Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
3.
Oncotarget ; 6(29): 28211-22, 2015 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-26375439

RESUMEN

Recently, MET exon 14 deletion (METex14del) has been postulated to be one potential mechanism for MET protein overexpression. We screened for the presence of METex14del transcript by multiplexed fusion transcript analysis using nCounter assay followed by confirmation with quantitative reverse transcription PCR with correlation to MET protein expression by immunohistochemistry (IHC) and MET amplification by fluorescence in situ hybridization (FISH). We extracted RNAs from 230 patients enrolled onto the prospective molecular profiling clinical trial (NEXT-1) (NCT02141152) between November 2013 and August 2014. Thirteen METex14del cases were identified including 3 gastric cancer, 4 colon cancer, 5 non-small cell lung cancer, and one adenocarcinoma of unknown primary. Of these 13 METex14del cases, 11 were MET IHC 3+ and 2 were 2+. Only one out of the 13 METex14del cases was MET amplified (MET/CEP ratio > 2.0). Growths of two (gastric, colon) METex14del+ patient tumor derived cell lines were profoundly inhibited by both MET tyrosine kinase inhibitors and a monoclonal antibody targeting MET. In conclusion, METex14del is a unique molecular aberration present in gastrointestinal (GI) malignancies corresponding with overexpression of MET protein but rarely with MET amplification. Substantial growth inhibition of METex14del+ patient tumor derived cell lines by several MET targeting drugs strongly suggests METex14del is a potential actionable driver mutation in GI malignancies.


Asunto(s)
Exones/genética , Neoplasias Gastrointestinales/genética , Proteínas Proto-Oncogénicas c-met/genética , Eliminación de Secuencia , Adulto , Anciano , Anciano de 80 o más Años , Secuencia de Aminoácidos , Anilidas/farmacología , Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales Humanizados , Proliferación Celular/efectos de los fármacos , Proliferación Celular/genética , Análisis Mutacional de ADN/métodos , Femenino , Neoplasias Gastrointestinales/metabolismo , Neoplasias Gastrointestinales/patología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Immunoblotting , Inmunohistoquímica , Hibridación Fluorescente in Situ , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Estudios Prospectivos , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-met/inmunología , Proteínas Proto-Oncogénicas c-met/metabolismo , Piridinas/farmacología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Tumorales Cultivadas
4.
Sci Rep ; 4: 4980, 2014 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-24828152

RESUMEN

The Met receptor tyrosine kinase is an attractive target for cancer therapy as it promotes invasive tumor growth. SAIT301 is a novel anti-Met antibody, which induces LRIG1-mediated Met degradation and inhibits tumor growth. However, detailed downstream mechanism by which LRIG1 mediates target protein down-regulation is unknown. In the present study, we discovered that SAIT301 induces ubiquitination of LRIG1, which in turn promotes recruitment of Met and LRIG1 complex to the lysosome through its interaction with Hrs, resulting in concomitant degradation of both LRIG1 and Met. We also identified USP8 as a LRIG1-specific deubiquitinating enzyme, reporting the interaction between USP8 and LRIG1 for the first time. SAIT301 triggers degradation of LRIG1 by inhibiting the interaction of LRIG1 and USP8, which regulates ubiquitin modification and stability of LRIG1. In summary, SAIT301 employs ubiquitination of LRIG1 for its highly effective Met degradation. This unique feature of SAIT301 enables it to function as a fully antagonistic antibody without Met activation. We found that USP8 is involved in deubiquitination of LRIG1, influencing the efficiency of Met degradation. The relation of Met, LRIG1 and USP8 strongly supports the potential clinical benefit of a combination treatment of a USP8 inhibitor and a Met inhibitor, such as SAIT301.


Asunto(s)
Endopeptidasas/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas Proto-Oncogénicas c-met/metabolismo , Ubiquitina Tiolesterasa/metabolismo , Ubiquitinación/fisiología , Línea Celular Tumoral , Humanos , Lisosomas/metabolismo , Proteolisis
5.
Mol Cells ; 34(6): 523-9, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23180291

