RESUMO
A t(11;20)(p15;q11) is a rare but recurrent chromosomal aberration, reported in one case of polycythemia vera and a few cases of de novo acute myelocytic leukemia (AML) and therapy-related myelodysplastic syndrome (t-MDS). In t-MDS cases, the translocation resulted in the NUP98/TOP1 fusion transcript. The NUP98 gene has been suggested as the target for therapy-related malignancies. The reciprocal TOP1/NUP98 chimera, however, has not yet been encountered. We report a further case of de novo AML, subtype M2 in the French-American-British (FAB) classification, in which the reverse-transcriptase polymerase chain reaction (RT-PCR) revealed the NUP98/TOP1 chimera and also, for the first time, its reciprocal TOP1/NUP98. The literature review disclosed that, among six cases of de novo AML with t(11;20), the NUP98 gene was shown to be involved in one case and the NUP98/TOP1 chimera was detected in another. The translocation seems to be frequently associated with the FAB M2 subtype, younger age, hyperleukocytosis, and poor prognosis; thus, this translocation may identify a subset of not-therapy-related AML patients with shared clinical features.
Assuntos
Cromossomos Humanos Par 11 , Cromossomos Humanos Par 20 , Leucemia Mieloide Aguda/genética , Translocação Genética , Adolescente , Sequência de Aminoácidos , Sequência de Bases , Análise Citogenética , DNA Topoisomerases Tipo I/genética , Feminino , Humanos , Cariotipagem , Leucemia Mieloide Aguda/classificação , Dados de Sequência Molecular , Complexo de Proteínas Formadoras de Poros Nucleares/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Deleção de SequênciaRESUMO
BACKGROUND: Up now no firm conclusions can be drawn on the genotoxicity of Extremely Low Frequency (ELF) Magnetic Fields (MF) in exposed workers: both an increase in chromosomal aberrations (CA) and micronuclei (MN) or no effects were observed in substation workers, while a slight increase in CA, but not in sister chromatid exchanges (SCE) or MN was reported in linesman; an increase in CA was observed in cable splicers and, more recently, in train engine drivers, but results have not been replicated. OBJECTIVES: Objective of the study was an evaluation of possible genotoxicity of occupational exposure to ELF-MF. METHODS: SCE, high-frequency cells (HFC) and SCE in HFC were measured in peripheral blood lymphocytes from 70 workers exposed to various levels of ELF-MF in different occupations, not involving exposure to known mutagens or carcinogens. In all participants, individual ELF-MF exposure was measured throughout the whole work-shift for 3 consecutive days by personal monitoring. RESULTS: Time Weighted Average (TWA) values of ELF-MF in the whole group ranged from 0.01 to 3.48 microT; the geometric mean was 0.19 mT, and only 3 subjects exceeded 2 microT. According to the individual TWA exposure, subjects were divided into two groups: low exposed (< or = 0.2 microT) and highly exposed (> 0.2 microT). The mean values of SCE, HFC and SCE in HFC were compared between low and highly exposed: no significant differences were observed. The result was further tested by selection and comparison of workers exposed up to 0.1 microT vs. exposed > 0.4 microT only, i.e. excluding intermediate exposures: again no difference in genotoxicity indices was observed. Also multivariate analysis did not show any correlation between individual ELF-MF exposure and genotoxicity indices. CONCLUSIONS: The results of our study do not give any support to the hypothesis that occupational exposure to ELF-MF up to about 2 microT, i.e. at the levels currently found in most workplaces, can exert a genotoxic effect in workers.
Assuntos
Campos Eletromagnéticos/efeitos adversos , Exposição Ocupacional , Troca de Cromátide Irmã/efeitos da radiação , Adulto , Consumo de Bebidas Alcoólicas/sangue , Consumo de Bebidas Alcoólicas/genética , Contagem de Células , Células Cultivadas/ultraestrutura , Feminino , Humanos , Linfócitos/ultraestrutura , Masculino , Pessoa de Meia-Idade , Ocupações , Fumar/sangue , Fumar/genética , VacinaçãoRESUMO
The multiple cancers (MC) phenotype represents an intriguing entity from both the clinical and the biomolecular points of view. Multiple cancers can arise in a patient either synchronously or metachronously and are frequently detected in hereditary disorders. Here we report the clinical and cytogenetic characterization of 48 patients developing at least three malignancies outside the context of a known genetic condition and 30 control individuals. Medical and pathology reports were registered, blood was collected for cytogenetic studies, and the standard G-banding technique was used for chromosomal analysis of the lymphocyte cultures. Chromosomal analysis of the peripheral blood cultures revealed high cytogenetic instability in 83% of patients' karyotypes that displayed structural rearrangements most often involving chromosomes X, 1, 6, and 7. Peculiar telomeric associations and marker chromosomes were detected in patients with a suspected cancer family history. The MC condition can be observed over a wide clinical range, which includes either apparently sporadic cases or families with a strong history of tumors. These findings indicate that Xq, 6p, and 7q are likely to harbor genes of importance in cancer development, and the present cytogenetic mapping may be crucial for further molecular genetic investigations to recognize a predictive cytogenetic signature useful to detect patients with a high risk of multiple malignancies.
