RESUMEN
CRA-024781 is a novel, broad spectrum hydroxamic acid-based inhibitor of histone deacetylase (HDAC) that shows antitumor activity in vitro and in vivo preclinically and is under evaluation in phase I clinical trials for cancer. CRA-024781 inhibited pure recombinant HDAC1 with a K(i) of 0.007 mumol/L, and also inhibited the other HDAC isozymes HDAC2, HDAC3/SMRT, HDAC6, HDAC8, and HDAC10 in the nanomolar range. Treatment of cultured tumor cell lines grown in vitro with CRA-024781 resulted in the accumulation of acetylated histone and acetylated tubulin, resulting in an inhibition of tumor cell growth and the induction of apoptosis. CRA-024781 parenterally administered to mice harboring HCT116 or DLD-1 colon tumor xenografts resulted in a statistically significant reduction in tumor growth at doses that were well tolerated as measured by body weight. Inhibition of tumor growth was accompanied by an increase in the acetylation of alpha-tubulin in peripheral blood mononuclear cells, and an alteration in the expression of many genes in the tumors, including several involved in apoptosis and cell growth. These results reveal CRA-024781 to be a novel HDAC inhibitor with potent antitumor activity.
Asunto(s)
Antineoplásicos/farmacología , Benzofuranos/farmacología , Inhibidores Enzimáticos/farmacología , Inhibidores de Histona Desacetilasas , Ácidos Hidroxámicos/farmacología , Acetilación/efectos de los fármacos , Animales , Antineoplásicos/farmacocinética , Benzofuranos/farmacocinética , Biomarcadores de Tumor , Proliferación Celular/efectos de los fármacos , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Diseño de Fármacos , Inhibidores Enzimáticos/farmacocinética , Femenino , Células HCT116 , Histona Desacetilasas/metabolismo , Histonas/metabolismo , Humanos , Ácidos Hidroxámicos/farmacocinética , Técnicas In Vitro , Ratones , Ratones Endogámicos BALB C , Poli(ADP-Ribosa) Polimerasas/metabolismo , Transcripción Genética/efectos de los fármacos , Células Tumorales CultivadasRESUMEN
CRA-026440 is a novel, broad-spectrum, hydroxamic acid-based inhibitor of histone deacetylase (HDAC) that shows antitumor and antiangiogenic activities in vitro and in vivo preclinically. CRA-026440 inhibited pure recombinant isozymes HDAC1, HDAC2, HDAC3/SMRT, HDAC6, HDAC8, and HDAC10 in the nanomolar range. Treatment of cultured tumor cell lines grown in vitro with CRA-026440 resulted in the accumulation of acetylated histone and acetylated tubulin, leading to an inhibition of tumor cell growth and the induction of apoptosis. CRA-026440 inhibited ex vivo angiogenesis in a dose-dependent manner. CRA-026440 parenterally given to mice harboring HCT116 or U937 human tumor xenografts resulted in a statistically significant reduction in tumor growth. CRA-026440, when used in combination with Avastin, achieved greater preclinical efficacy in HCT 116 colorectal tumor model. Inhibition of tumor growth was accompanied by an increase in the acetylation of alpha-tubulin in peripheral blood mononuclear cells and an alteration in the expression of many genes in the tumors, including several involved in angiogenesis, apoptosis, and cell growth. These results reveal CRA-026440 to be a novel HDAC inhibitor with potent antitumor activity.
Asunto(s)
Inhibidores de la Angiogénesis/farmacología , Antineoplásicos/farmacología , Inhibidores Enzimáticos/farmacología , Inhibidores de Histona Desacetilasas , Ácidos Hidroxámicos/farmacología , Indoles/farmacología , Neoplasias/enzimología , Acetilación , Inhibidores de la Angiogénesis/química , Inhibidores de la Angiogénesis/farmacocinética , Animales , Antineoplásicos/química , Antineoplásicos/farmacocinética , Apoptosis , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/efectos de los fármacos , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacocinética , Femenino , Expresión Génica/efectos de los fármacos , Perfilación de la Expresión Génica , Histonas/efectos de los fármacos , Humanos , Ácidos Hidroxámicos/química , Indoles/química , Ratones , Ratones Endogámicos BALB C , Neoplasias/irrigación sanguínea , Neoplasias/genética , Poli Adenosina Difosfato Ribosa/efectos adversos , Tubulina (Proteína)/efectos de los fármacos , Tubulina (Proteína)/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Beginning with the peptide sequence Cbz-Ile-Glu(OtBu)-Ala-Leu found in PSI (3), a series of vinyl sulfones (VS) were synthesized for evaluation as inhibitors of the chymotrypsin-like activity of the 20S proteasome. Variations at the key P3 position confirmed the importance of a long side chain capped with a hydrophobic group for optimal potency, consistent with a model of binding to the S3 subsite. The tert-butyl glutamic ester initially used at P3 gave plasma unstable, insoluble compounds and was replaced with the better isostere, N-beta-neopentyl asparagine. The inhibitors were shortened by replacing the N-terminal Cbz-isoleucine with a p-tosyl group without loss of potency. Small l-amino acids were used at P2, where d-substitution was not tolerated. The resulting optimized P4-P3-P2 sequence was grafted onto a novel proteasome inhibitor warhead, 2-keto-1,3,4-oxadiazoles (KOD), to produce reversible, subnanomolar proteasome inhibitors that were 1000-fold selective versus cathepsin B (CatB), cathepsin S (CatS), and trypsin-like as well as PGPH-like proteasome activity. A number of compounds in both the VS and the KOD series exhibited growth inhibitory effects against the human prostate cancer cell line PC3 at submicromolar concentrations.
