Constant activation of the RAF-MEK-ERK pathway as a diagnostic and therapeutic target in hairy cell leukemia.
Haematologica
; 98(4): 635-9, 2013 Apr.
Article
en En
| MEDLINE
| ID: mdl-23349307
The BRAF-V600E mutation defines genetically hairy cell leukemia among B-cell leukemias and lymphomas. In solid tumors, BRAF-V600E is known to aberrantly activate the oncogenic MEK-ERK pathway, and targeted BRAF and/or MEK inhibitors have shown remarkable efficacy in clinical trials in melanoma patients. However, the MEK-ERK pathway status in hairy cell leukemia has not been thoroughly investigated. We assessed phospho-ERK expression in 37 patients with hairy cell leukemia and 44 patients with neoplasms mimicking hairy cell leukemia (40 splenic marginal zone lymphoma, 2 hairy cell leukemia-variant and 2 splenic lymphoma/leukemia unclassifiable) using immunohistochemistry on routine biopsies and/or Western blotting on purified leukemic cells, and correlated the phospho-ERK status with the BRAF-V600E mutation status. Besides confirming the constant presence of BRAF-V600E in all patients with hairy cell leukemia, we observed ubiquitous phospho-ERK expression in this malignancy. Conversely, all 44 cases with neoplasms mimicking hairy cell leukemia were devoid of BRAF-V600E and none expressed phospho-ERK. Furthermore, the two exceptionally rare cases of non-hairy cell leukemia unclassifiable chronic B-cell neoplasms previously reported to be BRAF-V600E(+) on allele-specific polymerase chain reaction lacked phospho-ERK expression as well, suggesting the presence of the mutation in only a small part of the leukemic clone in these cases. In conclusion, our findings support the use of phospho-ERK immunohistochemistry in the differential diagnosis between hairy cell leukemia and its mimics, and establish the MEK-ERK pathway as a rational therapeutic target in this malignancy.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Leucemia de Células Pilosas
/
Proteína Quinasa 1 Activada por Mitógenos
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Sistema de Señalización de MAP Quinasas
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Proteínas Proto-Oncogénicas B-raf
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Proteína Quinasa 3 Activada por Mitógenos
Tipo de estudio:
Diagnostic_studies
Límite:
Humans
Idioma:
En
Revista:
Haematologica
Año:
2013
Tipo del documento:
Article
País de afiliación:
Italia
Pais de publicación:
Italia