RESUMEN
The introduction of side chains bearing epoxide motifs into the molecular scaffold of kenpaullone and 9-trifluoromethylpaullone led to improved antiproliferative activity of the novel derivatives for human tumor cell lines. The syntheses were accomplished applying Stille coupling for the introduction of unsaturated side chains into the 2-position of the paullones and subsequently employing a hydrogen peroxide/nitrile mixture for the epoxidation of C,C-double bonds.
Asunto(s)
Antineoplásicos/síntesis química , Benzazepinas/síntesis química , Compuestos Epoxi/síntesis química , Indoles/síntesis química , Antineoplásicos/farmacología , Benzazepinas/farmacología , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Compuestos Epoxi/farmacología , Humanos , Indoles/farmacología , Relación Estructura-ActividadRESUMEN
In order to perform computer-aided design of novel alsterpaullone derivatives, the vicinity of the entrance to the ATP-binding site was scanned for areas that could be useful as anchoring points for additional protein-ligand interactions. Based on the alignment of alsterpaullone in a CDK1/cyclin B homology model, substituents were attached to the 2-position of the parent scaffold to enable contacts within the identified areas. Synthesis of the designed structures revealed three derivatives (3-5) with kinase-inhibitory activity similar to alsterpaullone. The novel 2-cyanoethylalsterpaullone (7) proved to be the most potent paullone described so far, exhibiting inhibitory concentrations for CDK1/ cyclin B and GSK-3beta in the picomolar range.
Asunto(s)
Benzazepinas/química , Diseño de Fármacos , Indoles/química , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Adenosina Trifosfato/farmacología , Animales , Benzazepinas/farmacología , Sitios de Unión , Proteína Quinasa CDC2/antagonistas & inhibidores , Proteína Quinasa CDC2/química , Proteína Quinasa CDC2/metabolismo , Línea Celular , Indoles/farmacología , Concentración 50 Inhibidora , Modelos Moleculares , Conformación Molecular , Spodoptera , Relación Estructura-ActividadRESUMEN
Multiple linear regression analysis was employed in an effort to establish a quantitative structure-activity relationship model for the CDK1-inhibitory activity of a series of 9-substituted paullones. While the electronic properties of the 9-substituents proved to be of high relevance for CDK1 inhibition, both lipophilic and a steric parameters could not be included in a meaningful equation for the calculation of biological properties. The equation solely based on the electronic parameter was successfully used for the prediction of the CDK1-inhibitory activity of a small test set comprising novel paullones with sulfur-containing 9-substituents. Among these new derivatives, 2-methoxy-9-methylsulfonylpaullone proved to be superior to the standard alsterpaullone with respect to CDK1 inhibition.
Asunto(s)
Benzazepinas , Proteína Quinasa CDC2/antagonistas & inhibidores , Inhibidores Enzimáticos , Indoles , Animales , Benzazepinas/síntesis química , Benzazepinas/química , Benzazepinas/farmacología , Electrones , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Indoles/síntesis química , Indoles/química , Indoles/farmacología , Modelos Lineales , Estructura Molecular , Relación Estructura-Actividad Cuantitativa , Estrellas de Mar/enzimologíaRESUMEN
Indirubin, a bis-indole obtained from various natural sources, is responsible for the reported antileukemia activity of a Chinese Medicinal recipe, Danggui Longhui Wan. However, its molecular mechanism of action is still not well understood. In addition to inhibition of cyclin-dependent kinases and glycogen synthase kinase-3, indirubins have been reported to activate the aryl hydrocarbon receptor (AhR), a cotranscriptional factor. Here, we confirm the interaction of AhR and indirubin using a series of indirubin derivatives and show that their binding modes to AhR and to protein kinases are unrelated. As reported for other AhR ligands, binding of indirubins to AhR leads to its nuclear translocation. Furthermore, the apparent survival of AhR-/- and +/+ cells, as measured by the MTT assay, is equally sensitive to the kinase-inhibiting indirubins. Thus, the cytotoxic effects of indirubins are AhR-independent and more likely to be linked to protein kinase inhibition. In contrast, a dramatic cytostatic effect, as measured by actual cell counts and associated with a sharp G1 phase arrest, is induced by 1-methyl-indirubins, a subfamily of AhR-active but kinase-inactive indirubins. As shown for TCDD (dioxin), this effect appears to be mediated through the AhR-dependent expression of p27(KIP1). Altogether these results suggest that AhR activation, rather than kinase inhibition, is responsible for the cytostatic effects of some indirubins. In contrast, kinase inhibition, rather than AhR activation, represents the main mechanism underlying the cytotoxic properties of this class of promising antitumor molecules.
