Modes of activation of mitogen-activated protein kinases and their roles in cepharanthine-induced apoptosis in human leukemia cells.
Cell Signal
; 14(6): 509-15, 2002 Jun.
Article
en En
| MEDLINE
| ID: mdl-11897491
ABSTRACT
We previously showed that cepharanthine (CEP), a biscoclaurine alkaloid, induces caspase-dependent and Fas-independent apoptosis in Jurkat and K562 human leukemia cells. In the present study, we investigated the effect of CEP on three groups of human mitogen-activated protein kinases (MAPKs) in relation to CEP-induced apoptosis. CEP, at the concentration required for and at the time of induction of apoptosis, activated MAPKs p38 in both Jurkat and K562 cells and activated extracellular signal-regulated kinases (ERKs) only in K562 cells. However, CEP treatment did not trigger c-Jun NH(2)-terminal kinases (JNKs) activation. CEP increased the expression and phosphorylation levels of c-Jun and ATF-2 transcription factors. zVAD-fmk, a general caspase inhibitor, did not inhibit CEP-triggered p38 activation in Jurkat and K562 cells or ERK activation in K562 cells. Unexpectedly, pretreatment with a specific p38 inhibitor, SB203580, promoted CEP-induced apoptosis and caspase activation in Jurkat and K562 cells, whereas pretreatment with an MEK-1 inhibitor PD98059 inhibited CEP-induced apoptosis and caspase activation in K562 cells. A selective tyrosine kinase inhibitor, herbimycin A, which completely inhibited CEP-triggered ERKs activation, clearly promoted CEP-induced c-Jun expression and phosphorylation. Our results suggest that each of the three groups of MAP family members is uniquely involved in the CEP-mediated signal cascades in two different leukemia cell lines for inducing/regulating caspase activation and DNA fragmentation.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Leucemia
/
Apoptosis
/
Proteínas Quinasas Activadas por Mitógenos
/
Alcaloides
/
Antineoplásicos Fitogénicos
Límite:
Humans
Idioma:
En
Revista:
Cell Signal
Año:
2002
Tipo del documento:
Article
País de afiliación:
Japón