Asunto(s)
Oligopéptidos/síntesis química , Oxadiazoles/síntesis química , Complejo de la Endopetidasa Proteasomal/metabolismo , Inhibidores de Proteasoma , Sulfonas/síntesis química , Compuestos de Vinilo/síntesis química , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Antineoplásicos/farmacología , Bovinos , Proliferación Celular/efectos de los fármacos , Estabilidad de Medicamentos , Humanos , Técnicas In Vitro , Modelos Moleculares , Oligopéptidos/química , Oligopéptidos/farmacología , Oxadiazoles/química , Oxadiazoles/farmacología , Complejo de la Endopetidasa Proteasomal/química , Subunidades de Proteína/antagonistas & inhibidores , Subunidades de Proteína/química , Subunidades de Proteína/metabolismo , Solubilidad , Relación Estructura-Actividad , Sulfonas/química , Sulfonas/farmacología , Compuestos de Vinilo/química , Compuestos de Vinilo/farmacologíaRESUMEN
1-Cyanopyrrolidines have previously been reported to inhibit cysteinyl cathepsins (Falgueyret, J.-P. et al., J. Med. Chem. 2001, 44, 94). In order to optimize binding interactions for a given cathepsin and simultaneously reduce interactions with the other closely related enzymes, small peptidic substituents were introduced to the 1-cyanopyrrolidine scaffold, either at the 2-position starting with proline or at the 3-position of aminopyrrolidines. The resulting novel compounds proved to be micromolar inhibitors of cathepsin B (Cat B) but nanomolar to picomolar inhibitors of cathepsins K, L, and S (Cat K, Cat L, Cat S). Several of the compounds were >20-fold selective versus the other three cathepsins. SAR trends were observed, most notably the remarkable potency of Cat L inhibitors based on the 1-cyano-D-proline scaffold. The selectivity of one such compound, the 94 picomolar Cat L inhibitor 12, was demonstrated at higher concentrations in DLD-1 cells. Although none of the compounds in the proline series that was tested proved to be submicromolar in the in vitro bone resorption assay, two Cat K inhibitors in the 3-substituted pyrrolidine series, 24 and 25 were relatively potent in that assay.
Asunto(s)
Catepsinas/antagonistas & inhibidores , Dipéptidos/síntesis química , Pirrolidinas/síntesis química , Animales , Resorción Ósea/tratamiento farmacológico , Dipéptidos/farmacología , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Ratones , Nitrilos/síntesis química , Nitrilos/farmacología , Pirrolidinas/farmacología , Relación Estructura-ActividadRESUMEN
We describe a novel diazomethylketone-containing irreversible inhibitor (BIL-DMK) which is specific for a subset of pharmaceutically important cysteine cathepsin proteases. BIL-DMK rapidly inactivates cathepsins B, F, K, L, S, and V in isolated enzyme assays and labels cathepsins in whole cells. The presence of catalytically active cathepsins B, L, and K or S was demonstrated using radioiodinated BIL-DMK in HepG2 (hepatoma), HIG82 (rabbit synoviocyte), and Ramos (B lymphoma) cell lines, respectively. The identity of each protein labeled was confirmed from the isoelectric point and molecular mass of the radioactive spots on two-dimensional gel and by comigration with each cathepsin as identified by immunoblotting. These cell lines were used to establish whole-cell enzyme occupancy assays to determine the potency of both irreversible and reversible inhibitors against each cathepsin in their native cellular lysosomal or endosomal environment. These whole-cell enzyme occupancy assays are useful to determine the cellular permeability of competing inhibitors and have the advantage of not requiring specific substrates for each cathepsin of interest.