Evaluation of the NK2 homeobox 1 gene (NKX2-1) as a Hirschsprung's disease locus.

Garcia-Barceló, M-M; Lau, D K; Ngan, E S; Leon, T Y; Liu, T; So, M; Miao, X; Lui, V C; Wong, K K; Ganster, R W; Cass, D T; Croaker, G D H; Tam, P K

Garcia-Barceló, M-M; Lau, D K; Ngan, E S; Leon, T Y; Liu, T; So, M; Miao, X; Lui, V C; Wong, K K; Ganster, R W; Cass, D T; Croaker, G D H; Tam, P K.

Afiliación

Garcia-Barceló MM; Division of Paediatric Surgery, Department of Surgery, Li Ka Shing Faculty of Medicine of the University of Hong Kong, Hong Kong SAR, China. mmgarcia@hkucc.hku.hk

Ann Hum Genet ; 72(Pt 2): 170-7, 2008 Mar.

Article en En | MEDLINE | ID: mdl-18081917

RESUMEN

Hirschsprung's disease (HSCR, colonic aganglionosis) is an oligogenic entity that usually requires mutations in RET and other interacting loci. Decreased levels of RET expression may lead to the manifestation of HSCR. We previously showed that RET transcription was decreased due to alteration of the NKX2-1 binding site by two HSCR-associated RET promoter single nucleotide polymorphisms (SNPs). This prompted us to investigate whether DNA alterations in NKX2-1 could play a role in HSCR by affecting the RET-regulatory properties of the NKX2-1 protein. Our initial study on 86 Chinese HSCR patients revealed a Gly322Ser amino acid substitution in the NKX2-1 protein. In this study, we have examined 102 additional Chinese and 70 Caucasian patients and 194 Chinese and 60 Caucasian unselected, unrelated, subjects as controls. The relevance of the DNA changes detected in NKX2-1 by direct sequencing were evaluated using bioinformatics, reporter and binding-assays, mouse neurosphere culture, immunohistochemistry and immunofluorescence techniques. Met3Leu and Pro48Pro were identified in 2 Caucasian and 1 Chinese patients respectively. In vitro analysis showed that Met3Leu reduced the activity of the RET promoter by 100% in the presence of the wild-type or HSCR-associated RET promoter SNP alleles. The apparent binding affinity of the NKX2-1 mutated protein was not decreased. The Met3Leu mutation may affect the interaction of NKX2-1 with its protein partners. The absence of NKX2-1 expression in mouse but not in human gut suggests that the role of NKX2-1 in gut development differs between the two species. NKX2-1 mutations could contribute to HSCR by affecting RET expression through defective interactions with other transcription factors.

Asunto(s)

Predisposición Genética a la Enfermedad/genética; Enfermedad de Hirschsprung/genética; Proteínas Nucleares/genética; Proteínas Proto-Oncogénicas c-ret/metabolismo; Factores de Transcripción/genética; Animales; Pueblo Asiatico/genética; Australia; Secuencia de Bases; Línea Celular Tumoral; China; Biología Computacional; Sistema Digestivo/embriología; Sistema Digestivo/metabolismo; Ensayo de Cambio de Movilidad Electroforética; Técnica del Anticuerpo Fluorescente; Componentes del Gen; Genotipo; Humanos; Inmunohistoquímica; Ratones; Datos de Secuencia Molecular; Mutación/genética; Proteínas Nucleares/metabolismo; Proteínas Proto-Oncogénicas c-ret/genética; Reacción en Cadena de la Polimerasa de Transcriptasa Inversa; Análisis de Secuencia de ADN; Factor Nuclear Tiroideo 1; Factores de Transcripción/metabolismo; Población Blanca/genética

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Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Factores de Transcripción / Proteínas Nucleares / Predisposición Genética a la Enfermedad / Proteínas Proto-Oncogénicas c-ret / Enfermedad de Hirschsprung Tipo de estudio: Prognostic_studies Límite: Animals / Humans País/Región como asunto: Asia / Oceania Idioma: En Revista: Ann Hum Genet Año: 2008 Tipo del documento: Article País de afiliación: China Pais de publicación: Reino Unido

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