RESUMEN

c-Met, the high affinity receptor for hepatocyte growth factor (HGF), is one of the most frequently activated tyrosine kinases in many human cancers and a target for cancer therapy. However, inhibitory targeting of c-Met with antibodies has proven difficult, because most antibodies have intrinsic agonist activity. Therefore, the strategy for reducing the agonism is critical for successful development of cancer therapies based on anti-c-Met antibodies. Here we developed a mechanism-based assay method for rapid screening of anti-c-Met antibodies, involving the determination of Akt phosphorylation and c-Met degradation for agonism and efficacy, respectively. Using the method, we identified an antibody, F46, that binds to human c-Met with high affinity (Kd = 2.56 nM) and specificity, and induces the degradation of c-Met in multiple cancer cells (including MKN45, a gastric cancer cell line) with minimal activation of c-Met signaling. F46 induced c-Met internalization in both HGF-dependent and HGF-independent cells, suggesting that the degradation of c-Met results from antibody-mediated receptor internalization. Furthermore, F46 competed with HGF for binding to c-Met, resulting in the inhibition of both HGF-mediated invasion and angiogenesis. Consistently, F46 inhibited the proliferation of MKN45 cells, in which c-Met is constitutively activated in an HGF-independent manner. Xenograft analysis revealed that F46 markedly inhibits the growth of subcutaneously implanted gastric and lung tumors. These results indicate that F46, identified by a novel mechanism-based assay, induces c-Met degradation with minimal agonism, implicating a potential role of F46 in therapy of human cancers.


Asunto(s)
Isoanticuerpos/química , Neoplasias/tratamiento farmacológico , Proteínas Proto-Oncogénicas c-met/metabolismo , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/metabolismo , Línea Celular Tumoral , Proliferación Celular , Factor de Crecimiento de Hepatocito/antagonistas & inhibidores , Factor de Crecimiento de Hepatocito/metabolismo , Humanos , Isoanticuerpos/metabolismo , Neoplasias/metabolismo , Neovascularización Patológica , Ensayos Antitumor por Modelo de Xenoinjerto
6.
Biochem Biophys Res Commun ; 415(4): 720-6, 2011 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-22085717

RESUMEN

Breast cancer metastasis suppressor 1 (BRMS1) suppresses metastasis without affecting primary tumorigenesis. The regulatory mechanism of BRMS1 at the protein level has not been revealed until recently. Here, we found that cullin 3 (Cul3), a component of E3 ubiquitin ligase, is a new binding partner of BRMS1 and the interaction between BRMS1 and Cul3 is mediated by the SPOP adaptor protein. Intriguingly, BRMS1 turns out to be a potent substrate that is ubiquitinated by the Cul3-SPOP complex. Knockdown of SPOP increases the level of BRMS1 protein and represses the expression of BRMS1 repressive target genes such as OPN and uPA in breast cancer cells. These results suggest that the novel regulatory mechanism of BRMS1 by Cul3-SPOP complex is important for breast cancer progression.


Asunto(s)
Proteínas Cullin/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Represoras/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Línea Celular Tumoral , Proteínas Cullin/genética , Femenino , Células HEK293 , Humanos , Estabilidad Proteica , Ubiquitinación
7.
Mol Cell ; 39(1): 71-85, 2010 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-20603076

RESUMEN

Lysine methylation within histones is crucial for transcriptional regulation and thus links chromatin states to biological outcomes. Although recent studies have extended lysine methylation to nonhistone proteins, underlying molecular mechanisms such as the upstream signaling cascade that induces lysine methylation and downstream target genes modulated by this modification have not been elucidated. Here, we show that Reptin, a chromatin-remodeling factor, is methylated at lysine 67 in hypoxic conditions by the methyltransferase G9a. Methylated Reptin binds to the promoters of a subset of hypoxia-responsive genes and negatively regulates transcription of these genes to modulate cellular responses to hypoxia.


Asunto(s)
Proteínas Portadoras/metabolismo , ADN Helicasas/metabolismo , ATPasas Asociadas con Actividades Celulares Diversas , Animales , Hipoxia de la Célula/genética , Línea Celular , Femenino , Regulación Neoplásica de la Expresión Génica , Antígenos de Histocompatibilidad/metabolismo , N-Metiltransferasa de Histona-Lisina/metabolismo , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Lisina/metabolismo , Metilación , Ratones , Modelos Biológicos , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patología , Análisis de Secuencia por Matrices de Oligonucleótidos , Regiones Promotoras Genéticas/genética , Unión Proteica , Ensayos Antitumor por Modelo de Xenoinjerto
8.
Biochem Biophys Res Commun ; 393(1): 179-84, 2010 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-20123085

RESUMEN

KAI1 is a metastasis suppressor gene known to inhibit cancer metastasis without affecting primary tumorigenicity. Although KAI1 expression has been reported to undergo transcriptional regulation, how its expression is up- or down-regulated by specific upstream signaling pathways has not been studied in detail. In this study, we characterized the regulatory elements within the 500bp upstream region of mouse KAI1 gene and identified a functional hypoxia-response element (HRE) within the promoter region. Hypoxia-dependent induction of KAI1 was directly mediated by hypoxia-inducible factor (HIF)-1alpha binding on the promoter, which subsequently caused increased recruitment of RNA polymerase II for transcriptional activation. The failure of HIF-1alpha recruitment to the KAI1 promoter was observed in Hif-1alpha knockout mouse embryonic fibroblasts. Furthermore, KAI1 protein synthesis was markedly increased in ischemic tissues, suggesting that KAI1 is a hypoxia target gene in vivo.


