RESUMEN
Background The neddylation pathway conjugates NEDD8 to cullin-RING ligases and controls the proteasomal degradation of specific proteins involved in essential cell processes. Pevonedistat (MLN4924) is a selective small molecule targeting the NEDD8-activating enzyme (NAE) and inhibits an early step in neddylation, resulting in DNA re-replication, cell cycle arrest and death. We investigated the anti-tumor potential of pevonedistat in preclinical models of melanoma. Methods Melanoma cell lines and patient-derived tumor xenografts (PDTX) treated with pevonedistat were assessed for viability/apoptosis and tumor growth, respectively, to identify sensitive/resistant models. Gene expression microarray and gene set enrichment analyses were performed in cell lines to determine the expression profiles and pathways of sensitivity/resistance. Pharmacodynamic changes in treated-PDTX were also characterized. Results Pevonedistat effectively inhibited cell viability (IC50 < 0.3 µM) and induced apoptosis in a subset of melanoma cell lines. Sensitive and resistant cell lines exhibited distinct gene expression profiles; sensitive models were enriched for genes involved in DNA repair, replication and cell cycle regulation, while immune response and cell adhesion pathways were upregulated in resistant models. Pevonedistat also reduced tumor growth in melanoma cell line xenografts and PDTX with variable responses. An accumulation of pevonedistat-NEDD8 adduct and CDT1 was observed in sensitive tumors consistent with its mechanism of action. Conclusions This study provided preclinical evidence that NAE inhibition by pevonedistat has anti-tumor activity in melanoma and supports the clinical benefits observed in recent Phase 1 trials of this drug in melanoma patients. Further investigations are warranted to develop rational combinations and determine predictive biomarkers of pevonedistat.
Asunto(s)
Antineoplásicos/farmacología , Ciclopentanos/farmacología , Melanoma/tratamiento farmacológico , Pirimidinas/farmacología , Enzimas Activadoras de Ubiquitina/antagonistas & inhibidores , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Melanoma/genética , Melanoma/metabolismo , Enzimas Activadoras de Ubiquitina/metabolismo , Ubiquitinación/efectos de los fármacosRESUMEN
The goal of this study was to investigate the activity of the selective MEK1/2 inhibitor TAK-733 in both melanoma cell lines and patient-derived melanoma xenograft models. In vitro cell proliferation assays using the sulforhodamine B assay were conducted to determine TAK-733 potency and melanoma responsiveness. In vivo murine modeling with eleven patient-derived melanoma explants evaluated daily dosing of TAK-733 at 25 or 10 mg/kg. Immunoblotting was performed to evaluate on-target activity and downstream inhibition by TAK-733 in both in vitro and in vivo studies. TAK-733 demonstrated broad activity in most melanoma cell lines with relative resistance observed at IC50 > 0.1 µmol/L in vitro. TAK-733 also exhibited activity in 10 out of 11 patient-derived explants with tumor growth inhibition ranging from 0% to 100% (P < 0.001-0.03). Interestingly, BRAF(V600E) and NRAS mutational status did not correlate with responsiveness to TAK-733. Pharmacodynamically, pERK was suppressed in sensitive cell lines and tumor explants, confirming TAK-733-mediated inhibition of MEK1/2, although the demonstration of similar effects in the relatively resistant cell lines and tumor explants suggests that escape pathways are contributing to melanoma survival and proliferation. These data demonstrate that TAK-733 exhibits robust tumor growth inhibition and regression against human melanoma cell lines and patient-derived xenograft models, suggesting that further clinical development in melanoma is of scientific interest. Particularly interesting is the activity in BRAF wild-type models, where current approved therapy such as vemurafenib has been reported not to be active.