Asunto(s)
Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Inhibidores de Crecimiento/farmacología , Indoles/farmacología , Receptores de Hidrocarburo de Aril/efectos de los fármacos , Animales , Ciclo Celular/efectos de los fármacos , Proteínas de Ciclo Celular/biosíntesis , Proteínas de Ciclo Celular/genética , Línea Celular Tumoral/efectos de los fármacos , Inhibidor p27 de las Quinasas Dependientes de la Ciclina , Ensayos de Selección de Medicamentos Antitumorales , Fase G1/efectos de los fármacos , Humanos , Indoles/química , Indoles/metabolismo , Ligandos , Neoplasias Hepáticas Experimentales/patología , Ratones , Dibenzodioxinas Policloradas/metabolismo , Dibenzodioxinas Policloradas/farmacología , Unión Proteica , Transporte de Proteínas/efectos de los fármacos , Receptores de Hidrocarburo de Aril/deficiencia , Receptores de Hidrocarburo de Aril/metabolismo , Relación Estructura-Actividad , Proteínas Supresoras de Tumor/biosíntesis , Proteínas Supresoras de Tumor/genéticaRESUMEN
Meridianins are brominated 3-(2-aminopyrimidine)-indoles which are purified from Aplidium meridianum, an Ascidian from the South Atlantic (South Georgia Islands). We here show that meridianins inhibit various protein kinases such as cyclin-dependent kinases, glycogen synthase kinase-3, cyclic nucleotide-dependent kinases and casein kinase 1. Meridianins prevent cell proliferation and induce apoptosis, a demonstration of their ability to enter cells and to interfere with the activity of kinases important for cell division and cell death. These results suggest that meridianins constitute a promising scaffold from which more potent and selective protein kinase inhibitors could be designed.
Asunto(s)
Aminopiridinas/aislamiento & purificación , Inhibidores Enzimáticos/aislamiento & purificación , Inhibidores Enzimáticos/farmacología , Alcaloides Indólicos/aislamiento & purificación , Inhibidores de Proteínas Quinasas , Urocordados/enzimología , Aminopiridinas/farmacología , Animales , División Celular/efectos de los fármacos , División Celular/fisiología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/química , Humanos , Alcaloides Indólicos/farmacología , RatonesRESUMEN
The CDC25 phosphatases regulate the cell division cycle by controlling the activity of cyclin-dependent kinases. While screening for inhibitors of phosphatases among natural products we repeatedly found that some polyprenyl-hydroquinones and polyprenyl-furans (furanoterpenoids) (furospongins, furospinosulins) were potent CDC25 phosphatase inhibitors. These compounds were extracted, isolated and identified independently from three sponge species (Spongia officinalis, Ircinia spinulosa, Ircinia muscarum), collected at different locations in the Mediterranean Sea. The compounds were inactive on the Ser/Thr phosphatase PP2C-alpha and on three kinases (CDK1, CDK5, GSK-3), suggesting that some potent and selective CDC25 phosphatase might be designed from these initial structures.
Asunto(s)
Ciclo Celular/efectos de los fármacos , Furanos/farmacología , Hidroquinonas/farmacología , Poríferos/química , Fosfatasas cdc25/efectos de los fármacos , Fosfatasas cdc25/farmacología , Animales , Escherichia coli , Furanos/aislamiento & purificación , Hidroquinonas/aislamiento & purificaciónRESUMEN
Pharmacological inhibitors of glycogen synthase kinase-3 (GSK-3) and cyclin-dependent kinases have a promising potential for applications against several neurodegenerative diseases such as Alzheimer's disease. Indirubins, a family of bis-indoles isolated from various natural sources, are potent inhibitors of several kinases, including GSK-3. Using the cocrystal structures of various indirubins with GSK-3beta, CDK2 and CDK5/p25, we have modeled the binding of indirubins within the ATP-binding pocket of these kinases. This modeling approach provided some insight into the molecular basis of indirubins' action and selectivity and allowed us to forecast some improvements of this family of bis-indoles as kinase inhibitors. Predicted molecules, including 6-substituted and 5,6-disubstituted indirubins, were synthesized and evaluated as CDK and GSK-3 inhibitors. Control, kinase-inactive indirubins were obtained by introduction of a methyl substitution on N1.
