ATRA can enhance apoptosis that is induced by Flt3 tyrosine kinase inhibition in Flt3-ITD positive cells.
Leuk Res
; 30(5): 633-42, 2006 May.
Article
em En
| MEDLINE
| ID: mdl-16473406
ABSTRACT
Among activating Flt3 mutations that have been shown in 25-30% of acute myeloid leukaemia (AML) Flt3-internal tandem duplication (ITD) mutations are predominant. We investigated the influence of all-trans-retinoic acid (ATRA) and granulocyte colony stimulating factor (G-CSF) for their effects on differentiation and apoptosis in human cell lines with different Flt3 variants (THP-1 versus MV4-11 and MOLM13) dependent on the inhibition of Flt3 tyrosine kinase by the bis(lH-2-indolyl)methanone D-65476. While myeloid differentiation was not observed in both Flt3-ITD cell lines (MV4-11 and MOLM13), we demonstrate an enhanced proapoptotic effect of D-65476 in the presence of ATRA that was restricted to the Flt3-ITD expressing cells. The combined treatment with ATRA and D-65476 also led to a pronounced down-regulation of surviv in on mRNA and protein level in Flt3-ITD but not in Flt3 wildtype expressing cells (THP-1). Surprisingly, there was no differential expression of important proteins like Bcl-X(L), Bcl-2 or Bax that might explain enhanced apoptosis. Furthermore, Akt phosphorylation after stimulation with Flt3 ligand dependent on D-65476 was not affected by pretreatment with ATRA. We suggest that regulation of inhibitors of apoptosis might play a crucial role how ATRA can increase the proapoptotic effect of Flt3 inhibitors in myeloid leukemia cells expressing Flt3-ITD. This effect can potentially be exploited for the treatment of Flt3-ITD positive acute myeloid leukemia.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tretinoína
/
Apoptose
/
Inibidores de Proteínas Quinases
/
Tirosina Quinase 3 Semelhante a fms
/
Indóis
Limite:
Humans
Idioma:
En
Revista:
Leuk Res
Ano de publicação:
2006
Tipo de documento:
Article