Presence of heterozygous ATM deletion may not be critical in the primary response of chronic lymphocytic leukemia cells to fludarabine.
Eur J Haematol
; 82(2): 133-42, 2009 Feb.
Article
em En
| MEDLINE
| ID: mdl-19018867
ABSTRACT
OBJECTIVES:
Abnormalities of the TP53 or ATM, cooperating tumor-suppressor genes, significantly worsen the treatment options for chronic lymphocytic leukemia (CLL) patients. Although the aberrations seem to be mutually exclusive in this leukemia, inactivation of the former gene leads to worse prognosis. We tested the in vitro sensitivity of the CLL samples with heterozygous ATM deletion to fludarabine and combination of fludarabine and rituximab; the responses were compared with the TP53-abnormal and wild-type (wt) cells to delimitate relative significance of ATM deletion.METHODS:
In vitro analysis was performed on fifty-nine characterized CLL samples using viability assay WST-1. Western blot and real-time RT-PCR were used to monitor the activation of the ATM/p53 pathway. RESULTS ANDCONCLUSIONS:
At the clinically relevant concentration of fludarabine, TP53-abnormal samples exhibited markedly higher resistance to fludarabine than the remaining CLL samples (P = 0.012); cohort with ATM deletion was not more resistant than wt cells. A similar induction of the p53 protein and its downstream target genes PUMA and BAX in ATM-deleted and wt cells confirmed that the former subgroup has preserved a critical pro-apoptotic response. Proportions of the samples, which had been sensitized to fludarabine by rituximab pretreatment, were insignificantly lower (P = 0.22) in the TP53-abnormal and ATM-deleted subgroups compared to the wt cases (30%; 29%; 50%, respectively). The presence of ATM (11q22-23) deletion in the CLL cells should not be considered an indication of resistance to fludarabine or its combination with rituximab.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Vidarabina
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Leucemia Linfocítica Crônica de Células B
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Proteínas Serina-Treonina Quinases
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Deleção de Genes
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Proteínas de Ciclo Celular
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Proteínas Supressoras de Tumor
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Proteínas de Ligação a DNA
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Antineoplásicos
Limite:
Humans
Idioma:
En
Revista:
Eur J Haematol
Assunto da revista:
HEMATOLOGIA
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
República Tcheca