Asunto(s)
Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Glucógeno Sintasa Quinasa 3/antagonistas & inhibidores , Indoles/síntesis química , Oximas/síntesis química , Quinasas Ciclina-Dependientes/química , Glucógeno Sintasa Quinasa 3/química , Indoles/química , Modelos Moleculares , Oximas/química , Relación Estructura-ActividadRESUMEN
With a view to the rational design of selective GSK-3beta inhibitors, 3D-QSAR CoMSIA models were developed for the inhibition of the three serine/threonine kinases CDK1/cyclin B, CDK5/p25, and GSK-3beta by compounds from the paullone inhibitor family. The models are based on the kinase inhibition data of 52 paullone entities, which were aligned by a docking routine into the ATP-binding cleft of a CDK1/cyclin B homology model. Variation of grid spacing and column filtering were used during the optimization of the models. The predictive ability of the models was shown by a leave-one-out cross-validation and the prediction of an independent set of test compounds, which were synthesized especially for this purpose. Besides paullones with the basic indolo[3,2-d][1]benzazepine core, the test set comprised novel thieno[3',2':2,3]azepino[4,5-b]indoles, pyrido[2',3':2,3]azepino[4,5-b]indoles, and a pyrido[3',2':4,5]pyrrolo[3,2-d][1]benzazepine. The best statistical values for the CoMSIA were obtained for the CDK1-models (r(2)() = 0.929 and q(2)() = 0.699), which were clearly superior to the models for CDK5 (r(2)() = 0.874 and q(2)() = 0.652) and GSK-3 (r(2)() = 0.871 and q(2)() = 0.554).
Asunto(s)
Benzazepinas/síntesis química , Proteína Quinasa CDC2/antagonistas & inhibidores , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Indoles/síntesis química , Animales , Benzazepinas/química , Proteína Quinasa CDC2/química , Quinasa 3 Dependiente de Ciclina , Quinasa 5 Dependiente de la Ciclina , Quinasas Ciclina-Dependientes/química , Indoles/química , Modelos Moleculares , Unión Proteica , Relación Estructura-Actividad CuantitativaRESUMEN
Kenpaullone derivatives with a modified parent ring system were synthesized in order to develop kinase inhibitors with enhanced selectivity. Among the novel structures, 1-azakenpaullone was found to act as a selective GSK-3beta versus CDK1 inhibitor. The charge distribution within the 1-azakenpaullone molecule is discussed as a possible explanation for the enhanced GSK-3beta selectivity of 1-azakenpaullone compared to other paullone derivatives.
Asunto(s)
Benzazepinas/síntesis química , Inhibidores Enzimáticos/síntesis química , Glucógeno Sintasa Quinasa 3/antagonistas & inhibidores , Indoles/síntesis química , Benzazepinas/farmacología , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/farmacología , Glucógeno Sintasa Quinasa 3/metabolismo , Glucógeno Sintasa Quinasa 3 beta , Indoles/farmacologíaRESUMEN
Cyclin-dependent kinases (CDKs) regulate the cell cycle, apoptosis, neuronal functions, transcription, and exocytosis. The observation of CDK deregulations in various pathological situations suggests that CDK inhibitors may have a therapeutic value. In this article, we report on the identification of 6-phenyl[5H]pyrrolo[2,3-b]pyrazines (aloisines) as a novel potent CDK inhibitory scaffold. A selectivity study performed on 26 kinases shows that aloisine A is highly selective for CDK1/cyclin B, CDK2/cyclin A-E, CDK5/p25, and GSK-3 alpha/beta; the two latter enzymes have been implicated in Alzheimer's disease. Kinetic studies, as well as the resolution of a CDK2-aloisine cocrystal structure, demonstrate that aloisines act by competitive inhibition of ATP binding to the catalytic subunit of the kinase. As observed with all inhibitors reported so far, aloisine interacts with the ATP-binding pocket through two hydrogen bonds with backbone nitrogen and oxygen atoms of Leu 83. Aloisine inhibits cell proliferation by arresting cells in both G1 and G2.
