RESUMO
Expression of the gene Wilms tumor 1 (WT1) has been suggested as a marker of minimal residual disease in acute myeloid leukemia (AML), but literature data are not without controversy. Our aim was to assess the presence, magnitude and temporal changes of WT1 expression as prognostic factors. 60 AML patients were followed until death or the end of the 6-year observation period. Blood samples were taken at diagnosis, post-induction, during remission and in case of a relapse. Using quantitative real-time PCR, we determined WT1 expression from each sample, normalized it against the endogenous control gene glyceraldehyde 3-phosphate dehydrogenase (GAPDH), and classified samples as negative, moderately positive or highly positive. We divided the patients into groups based on detected WT1 expression values, illustrated overall and disease-free survival on Kaplan-Meier curves, and compared differences between each group by the logrank test. Disappearance of WT1-positivity during chemotherapy had a favorable effect on survival. Interestingly, no difference was seen between the survivals of WT1-positive subgroups that expressed moderate or high levels of WT1 mRNA. A 1-log decrease in WT1 expression without becoming negative did not affect prognosis, either. Our results suggest that defining a cut-off value for WT1-positivity, rather than just using logarithmic figures of changes in gene expression, might have prognostic use in post-induction AML patients. We encourage further, larger-scale studies.
Assuntos
Biomarcadores Tumorais/genética , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Proteínas WT1/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Feminino , Citometria de Fluxo , Seguimentos , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasia Residual/tratamento farmacológico , Neoplasia Residual/genética , Neoplasia Residual/patologia , Prognóstico , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Taxa de Sobrevida , Adulto JovemRESUMO
The Wilms tumor 1 (WT1) gene has a complex role as a transcriptional regulator, acting as tumor suppressor or oncogene in different malignancies. The prognostic role of its overexpression has been well-studied in leukemias, especially acute myeloid leukemia (AML), but not in lymphomas. For the first time to our knowledge, we present a study demonstrating the correlation of WT1 expression and survival in various non-Hodgkin lymphomas. We also studied the prognostic implications of WT1 overexpression in adult acute lymphoblastic leukemia (ALL). In our sample of 53 patients--25 with diffuse large B-cell lymphoma (DLBCL), 8 with mantle cell lymphoma (MCL), 9 with peripheral T-cell lymphoma (PTCL), 2 with Burkitt's lymphoma, 2 with mucosa-associated lymphoid tissue (MALT) lymphoma, and 7 with B-cell ALL--, we measured WT1 mRNA from blood samples by quantitative RT-PCR, and divided the patients into subgroups based on the level of expression. Kaplan-Meier survival curves were drawn and compared using the logrank test. In the sample of DLBCL patients, the difference in overall and disease-free survival between WT1-positive and negative subgroups was significant (p = 0.0475 and p = 0.0004, respectively), and in a few observed cases, a sudden increase in WT1 expression signified a relapse soon followed by death. Disease-free survival curves in MCL and ALL were similarly suggestive of a potential role played by WT1. In PTCL, though WT1-positivity was detected in 4 out of 9 cases, it did not seem to affect survival. The few cases of MALT and Burkitt's lymphoma all proved to be WT1-negative.
Assuntos
Biomarcadores Tumorais/genética , Linfoma não Hodgkin/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proteínas WT1/genética , Adulto , Idoso , Estudos de Casos e Controles , Terapia Combinada , Feminino , Seguimentos , Humanos , Linfoma não Hodgkin/classificação , Linfoma não Hodgkin/mortalidade , Linfoma não Hodgkin/terapia , Masculino , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Prognóstico , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Taxa de Sobrevida , Adulto JovemRESUMO
The Wilms tumor 1 (WT1) gene is currently in focus by pediatric nephrologists as its mutations are associated with nephrotic syndrome, especially as part of complex clinical entities like Denys-Drash or Frasier syndrome. Renal failure may also develop in young WAGR patients, whose condition is attributed to a deletion at chromosomal region 11p13. However, only limited data exist on WT1 microdeletions. A 30-year-old male patient, with a history of genital malformations, a Wilms tumor manifested during the treatment of acute lymphoid leukemia (ALL) at the age of 4, and a cerebellar angioblastoma, was referred with proteinuria and a reduced glomerular filtration rate (GFR). Kidney biopsy revealed FSGS. Although all WT1 exons were amplified with polymerase chain reaction (PCR) and sequenced, none of them showed a mutation. However, an formalin-fixed, paraffin- embedded (FFPE) tissue sample of the patient's childhood Wilms tumor showed WT1- positivity restricted to the renal tumor cells, so the WT1 gene was investigated further. Using quantitative reverse transcription PCR (qRT-PCR), the gene was found to be present in only one copy in the patient's genomic DNA sample, while both copies were detected in both parents. In the patient's sister, the proximal region of WT1 was shown to have an extra copy. Evidence suggests that a heterozygous microdeletion of the gene WT1 is responsible for the patient's disease. It seems reasonable to assume a possible abnormality affecting meiotic crossing over at the WT1 locus in one of the parents.