Targeting of the MNK-eIF4E axis in blast crisis chronic myeloid leukemia inhibits leukemia stem cell function.
Proc Natl Acad Sci U S A
; 110(25): E2298-307, 2013 Jun 18.
Article
em En
| MEDLINE
| ID: mdl-23737503
ABSTRACT
Chronic myeloid leukemia responds well to therapy targeting the oncogenic fusion protein BCR-ABL1 in chronic phase, but is resistant to treatment after it progresses to blast crisis (BC). BC is characterized by elevated ß-catenin signaling in granulocyte macrophage progenitors (GMPs), which enables this population to function as leukemia stem cells (LSCs) and act as a reservoir for resistance. Because normal hematopoietic stem cells (HSCs) and LSCs depend on ß-catenin signaling for self-renewal, strategies to specifically target BC will require identification of drugable factors capable of distinguishing between self-renewal in BC LSCs and normal HSCs. Here, we show that the MAP kinase interacting serine/threonine kinase (MNK)-eukaryotic translation initiation factor 4E (eIF4E) axis is overexpressed in BC GMPs but not normal HSCs, and that MNK kinase-dependent eIF4E phosphorylation at serine 209 activates ß-catenin signaling in BC GMPs. Mechanistically, eIF4E overexpression and phosphorylation leads to increased ß-catenin protein synthesis, whereas MNK-dependent eIF4E phosphorylation is required for nuclear translocation and activation of ß-catenin. Accordingly, we found that a panel of small molecule MNK kinase inhibitors prevented eIF4E phosphorylation, ß-catenin activation, and BC LSC function in vitro and in vivo. Our findings identify the MNK-eIF4E axis as a specific and critical regulator of BC self-renewal, and suggest that pharmacologic inhibition of the MNK kinases may be therapeutically useful in BC chronic myeloid leukemia.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Células-Tronco Neoplásicas
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Leucemia Mielogênica Crônica BCR-ABL Positiva
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Crise Blástica
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Proteínas Serina-Treonina Quinases
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Fator de Iniciação 4E em Eucariotos
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Peptídeos e Proteínas de Sinalização Intracelular
Tipo de estudo:
Prognostic_studies
Limite:
Animals
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Female
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Humans
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article