Asunto(s)
Antineoplásicos/síntesis química , Quinasas CDC2-CDC28 , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Inhibidores Enzimáticos/síntesis química , Glucógeno Sintasa Quinasa 3/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Pirazinas/síntesis química , Adenosina Trifosfato/química , Antineoplásicos/química , Antineoplásicos/farmacología , Unión Competitiva , Proteína Quinasa CDC2/antagonistas & inhibidores , División Celular/efectos de los fármacos , Quinasa 2 Dependiente de la Ciclina , Quinasa 5 Dependiente de la Ciclina , Quinasas Ciclina-Dependientes/química , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Glucógeno Sintasa Quinasa 3/química , Humanos , Enlace de Hidrógeno , Modelos Moleculares , Conformación Molecular , Neuronas/citología , Neuronas/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/química , Pirazinas/química , Pirazinas/farmacología , Relación Estructura-Actividad , Células Tumorales CultivadasRESUMEN
Gastropod mollusks have been used for over 2500 years to produce the "Tyrian purple" dye made famous by the Phoenicians. This dye is constituted of mixed bromine-substituted indigo and indirubin isomers. Among these, the new natural product 6-bromoindirubin and its synthetic, cell-permeable derivative, 6-bromoindirubin-3'-oxime (BIO), display remarkable selective inhibition of glycogen synthase kinase-3 (GSK-3). Cocrystal structure of GSK-3beta/BIO and CDK5/p25/indirubin-3'-oxime were resolved, providing a detailed view of indirubins' interactions within the ATP binding pocket of these kinases. BIO but not 1-methyl-BIO, its kinase inactive analog, also inhibited the phosphorylation on Tyr276/216, a GSK-3alpha/beta activation site. BIO but not 1-methyl-BIO reduced beta-catenin phosphorylation on a GSK-3-specific site in cellular models. BIO but not 1-methyl-BIO closely mimicked Wnt signaling in Xenopus embryos. 6-bromoindirubins thus provide a new scaffold for the development of selective and potent pharmacological inhibitors of GSK-3.
Asunto(s)
Inhibidores Enzimáticos/aislamiento & purificación , Inhibidores Enzimáticos/farmacología , Glucógeno Sintasa Quinasa 3/antagonistas & inhibidores , Indoles/aislamiento & purificación , Indoles/farmacología , Animales , Sitios de Unión , Línea Celular , Cristalografía por Rayos X , Embrión no Mamífero/efectos de los fármacos , Embrión no Mamífero/metabolismo , Inhibidores Enzimáticos/química , Glucógeno Sintasa Quinasa 3/química , Glucógeno Sintasa Quinasa 3/metabolismo , Indoles/química , Modelos Moleculares , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Estructura Terciaria de Proteína , Proteínas Proto-Oncogénicas/metabolismo , Mariscos , Transducción de Señal/efectos de los fármacos , Especificidad por Sustrato , Proteínas Wnt , Xenopus/embriología , Xenopus/metabolismoRESUMEN
Paullones 3 and 4 with aminoalkyl side chains in 2- or 3-position were synthesized as derivatives of kenpaullone 1. Both 3 and 4 showed the characteristic CDK1-inhibitory activity of the paullones and a modest antiproliferative activity on cultured human tumor cell lines. Hence, 3 and 4 appear to be suitable tools for affinity studies directed to find additional intracellular paullone targets.
Asunto(s)
Benzazepinas/síntesis química , Antineoplásicos/síntesis química , Antineoplásicos/química , Antineoplásicos/farmacología , Benzazepinas/química , Benzazepinas/farmacología , Proteína Quinasa CDC2/antagonistas & inhibidores , Ensayos de Selección de Medicamentos Antitumorales , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Humanos , Estructura Molecular , Células Tumorales CultivadasRESUMEN
Numerous inhibitors of cyclin-dependent kinases and glycogen synthase kinase-3 (GSK-3) are being developed in view of their potential applications against cancers and neurodegenerative disorders. Among these, paullones constitute a family of potent and apparently selective cyclin-dependent kinase and GSK-3 inhibitors. However, their actual intracellular targets remain to be identified. To address this issue we have immobilized a paullone, gwennpaullone, on an agarose matrix. Extracts from various cell types and tissues were screened for proteins interacting with this matrix. This approach validated GSK-3alpha and GSK-3beta as major intracellular paullone targets and also mitochondrial, but not cytoplasmic, malate dehydrogenase (MDH). Mitochondrial MDH was indeed inhibited by micromolar concentrations of paullones. Mitochondrial MDH was the major paullone-binding protein in the parasitic protozoon Leishmania mexicana, and paullones inhibited growth of the parasite. This simple batchwise affinity chromatography approach constitutes a straightforward method for the identification of intracellular targets of this particular class of novel anti-mitotic compounds. It has revealed an unexpected target, mitochondrial MDH, the inhibition of which may participate in the pharmacological effects of paullones.