RESUMEN
The activity and stability of the p53 tumor suppressor are regulated by the human homologue of the mouse double minute 2 (Hdm2) oncoprotein. It has been hypothesized that small molecules disrupting the Hdm2:p53 complex would allow for the activation of p53 and result in growth suppression. We have identified small-molecule inhibitors of the Hdm2:p53 interaction using our proprietary ThermoFluor microcalorimetry technology. Medicinal chemistry and structure-based drug design led to the development of an optimized series of benzodiazepinediones, including TDP521252 and TDP665759. Activities were dependent on the expression of wild-type (wt) p53 and Hdm2 as determined by lack of potency in mutant or null p53-expressing cell lines or cells engineered to no longer express Hdm2 and wt p53. TDP521252 and TDP665759 inhibited the proliferation of wt p53-expressing cell lines with average IC(50)s of 14 and 0.7 micromol/L, respectively. These results correlated with the direct cellular dissociation of Hdm2 from wt p53 observed within 15 minutes in JAR choriocarcinoma cells. Additional activities of these inhibitors in vitro include stabilization of p53 protein levels, up-regulation of p53 target genes in a DNA damage-independent manner, and induction of apoptosis in HepG2 cells. Administration of TDP665759 to mice led to an increase in p21(waf1/cip1) levels in liver samples. Finally, TDP665759 synergizes with doxorubicin both in culture and in an A375 xenograft model to decrease tumor growth. Taken together, these data support the potential utility of small-molecule inhibitors of the Hdm2:p53 interaction for the treatment of wt p53-expressing tumors.
Asunto(s)
Benzodiazepinonas/farmacología , Doxorrubicina/farmacología , Proteínas Proto-Oncogénicas c-mdm2/efectos de los fármacos , Proteína p53 Supresora de Tumor/efectos de los fármacos , Animales , Protocolos de Quimioterapia Combinada Antineoplásica , Apoptosis/efectos de los fármacos , Benzodiazepinas/química , Benzodiazepinas/farmacología , Benzodiazepinonas/administración & dosificación , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Doxorrubicina/administración & dosificación , Ensayos de Selección de Medicamentos Antitumorales , Sinergismo Farmacológico , Femenino , Humanos , Neoplasias Hepáticas Experimentales/tratamiento farmacológico , Neoplasias Hepáticas Experimentales/metabolismo , Ratones , Ratones Desnudos , Complejos Multiproteicos , Mutación , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The disruption of the p53-Hdm2 protein-protein interaction induces cell growth arrest and apoptosis. We have identified the 1,4-benzodiazepine-2,5-dione scaffold as a suitable template for inhibiting this interaction by binding to the Hdm2 protein. Several compounds have been made with improved potency, solubility, and cell-based activities.
Asunto(s)
Benzodiazepinas/farmacología , Proteínas Proto-Oncogénicas c-mdm2/antagonistas & inhibidores , Apoptosis/efectos de los fármacos , Benzodiazepinas/síntesis química , Benzodiazepinas/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Estructura Molecular , Unión Proteica/efectos de los fármacos , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Estereoisomerismo , Relación Estructura-Actividad , Proteína p53 Supresora de Tumor/antagonistas & inhibidores , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
The 1,4-benzodiazepine-2,5-dione is a suitable template to disrupt the interaction between p53 and Hdm2. The development of an enantioselective synthesis disclosed the stereochemistry of the active enantiomer. An in vitro p53 peptide displacement assay identified active compounds. These activities were confirmed in several cell-based assays including induction of the p53 regulated gene (PIG-3) and caspase activity.
Asunto(s)
Benzodiazepinas/química , Benzodiazepinas/farmacología , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Proteínas Proto-Oncogénicas c-mdm2/antagonistas & inhibidores , Benzodiazepinas/síntesis química , Caspasas/metabolismo , Línea Celular Tumoral , Cristalografía por Rayos X , Inhibidores Enzimáticos/química , Humanos , Enlace de Hidrógeno , Modelos Moleculares , Estructura Molecular , Mutación/genética , Proteínas Proto-Oncogénicas c-mdm2/química , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Estereoisomerismo , Relación Estructura-Actividad , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
We describe the synthesis and structure/activity relationship of RGD mimetics that are potent inhibitors of the integrin alpha(v)beta3. Indol-1-yl propionic acids containing a variety of basic moieties at the 5-position, as well as substitutions alpha and beta to the carboxy terminus were synthesized and evaluated. Novel compounds with improved potency have been identified.