In vivo and in vitro analysis of the human tissue-type plasminogen activator gene promoter in neuroblastomal cell lines: evidence for a functional upstream kappaB element.
J Thromb Haemost
; 3(5): 1009-17, 2005 May.
Article
em En
| MEDLINE
| ID: mdl-15869598
ABSTRACT
Besides its well-established role in wound healing and fibrinolysis, tissue-type plasminogen activator (t-PA) has been shown to contribute to cognitive processes and memory formation within the central nervous system, and to promote glutamate receptor-mediated excitotoxicity. The t-PA gene is expressed and regulated in neuronal cells but the regulatory transcriptional processes directing this expression are still poorly characterized. We have used DNase I-hypersensitivity mapping and in vivo foot printing to identify putative regulatory elements and transcription factor binding sites in two human neuroblastomal (KELLY and SK-N-SH) and one human glioblastomal (SNB-19) cell lines. Hypersensitive sites were found in the proximal promoter region of all cell lines, and within the first exon for KELLY and SNB-19 cells. Mapping of methylation-protected residues in vivo detected a cluster of protected residues corresponding to a cAMP response element (CRE) and Sp1 sites in the proximal promoter previously shown to be essential for basal expression in other cell types. Protected residues were also found at other sites, notably a kappaB element at position bp -3081 to -3072 that was partly protected in KELLY and SNB-19 cells. Analysis of transfected reporter constructs in KELLY and SNB-19 cells confirmed that this particular element is functionally significant in the transactivation of the t-PA promoter in both cell types. This study defines, by in vivo and in vitro methods, a previously undescribed kappaB site in the t-PA gene promoter that influences t-PA expression in neuronal cells.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Regiões Promotoras Genéticas
/
Ativador de Plasminogênio Tecidual
/
Neuroblastoma
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2005
Tipo de documento:
Article