RESUMEN
The IAPs are key regulators of the apoptotic pathways and are commonly overexpressed in many cancer cells. IAPs contain one to three BIR domains that are crucial for their inhibitory function. The pro-survival properties of XIAP come from binding of the BIR domains to the pro-apoptotic caspases. The BIR3 domain of XIAP binds and inhibits caspase 9, while the BIR2 domain binds and inhibits the terminal caspases 3 and 7. While XIAP BIR3 inhibitors have previously been reported, they also inhibit cIAP1/2 and promote the release of TNFα, potentially limiting their therapeutic utility. This paper will focus on the optimization of selective XIAP BIR2 inhibitors leading to the discovery of highly potent benzodiazepinone 36 (IC50 = 45 nM), which has high levels of selectivity over XIAP BIR3 and cIAP1 BIR2/3 and shows efficacy in a xenograft pharmacodynamic model monitoring caspase activity while not promoting the release of TNFα in vitro.
Asunto(s)
Compuestos Heterocíclicos/síntesis química , Compuestos Heterocíclicos/farmacología , Proteínas Inhibidoras de la Apoptosis/antagonistas & inhibidores , Proteína Inhibidora de la Apoptosis Ligada a X/antagonistas & inhibidores , Alanina/análogos & derivados , Alanina/síntesis química , Alanina/farmacocinética , Alanina/farmacología , Animales , Apoptosis/efectos de los fármacos , Benzodiazepinonas/síntesis química , Benzodiazepinonas/farmacocinética , Benzodiazepinonas/farmacología , Western Blotting , Caspasa 3/metabolismo , Caspasa 7/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Cristalografía por Rayos X , Femenino , Compuestos Heterocíclicos/farmacocinética , Humanos , Proteínas Inhibidoras de la Apoptosis/química , Proteínas Inhibidoras de la Apoptosis/metabolismo , Ratones , Ratones Desnudos , Modelos Químicos , Modelos Moleculares , Estructura Molecular , Estructura Terciaria de Proteína , Ubiquitina-Proteína Ligasas , Proteína Inhibidora de la Apoptosis Ligada a X/química , Proteína Inhibidora de la Apoptosis Ligada a X/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
A novel series of oxindole-type inhibitors of CDK2 that have heteroatom substituted alkynyl moieties at their C-4 position is described. These novel 4-alkynyl-substituted inhibitors have superior potency relative to their parent compound in free enzyme and in cell based assays. The crystal structure of CDK2 in complex with one of these analogues was determined and gives insight to their increased potency. The biochemical evaluation of a representative derivative is also described.
Asunto(s)
Quinasas CDC2-CDC28/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Indoles/farmacología , División Celular/efectos de los fármacos , Línea Celular Tumoral , Quinasa 2 Dependiente de la Ciclina , ADN/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/química , Humanos , Indoles/química , Modelos Moleculares , Conformación Molecular , Paclitaxel/farmacología , Relación Estructura-ActividadRESUMEN
A novel class of 3,5,6-trisubstituted naphthostyril analogues was designed and synthesized to study the structure-activity relationship for inhibition of cyclin-dependent kinase 2 (CDK2). These compounds, particularly molecules with side-chain modifications providing additional hydrogen bonding capability, were demonstrated to be potent CDK2 inhibitors with cellular activities consistent with CDK2 inhibition. These molecules inhibited tumor cell proliferation and G1-S and G2-M cell-cycle progression in vitro. The X-ray crystal structure of a 2-aminoethyleneamine derivative bound to CDK2, refined to 2.5A resolution, is presented.