Unbalanced activation of ERK1/2 and MEK1/2 in apigenin-induced HeLa cell death.
Exp Cell Res
; 299(1): 15-26, 2004 Sep 10.
Article
em En
| MEDLINE
| ID: mdl-15302569
ABSTRACT
Apigenin, a dietary bioflavonoid with anticarcinogenic properties, was highly cytotoxic for HeLa cells (incubated with 0.5% FBS). This effect was accompanied with a marked increase in ERK1/2 but not MEK1/2 phosphorylation. The cytotoxic effects of apigenin were attenuated by the stimulation of these cells with 10% FBS, which provoked an increase in the phosphorylation levels of MEK1/2 and ERK1/2. The steps in the ERK1/2 pathway relevant to the cytotoxic effects of apigenin, as well as the contribution of other signaling pathways, were investigated. The activation of the pathway by transfection with the constitutively active Ras mutant (RasV12) conferred protection to serum-starved HeLa cells against apigenin, whereas the constitutively active MEK(E) mutant did not. MEK inhibitors (PD098059 or U0126) blocked ERK1/2 phosphorylation induced by apigenin and conferred partial protection against this flavonoid. The effects of apigenin did not involve p38-MAPK or JNK1/2, and were not simply due to inhibition of PI3kinase or protein kinase CK2. These data suggest that the deregulation of the ERK1/2 pathway, due to the potentiation of ERK1/2 phosphorylation without increasing MEK1/2 phosphorylation, is involved in apigenin-induced HeLa cell death.
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Base de dados:
MEDLINE
Assunto principal:
Flavonoides
/
Morte Celular
/
Quinases de Proteína Quinase Ativadas por Mitógeno
/
Proteínas Quinases Ativadas por Mitógeno
/
Sistema de Sinalização das MAP Quinases
/
Antineoplásicos
Idioma:
En
Ano de publicação:
2004
Tipo de documento:
Article