Asunto(s)
Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Hipoxia/genética , Proteína Kangai-1/genética , Oxígeno/metabolismo , Activación Transcripcional , Animales , Hipoxia de la Célula/genética , Línea Celular , Humanos , Hipoxia/metabolismo , Ratones , Isquemia Miocárdica/genética , Isquemia Miocárdica/metabolismo , Células 3T3 NIH , Regiones Promotoras Genéticas , Elementos de Respuesta
9.
Nat Cell Biol ; 8(6): 631-9, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16699503

RESUMEN

Defining the functional modules within transcriptional regulatory factors that govern switching between repression and activation events is a central issue in biology. Recently, we have reported the dynamic role of a beta-catenin-reptin chromatin remodelling complex in regulating a metastasis suppressor gene KAI1 (ref.1), which is capable of inhibiting the progression of tumour metastasis. Here, we identify signalling factors that confer repressive function on reptin and hence repress the expression of KAI1. Biochemical purification of a reptin-containing complex has revealed the presence of specific desumoylating enzymes that reverse the sumoylation of reptin that underlies its function as a repressor. Desumoylation of reptin alters the repressive function of reptin and its association with HDAC1. Furthermore, the sumoylation status of reptin modulates the invasive activity of cancer cells with metastatic potential. These data clearly define a functional model and provide a novel link for SUMO modification in cancer metastasis.


Asunto(s)
Proteínas Portadoras/fisiología , Cromatina/metabolismo , ADN Helicasas/fisiología , Metástasis de la Neoplasia , Proteínas Modificadoras Pequeñas Relacionadas con Ubiquitina/metabolismo , ATPasas Asociadas con Actividades Celulares Diversas , Proteínas Portadoras/metabolismo , Línea Celular Tumoral , ADN Helicasas/metabolismo , Regulación de la Expresión Génica , Histona Desacetilasa 1 , Histona Desacetilasas/metabolismo , Humanos , Proteína Kangai-1/genética , Unión Proteica , Proteínas Represoras , Transducción de Señal
10.
Nature ; 434(7035): 921-6, 2005 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-15829968

RESUMEN

Defining the molecular strategies that integrate diverse signalling pathways in the expression of specific gene programmes that are critical in homeostasis and disease remains a central issue in biology. This is particularly pertinent in cancer biology because downregulation of tumour metastasis suppressor genes is a common occurrence, and the underlying molecular mechanisms are not well established. Here we report that the downregulation of a metastasis suppressor gene, KAI1, in prostate cancer cells involves the inhibitory actions of beta-catenin, along with a reptin chromatin remodelling complex. This inhibitory function of beta-catenin-reptin requires both increased beta-catenin expression and recruitment of histone deacetylase activity. The coordinated actions of beta-catenin-reptin components that mediate the repressive state serve to antagonize a Tip60 coactivator complex that is required for activation; the balance of these opposing complexes controls the expression of KAI1 and metastatic potential. The molecular mechanisms underlying the antagonistic regulation of beta-catenin-reptin and the Tip60 coactivator complexes for the metastasis suppressor gene, KAI1, are likely to be prototypic of a selective downregulation strategy for many genes, including a subset of NF-kappaB target genes.


Asunto(s)
Acetiltransferasas/metabolismo , Antígenos CD/genética , Proteínas del Citoesqueleto/metabolismo , Regulación Neoplásica de la Expresión Génica/genética , Glicoproteínas de Membrana/genética , Metástasis de la Neoplasia/genética , Neoplasias de la Próstata/genética , Proteínas Proto-Oncogénicas/genética , Transactivadores/metabolismo , Transcripción Genética/genética , Acetiltransferasas/genética , Animales , Línea Celular Tumoral , Ensamble y Desensamble de Cromatina , Colágeno , Regulación hacia Abajo/genética , Combinación de Medicamentos , Histona Acetiltransferasas , Humanos , Proteína Kangai-1 , Laminina , Lisina Acetiltransferasa 5 , Masculino , Ratones , FN-kappa B/metabolismo , Trasplante de Neoplasias , Regiones Promotoras Genéticas/genética , Neoplasias de la Próstata/metabolismo , Proteoglicanos , ARN Mensajero/genética , ARN Mensajero/metabolismo , beta Catenina
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...