Asunto(s)
Antineoplásicos/farmacología , Melanoma/patología , Inhibidores de Proteínas Quinasas/farmacología , Piridonas/farmacología , Pirimidinonas/farmacología , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Resistencia a Antineoplásicos/efectos de los fármacos , Femenino , Humanos , Immunoblotting , Cinética , Ratones Desnudos , Inhibidores de Proteínas Quinasas/farmacocinética , Piridonas/farmacocinética , Pirimidinonas/farmacocinética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
PURPOSE: The mitogen-activated protein kinase (MAPK) pathway is a crucial regulator of cell proliferation, survival, and resistance to apoptosis. MEK inhibitors are being explored as a treatment option for patients with KRAS-mutant colorectal cancer who are not candidates for EGFR-directed therapies. Initial clinical results of MEK inhibitors have yielded limited single-agent activity in colorectal cancer, indicating that rational combination strategies are needed. EXPERIMENTAL DESIGN: In this study, we conducted unbiased gene set enrichment analysis and synthetic lethality screens with selumetinib, which identified the noncanonical Wnt/Ca++ signaling pathway as a potential mediator of resistance to the MEK1/2 inhibitor selumetinib. To test this, we used shRNA constructs against relevant WNT receptors and ligands resulting in increased responsiveness to selumetinib in colorectal cancer cell lines. Further, we evaluated the rational combination of selumetinib and WNT pathway modulators and showed synergistic antiproliferative effects in in vitro and in vivo models of colorectal cancer. RESULTS: Importantly, this combination not only showed tumor growth inhibition but also tumor regression in the more clinically relevant patient-derived tumor explant (PDTX) models of colorectal cancer. In mechanistic studies, we observed a trend toward increased markers of apoptosis in response to the combination of MEK and WntCa(++) inhibitors, which may explain the observed synergistic antitumor effects. CONCLUSIONS: These results strengthen the hypothesis that targeting both the MEK and Wnt pathways may be a clinically effective rational combination strategy for patients with metastatic colorectal cancer.
Asunto(s)
Bencimidazoles/administración & dosificación , Neoplasias Colorrectales/tratamiento farmacológico , Ciclosporina/administración & dosificación , Inhibidores de Proteínas Quinasas/administración & dosificación , Apoptosis , Calcio/metabolismo , Señalización del Calcio/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Humanos , Quinasas Quinasa Quinasa PAM/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas p21(ras) , Transducción de Señal/efectos de los fármacos , Vía de Señalización Wnt/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto , Proteínas ras/genéticaRESUMEN
The ubiquitin proteasome system (UPS) regulates the ubiquitination, and thus degradation and turnover, of many proteins vital to cellular regulation and function. The UPS comprises a sequential series of enzymatic processes using four key enzyme families: E1 (ubiquitin-activating enzymes), E2 (ubiquitin-carrier proteins), E3 (ubiquitin-protein ligases), and E4 (ubiquitin chain assembly factors). Because the UPS is a crucial regulator of the cell cycle, and abnormal cell-cycle control can lead to oncogenesis, aberrancies within the UPS pathway can result in a malignant cellular phenotype and thus has become an attractive target for novel anticancer agents. This article will provide an overall review of the mechanics of the UPS, describe aberrancies leading to cancer, and give an overview of current drug therapies selectively targeting the UPS.
Asunto(s)
Antineoplásicos/farmacología , Transformación Celular Neoplásica , Complejo de la Endopetidasa Proteasomal/fisiología , Enzimas Activadoras de Ubiquitina/fisiología , Enzimas Ubiquitina-Conjugadoras/fisiología , Ubiquitina-Proteína Ligasas/fisiología , Antineoplásicos/uso terapéutico , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/fisiología , Proteínas de Unión al ADN/fisiología , Humanos , Masculino , Mutación , Proteínas Oncogénicas Virales/fisiología , Neoplasias de la Próstata/genética , Complejo de la Endopetidasa Proteasomal/efectos de los fármacos , Proteínas Proto-Oncogénicas c-mdm2/fisiología , Proteína p53 Supresora de Tumor/fisiología , Ubiquitina-Proteína Ligasas/antagonistas & inhibidores , Ubiquitina-Proteína Ligasas/genéticaRESUMEN
Ethanol locks have been used to treat catheter infections and to decrease the rate at which they occur. Catheter-related infections caused by Candida spp. are especially difficult to manage medically and usually require catheter removal. We report 3 consecutive patients whose catheter infections caused by Candida were successfully treated with a combination of ethanol lock therapy and systemic antifungals.