Mitochondrial targeting of JNK/SAPK in the phorbol ester response of myeloid leukemia cells.
Cell Death Differ
; 8(8): 794-800, 2001 Aug.
Article
en En
| MEDLINE
| ID: mdl-11526432
ABSTRACT
Treatment of human U-937 myeloid leukemia cells with 12-O-tetradecanoylphorbol-13-acetate (TPA) is associated with activation of the stress-activated protein kinase (SAPK) and induction of terminal monocytic differentiation. The present studies demonstrate that TPA targets SAPK to mitochondria by a mechanism dependent on activation of protein kinase C (PKC) beta. Translocation of SAPK to mitochondria in response to TPA is associated with release of cytochrome c, caspase-3 activation and induction of apoptosis. The results show that TPA induces the association of SAPK with the mitochondrial anti-apoptotic Bcl-x(L) protein. Overexpression of Bcl-x(L) attenuated the apoptotic response to TPA treatment. Moreover, expression of Bcl-x(L) mutated at sites of SAPK phosphorylation (Thr-47, -115) was more effective than wild-type Bcl-x(L) in abrogating TPA-induced cytochrome c release and apoptosis. By contrast, expression of Bcl-x(L) had little effect on induction of the monocytic phenotype. These findings indicate that myeloid leukemia cells respond to TPA with targeting of SAPK to mitochondria and that this response contributes to terminal differentiation through the release of cytochrome c and induction of apoptosis.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Células Tumorales Cultivadas
/
Leucemia Mieloide
/
Diferenciación Celular
/
Apoptosis
/
Proteínas Quinasas Activadas por Mitógenos
/
Mitocondrias
Idioma:
En
Revista:
Cell Death Differ
Año:
2001
Tipo del documento:
Article
País de afiliación:
Estados Unidos