Role for the nuclear factor kappaB pathway in transforming growth factor-beta1 production in idiopathic myelofibrosis: possible relationship with FK506 binding protein 51 overexpression.
Cancer Res
; 65(8): 3281-9, 2005 Apr 15.
Article
em En
| MEDLINE
| ID: mdl-15833861
ABSTRACT
The release of transforming growth factor-beta1 (TGF-beta1) in the bone marrow microenvironment is one of the main mechanisms leading to myelofibrosis in murine models and probably in the human idiopathic myelofibrosis (IMF). The regulation of TGF-beta1 synthesis is poorly known but seems regulated by nuclear factor kappaB (NF-kappaB). We previously described the overexpression of an immunophilin, FK506 binding protein 51 (FKBP51), in IMF megakaryocytes. Gel shift and gene assays show that FKBP51's overexpression in a factor-dependent hematopoietic cell line, induces a sustained NF-kappaB activation after cytokine deprivation. This activation correlates with a low level of IkappaBalpha. A spontaneous activation of NF-kappaB was also detected in proliferating megakaryocytes and in circulating CD34(+) patient cells. In normal cells, NF-kappaB activation was only detected after cytokine treatment. The expression of an NF-kappaB superrepressor in FKBP51 overexpressing cells and in derived megakaryocytes from CD34(+) of IMF patients revealed that NF-kappaB activation was not involved in the resistance to apoptosis after cytokine deprivation of these cells but in TGF-beta1 secretion. These results highlight the importance of NF-kappaB's activation in the fibrosis development of this disease. They also suggest that FKBP51's overexpression in IMF cells could play an important role in the pathogenesis of this myeloproliferative disorder.
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Base de dados:
MEDLINE
Assunto principal:
NF-kappa B
/
Fator de Crescimento Transformador beta
/
Proteínas de Ligação a Tacrolimo
/
Mielofibrose Primária
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2005
Tipo de documento:
Article