Long-term exposure to retinoic acid induces the expression of IRK1 channels in HERG channel-endowed neuroblastoma cells.
Biochem Biophys Res Commun
; 244(3): 706-11, 1998 Mar 27.
Article
em En
| MEDLINE
| ID: mdl-9535729
ABSTRACT
The modulation of inward K+ conductances was studied during neuronal differentiation of human SH-SY5Y neuroblastoma cells. Under standard culture conditions, these cells express the herg gene, and the HERG current is the main inward K+ current regulating their Vrest. After 10-20 days exposure to Retinoic Acid (RA), SH-SY5Y cells showed, in addition to HERG currents, a novel current characterized by inward rectification, dependence on the extracellular K+ concentration, and blockade by Cs+ and Ba2+, the main features of the IRK1 current. The appearance of this current is accompanied by a strong hyperpolarisation of Vrest. RT-PCR experiments confirmed that a transcript of the IRK1 (Kir 2.1) gene actually appears in SH-SY5Y cells treated for 10-20 days with RA. On the whole, data here presented demonstrate that RA-induced neuronal differentiation of neuroblastoma cells is accompanied by the switch from a HERG-driven to a IRK1-driven control of Vrest, similarly to what happens in normal differentiating neurons; however, in tumor cells, this switch does not imply the abolition of HERG channel expression.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tretinoína
/
Canais de Potássio
/
Transativadores
/
Canais de Potássio Corretores do Fluxo de Internalização
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Canais de Potássio de Abertura Dependente da Tensão da Membrana
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Proteínas de Transporte de Cátions
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Proteínas de Ligação a DNA
/
Neurônios
Limite:
Humans
Idioma:
En
Revista:
Biochem Biophys Res Commun
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
Itália