Assuntos
Aberrações Cromossômicas , Neoplasias Primárias Múltiplas/genética , Segunda Neoplasia Primária/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Humanos , Cariotipagem , Masculino , Pessoa de Meia-Idade , Neoplasias Primárias Múltiplas/patologia , Segunda Neoplasia Primária/patologiaRESUMO
In this study, we used single nucleotide polymorphism and comparative genomic hybridization array to study DNA copy number changes and loss of heterozygosity for 28 patients affected by Sézary syndrome (SS), a rare form of cutaneous T-cell lymphoma (CTCL). Our data identified, further confirming previous studies, recurrent losses of 17p13.2-p11.2 and 10p12.1-q26.3 occurring in 71% and 68% of cases, respectively; common gains were detected for 17p11.2-q25.3 (64%) and chromosome 8/8q (50%). Moreover, we identified novel genomic lesions recurring in >30% of tumors: loss of 9q13-q21.33 and gain of 10p15.3-10p12.2. Individual chromosomal aberrations did not show a significant correlation with prognosis; however, when more than three recurrent chromosomal alterations (gain or loss) were considered, a statistical association was observed using Kaplan-Meier survival analysis. Integrating mapping and transcriptional data, we were able to identify a total of 113 deregulated transcripts in aberrant chromosomal regions that included cancer-related genes such as members of the NF-kappaB pathway (BAG4, BTRC, NKIRAS2, PSMD3, and TRAF2) that might explain its constitutive activation in CTCL. Matching this list of genes with those discriminating patients with different survival times, we identify several common candidates that might exert critical roles in SS, such as BUB3 and PIP5K1B. Altogether, our study confirms and maps more precisely the regions of gain and loss and, combined to transcriptional profiles, suggests a novel set of genes of potential interest in SS.
Assuntos
Aberrações Cromossômicas , Dosagem de Genes , Perfilação da Expressão Gênica , Perda de Heterozigosidade , Proteínas de Neoplasias/genética , Síndrome de Sézary/genética , Síndrome de Sézary/patologia , Cromossomos Humanos/genética , Hibridização Genômica Comparativa , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Polimorfismo de Nucleotídeo Único/genética , Prognóstico , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Taxa de SobrevidaRESUMO
Isolated extramedullary relapse (IEMR) is a pattern of acute myeloid leukemia (AML) relapse post-allogeneic bone marrow transplantation (alloBMT). Less is known about IEMR post-autologous BMT (autoBMT) and about factors associated with IEMR. We report a case of a woman with M4 AML who experienced IEMR post-autoBMT and review the related literature. Seventy-two alloBMT and 3 autoBMT patients, including ours, were identified. The review suggests that an M2 or M4 French-American-British (FAB) phenotype, intermediate cytogenetic risk group, and chromosome 8 abnormalities are more frequently associated with the occurrence of IEMR. IEMR occurs earlier in autoBMT than in alloBMT. Combined treatment with radiation and high-dose chemotherapy may be effective. When we searched the European Bone Marrow Transplant Registry (EBMTR) database, we found the incidence of IEMR to be statistically greater in alloBMT than in autoBMT (11% vs. 6%; P = 0.02), but no correlations have been found with the conditioning transplant regimen used. A closer follow-up, including body and central nervous system scan, should be considered in patients who are undergoing BMT presenting with several IEMR-associated factors.
Assuntos
Transplante de Medula Óssea , Leucemia Mieloide Aguda/terapia , Idoso , Antimetabólitos Antineoplásicos/administração & dosagem , Sistema Nervoso Central/diagnóstico por imagem , Aberrações Cromossômicas , Cromossomos Humanos Par 8 , Terapia Combinada , Citarabina/administração & dosagem , Evolução Fatal , Feminino , Humanos , Leucemia Mieloide Aguda/complicações , Leucemia Mieloide Aguda/diagnóstico por imagem , Radiografia , Recidiva , Sistema de Registros , Transplante Autólogo , Transplante HomólogoRESUMO
A 77-year-old female with polycythemia vera (PV) showed a sudden, typical chronic myeloid leukaemia (CML), 8 yr after the initial diagnosis, and an intermittent treatment with hydroxyurea (0.5-1 g/d) and phlebotomies. At PV diagnosis, the Ph chromosome was negative and no bcr-abl rearrangement was observed; they were both revealed positive at CML onset. Transition of PV to CML is very rare; only seven substantiated cases had been reported in the literature up until now (six from 1964 to 1993). All patients but one received (32)P or alkylating agents for PV treatment. The pathogenetic mechanisms are briefly discussed.