RESUMEN
Aberrant activation of signaling through the RAS-RAF-MEK-ERK (MAPK) pathway is implicated in numerous cancers, making it an attractive therapeutic target. Although BRAF and MEK-targeted combination therapy has demonstrated significant benefit beyond single-agent options, the majority of patients develop resistance and disease progression after approximately 12 months. Reactivation of ERK signaling is a common driver of resistance in this setting. Here we report the discovery of BVD-523 (ulixertinib), a novel, reversible, ATP-competitive ERK1/2 inhibitor with high potency and ERK1/2 selectivity. In vitro BVD-523 treatment resulted in reduced proliferation and enhanced caspase activity in sensitive cells. Interestingly, BVD-523 inhibited phosphorylation of target substrates despite increased phosphorylation of ERK1/2. In in vivo xenograft studies, BVD-523 showed dose-dependent growth inhibition and tumor regression. BVD-523 yielded synergistic antiproliferative effects in a BRAFV600E-mutant melanoma cell line xenograft model when used in combination with BRAF inhibition. Antitumor activity was also demonstrated in in vitro and in vivo models of acquired resistance to single-agent and combination BRAF/MEK-targeted therapy. On the basis of these promising results, these studies demonstrate BVD-523 holds promise as a treatment for ERK-dependent cancers, including those whose tumors have acquired resistance to other treatments targeting upstream nodes of the MAPK pathway. Assessment of BVD-523 in clinical trials is underway (NCT01781429, NCT02296242, and NCT02608229). Mol Cancer Ther; 16(11); 2351-63. ©2017 AACR.
Asunto(s)
Aminopiridinas/administración & dosificación , Melanoma/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/administración & dosificación , Proteínas Proto-Oncogénicas B-raf/genética , Pirroles/administración & dosificación , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Resistencia a Antineoplásicos/genética , Humanos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Melanoma/genética , Melanoma/patología , Ratones , Mutación , Proteínas Proto-Oncogénicas B-raf/antagonistas & inhibidores , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Noscapine and its 7-hydroxy and 7-amino derivatives were characterized for their binding to tubulin. A solution NMR structure of these compounds bound to tubulin shows that noscapine and its 7-aniline derivative do not compete for the same binding site nor does its small molecule crystal structure match its tubulin-bound conformation. These compounds were also tested for their antiproliferative effects on a panel hepatocellular carcinoma cell lines.
Asunto(s)
Compuestos de Anilina/síntesis química , Antineoplásicos/síntesis química , Noscapina/análogos & derivados , Noscapina/síntesis química , Moduladores de Tubulina/síntesis química , Tubulina (Proteína)/química , Compuestos de Anilina/farmacología , Antineoplásicos/farmacología , Sitios de Unión , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Cristalografía por Rayos X , Ensayos de Selección de Medicamentos Antitumorales , Fluorescencia , Humanos , Espectroscopía de Resonancia Magnética , Conformación Molecular , Noscapina/farmacología , Unión Proteica , Soluciones , Relación Estructura-Actividad , Moduladores de Tubulina/farmacologíaRESUMEN
The signal transducer Stat5 plays a key role in the regulation of hematopoietic differentiation and hematopoietic stem cell function. To evaluate the effects of Stat5 signaling in the earliest hematopoietic progenitors, we have generated an embryonic stem cell line in which Stat5 signaling can be induced with doxycycline. Ectopic Stat5 activation at the point of origin of the hematopoietic lineage (from day 4 to day 6 of embryoid body differentiation) significantly enhances the number of hematopoietic progenitors with colony-forming potential. It does so without significantly altering total numbers or apoptosis of hematopoietic cells, suggesting a cell-intrinsic effect of Stat5 on either the developmental potential or clonogenicity of this population. From day-6 embryoid bodies, under the influence of Stat5 signaling, a population of semiadherent cells can be expanded on OP9 stromal cells that is comprised of primitive hematopoietic blast cells with ongoing, mainly myeloid, differentiation. When these cells are injected into lethally irradiated mice, they engraft transiently in a doxycycline-dependent manner. These results demonstrate that the hematopoietic commitment of embryonic stem cells may be augmented by a Stat5-mediated signal, and highlight the utility of manipulating individual components of signaling pathways for engineering tissue-specific differentiation of stem cells.
Asunto(s)
Proteínas de Unión al ADN/genética , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/metabolismo , Proteínas de la Leche , Transactivadores/genética , Animales , Técnicas de Cultivo de Célula , Diferenciación Celular , Línea Celular , Proteínas de Unión al ADN/metabolismo , Doxiciclina/farmacología , Expresión Génica/efectos de los fármacos , Proteínas Fluorescentes Verdes , Hematopoyesis/genética , Trasplante de Células Madre Hematopoyéticas , Células Madre Hematopoyéticas/efectos de los fármacos , Proteínas Luminiscentes/genética , Ratones , Proteínas Recombinantes/genética , Factor de Transcripción STAT5 , Transducción de Señal/efectos de los fármacos , Células del Estroma/citología , Células del Estroma/metabolismo , Transactivadores/metabolismoRESUMEN
The development of chronic myeloid leukemia (CML) is dependent on the deregulated tyrosine kinase of the oncoprotein BCR-ABL. STI571 (imatinib mesylate), an abl tyrosine kinase inhibitor, has proven remarkably effective for the treatment of CML. However, resistance to STI571 because of enhanced expression or mutation of the BCR-ABL gene has been detected in patients. In the current study we show that the farnesyl transferase inhibitor (FTI) SCH66336 (lonafarnib) inhibits the proliferation of STI571-resistant BCR-ABL-positive cell lines and hematopoietic colony formation from peripheral blood samples of STI571-resistant patients with CML. Moreover, SCH66336 enhances STI571-induced apoptosis in STI571-sensitive cells and, in patients with STI571 resistance from gene amplification, cooperates with STI571 to induce apoptosis. Our data provide a rationale for combination clinical trials of STI571 and SCH66336 in CML patients and suggest that combination therapy may be effective in patients with STI571 resistance.