RESUMEN
The anaplastic lymphoma kinase (ALK), tyrosine kinase oncogene is implicated in a wide variety of cancers. In this study we used conditional onco-ALK (NPM-ALK and TPM3-ALK) mouse MEF cell lines (ALK+ fibroblasts) and transgenic models (ALK+ B-lymphoma) to investigate the involvement and regulation of angiogenesis in ALK tumor development. First, we observed that ALK expression leads to downregulation of miR-16 and increased Vascular Endothelial Growth Factor (VEGF) levels. Second, we found that modification of miR-16 levels in TPM3-ALK MEF cells greatly affected VEGF levels. Third, we demonstrated that miR-16 directly interacts with VEGF mRNA at the 3'-untranslated region and that the regulation of VEGF by miR-16 occurs at the translational level. Fourth, we showed that expression of both the ALK oncogene and hypoxia-induced factor 1α (HIF1α) is a prerequisite for miR-16 downregulation. Fifth, in vivo, miR-16 gain resulted in reduced angiogenesis and tumor growth. Finally, we highlighted an inverse correlation between the levels of miR-16 and VEGF in human NPM-ALK+ Anaplastic Large Cell Lymphomas (ALCL). Altogether, our results demonstrate, for the first time, the involvement of angiogenesis in ALK+ ALCL and strongly suggest an important role for hypoxia-miR-16 in regulating VEGF translation.
Asunto(s)
Regulación Neoplásica de la Expresión Génica , Hipoxia/metabolismo , Linfoma Anaplásico de Células Grandes/genética , Linfoma Anaplásico de Células Grandes/metabolismo , MicroARNs/genética , Proteínas Tirosina Quinasas Receptoras/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Quinasa de Linfoma Anaplásico , Animales , Northern Blotting , Western Blotting , Estudios de Casos y Controles , Adhesión Celular , Movimiento Celular , Células Cultivadas , Metilación de ADN , Regulación hacia Abajo , Embrión de Mamíferos/citología , Embrión de Mamíferos/metabolismo , Ensayo de Inmunoadsorción Enzimática , Femenino , Fibroblastos/citología , Fibroblastos/metabolismo , Humanos , Hipoxia/genética , Hipoxia/patología , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Técnicas para Inmunoenzimas , Linfoma Anaplásico de Células Grandes/patología , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , MicroARNs/metabolismo , Neovascularización Patológica , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Proteínas Tirosina Quinasas Receptoras/genética , Factor A de Crecimiento Endotelial Vascular/genéticaRESUMEN
We investigated gene expression patterns that occur during taro corm development. Two-dimensional gel electrophoresis identified several different prevalent proteins that accumulate during corm development. Microsequencing studies indicated that some of these proteins are related to taste-modifying proteins, such as curculin and miraculin, and proteins found in other storage organs, such as sporamin and the Kunitz trypsin inhibitor. A curculin-encoding cDNA clone, designated as TC1, was identified that corresponds to a highly prevalent 1-kb corm mRNA. The TC1 mRNA accumulates during corm development, is more prevalent in corm apical than basal regions, and is either absent, or present at low concentrations, in other vegetative organs such as the leaf and root. In situ hybridization experiments showed that the TC1 mRNA is highly concentrated in corm storage parenchyma cells and is absent, or present in reduced concentrations, in other corm cells and tissues. Our results show that corm development is associated with the differentiation of specialized cells and tissues, and that these differentiation events are coupled with the temporal and spatial expression of corm-specific genes.
Asunto(s)
Expresión Génica , Plantas Comestibles/genética , Secuencia de Aminoácidos , Diferenciación Celular , Biblioteca de Genes , Globulinas/genética , Globulinas/metabolismo , Datos de Secuencia Molecular , Proteínas de Vegetales Comestibles/genética , Proteínas de Vegetales Comestibles/metabolismo , Plantas Comestibles/citología , Plantas Comestibles/crecimiento & desarrollo , ARN Mensajero/genética , Homología de Secuencia , Homología de Secuencia de AminoácidoRESUMEN
Two genes, BE2S1 and BE2S2, coding for methionine-rich albumins of Brazil nut (Bertholletia excelsa H.B.K.) have been cloned and their sequence determined. The genes are members of a multigene family and one of them, i.e. BE2S1, codes for one of the dominant 2S isoforms. Its expression is highly regulated during seed development and with respect to tissue specificity. Sequence analysis has shown that the genes contain one intron and that the promoter of BE2S1 shows a canonical TATA motif. The transcription initiation site is located 26 nucleotides downstream from the TATA box. Sequence comparison of the promoter regions of 2S genes from Brassica napus, Arabidopsis thaliana and B. excelsa revealed the presence of TGCA palindromic sequence that appear to be arranged in a 2S-specific manner.