RESUMEN
BACKGROUND: The recently described navigator proteins have a multifaceted role in cytoskeletal dynamics. We report here on the relevance of one of them, navigator 3 (NAV3), in colorectal cancer (CRC). METHODS: We analysed changes in chromosome 12 and NAV3 copy number in CRC/adenoma samples of 59 patients and in 6 CRC cell lines, using fluorescence in situ hybridisation, loss of heterozygosity, and array-CGH. NAV3 target genes were identified by siRNA depletion, expression arrays, and immunohistochemistry. RESULTS: NAV3 deletion and chromosome 12 polysomy were detected in 30 and 70% of microsatellite stability (MSS) carcinomas, in 23 and 30% of adenomas and in four of six CRC cell lines. NAV3 amplification was found in 25% of MSS samples. NAV3 alterations correlated with lymph node metastasis. In normal colon cells, NAV3 silencing induced upregulation of interleukin 23 receptor (IL23R) and gonadotropin releasing hormone receptor. In MSS and microsatellite instability tumours, IL23R immunoreactivity correlated with Dukes' staging and lymph node metastases, whereas nuclear beta-catenin correlated with lymph node metastases only. CONCLUSION: NAV3 copy number changes are frequent in CRC and in adenomas, and upregulation of IL23R, following NAV3 silencing, strongly correlates with Dukes' staging and lymph node metastases. This suggests that NAV3 has a role in linking tissue inflammation to cancer development in the colon.
Asunto(s)
Adenoma/genética , Neoplasias Colorrectales/genética , Proteínas de la Membrana/genética , Proteínas del Tejido Nervioso/genética , Adenoma/metabolismo , Adenoma/patología , Línea Celular Tumoral , Cromosomas Humanos Par 12/genética , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Regulación Neoplásica de la Expresión Génica , Humanos , Inmunohistoquímica , Hibridación Fluorescente in Situ , Repeticiones de Microsatélite , Estadificación de Neoplasias , ARN Interferente Pequeño/análisis , Receptores de Interleucina/genética , Receptores de Interleucina/metabolismo , Receptores LHRH/genética , Receptores LHRH/metabolismo , Regulación hacia Arriba/genéticaRESUMEN
We have isolated and sequenced the mouse zinc finger gene, Dnmt3l (DNA cytosine-5-methyltransferase 3-like), on mouse chromosome 10, showing similarity to members of the DNMT3/Dnmt3 family. The Dnmt3l protein contains an ADD zinc finger, which Dnmt3l shares with other Dnmt3 family members and Atrx. RT-PCR analysis showed Dnmt3l expression in testis, thymus, ovary, and heart, as well as in 7-day, 15-day, and 17-day mouse embryos.
Asunto(s)
ADN (Citosina-5-)-Metiltransferasas/genética , Secuencia de Aminoácidos , Animales , Células COS , ADN (Citosina-5-)-Metiltransferasas/análisis , ADN (Citosina-5-)-Metiltransferasas/química , Embrión de Mamíferos/enzimología , Exones/genética , Etiquetas de Secuencia Expresada , Femenino , Perfilación de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Masculino , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , Ovario/enzimología , Mapeo Físico de Cromosoma , Polimorfismo de Nucleótido Simple/genética , Estructura Terciaria de Proteína , ARN Mensajero/análisis , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Alineación de Secuencia , Análisis de Secuencia de ADN , Testículo/enzimología , Timo/enzimología , Dedos de ZincRESUMEN
We have isolated the DNMT3L gene that is related to the cytosine-5-methyltransferase 3 (DNMT3) family. The gene is located on chromosome 21q22.3 between the AIRE and the KIAA0653 genes and spans approximately 16 kb of genomic sequence. The encoded protein of 387 amino acids has a cysteine-rich region containing a novel-type zinc finger domain that is conserved in DNMT3A and DNMT3B but also in ATRX, a member of the SNF2 protein family. The novel domain, called an ADD (ATRX, DNMT3, DNMT3L)-type zinc finger, contains two subparts: a C2C2 and an imperfect PHD zinc finger. Expression of the DNMT3L mRNA was not detectable by Northern blotting; however, RT-PCR amplification revealed that it is expressed at low levels in several tissues including testis, ovary, and thymus.