hydroxypropyl methacrylamide (HPMA) copolymer greatly enhances the activity of apoptosis-inducing peptides inside cells. Peptides corresponding to the BH3 domain of Bid were coupled to a thioester-activated HPMA (28.5 kDa) via native chemical ligation in a simple one-pot synthesis. Peptides and polymer conjugates were introduced into cells either by electroporation or by conjugation to the cell-penetrating peptide nona-arginine. The molecular basis of the increased activity is elucidated in detail. Loading efficiency and intracellular residence time were assessed by confocal microscopy. Fluorescence correlation spectroscopy was used as a separation-free analytical technique to determine proteolytic degradation in crude cell lysates. HPMA conjugation strongly increased the half-life of the peptides in crude cell lysates and inside cells, revealing proteolytic protection as the basis for higher activity.