RESUMO
To study the hierarchical levels of stem cell targets for ABL-kinase domain mutations in CML, highly purified CD34+CD38- and CD34+CD38+ cell populations and their LTC-IC-derived progeny were analyzed in four patients at diagnosis (n=1) or in advanced phases (n=3) of their disease. In the single patient with early phase CML who later developed an Imatinib Mesylate-resistance and a Y253H mutation, no mutation was detectable in purified cell fractions analyzed at diagnosis nor in their LTC-IC-derived progeny. In contrast, in three patients in advanced phase CML, ABL-kinase mutations demonstrated in peripheral blood cells by sequencing (Q252E and M351T) were detectable in the FACS-sorted cells and became amplified in the LTC-IC-derived progeny of the primitive cells. These findings demonstrate that in late CP or advanced CML, ABL-kinase mutations occur as an intraclonal event in the primitive Ph1+ stem cell compartments with progression of this clone towards IM-resistant blast phase.
Assuntos
Proteínas de Fusão bcr-abl/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/enzimologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Fosfotransferases/genética , Piperazinas/administração & dosagem , Pirimidinas/administração & dosagem , Células-Tronco/efeitos dos fármacos , Células-Tronco/enzimologia , Antineoplásicos/administração & dosagem , Benzamidas , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Células Cultivadas , Resistência a Medicamentos/genética , Inibidores Enzimáticos/administração & dosagem , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Predisposição Genética para Doença/genética , Testes Genéticos/métodos , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Mutação , Fosfotransferases/antagonistas & inibidores , Estrutura Terciária de Proteína , Análise de Sequência de Proteína , Células-Tronco/patologia , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
BACKGROUND: Platelet activation plays an important role in arterial thrombosis and the widespread use of aspirin has reduced major events by 25% in the secondary prevention of cardiovascular diseases. However, it appears that aspirin antiplatelet effect is not uniform and 8-45% of the population are, in vitro, aspirin resistant, and it is well recognized that platelets can be activated by pathways that are not blocked by aspirin, such as adenosine diphosphate (ADP). OBJECTIVES: To investigate whether aspirin-resistant patients have a modified sensitivity to ADP-induced platelet activation MATERIALS AND METHODS: Seventy-two patients were enrolled. Platelet function was measured by the PFA-100(R) analyser; platelet GP IIb-IIIa activation by ADP 10 micro M was assessed by flow cytometry using PAC-1 MoAb. RESULTS: Using a collagen/epinephrine coated cartridge on the PFA-100(R), the prevalence of aspirin resistance was 29.2% (n=21). For aspirin-resistant patients, the collagen/ADP coated cartridge showed a closure time significantly shorter (p=0.004) compared to the sensitive and control groups. Platelets from aspirin-resistant patients bound PAC-1 significantly more (p=0.03) than the aspirin-sensitive patients and controls when activated with 10 micro M ADP. CONCLUSIONS: Platelets from aspirin-resistant patients appear to be more sensitive and activable by ADP. This hypersensitivity could provide a possible explanation for the so-called aspirin resistance, and this could justify therapeutic improvement with alternative antiplatelet agents.
Assuntos
Difosfato de Adenosina/farmacologia , Aspirina/farmacologia , Plaquetas/efeitos dos fármacos , Resistência a Medicamentos , Idoso , Angina Pectoris/sangue , Estudos de Casos e Controles , Doença da Artéria Coronariana/sangue , Fosfatase 2 de Especificidade Dupla , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ativação Plaquetária/efeitos dos fármacos , Testes de Função Plaquetária , Proteína Fosfatase 2 , Proteínas Tirosina Fosfatases/metabolismoRESUMO
Reticulated platelet count provides an estimate of thrombopoiesis in the same way as reticulocyte count is a measure of erythropoiesis. We applied thiazole orange (TO) staining, followed by fluorescence-activated flow-cytometric analysis, to platelets in whole-blood samples from normal subjects and 18 aplastic patients after chemotherapy for haematologic malignancies. The percentage of TO-positive platelets in 30 control subjects was 5.7 +/- 2.4% (mean +/- 1 SD), determining the threshold of reticulated platelet positivity as up to 10.5% (mean + 2 SD). In the 18 patients studied, the mean percentage of TO-positive platelets was 4.3 +/- 1.89% during aplasia and 23.3 +/- 9.43% during bone marrow recovery, respectively (P < 0.05). All patients had a percentage of TO-positive platelets of up to 10.5%. In comparison, mean platelet volume during bone marrow recovery increased in 12 cases of the 18 patients studied. We conclude that flow cytometric analysis of reticulated platelets is a sensitive and specific test for evaluating thrombopoiesis recovery during aplastic chemotherapy, and platelet transfusion should be reconsidered in these patients.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Medula Óssea/efeitos dos fármacos , Neoplasias Hematológicas/sangue , Neoplasias Hematológicas/tratamento farmacológico , Trombopoese/efeitos dos fármacos , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Plaquetas/efeitos dos fármacos , Plaquetas/patologia , Medula Óssea/patologia , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Valor Preditivo dos TestesRESUMO
Several publications over the last ten years have addressed the problem of genetic mutation coding platelet membrane glycoproteins and thrombotic arterial disease. The principal polymorphisms studied are those of glycoproteins GPIIIa, GPIb and the GPIa-IIa complex. The relationships of each of these polymorphisms and myocardial infarction or coronary artery disease are reported and are often subject to controversy. The polymorphism PLA2 of the GPIIIa has been shown to be a risk factor for infarction in young people, especially when associated with cigarette smoking. Its role in triggering myocardial infarction or in the severity of coronary artery disease is not so clear in the general population. Two types of polymorphism concerning the GPIb and that of the GPIa-IIa complex should also predispose to early coronary thrombotic complications. In addition, the study of these platelet polymorphisms gives a better insight into individual sensitivity to platelet antiaggregant therapy.
Assuntos
Doença da Artéria Coronariana/genética , Predisposição Genética para Doença , Infarto do Miocárdio/genética , Glicoproteínas da Membrana de Plaquetas/genética , Polimorfismo Genético , Adulto , Idade de Início , Idoso , Doença da Artéria Coronariana/etiologia , Doença da Artéria Coronariana/patologia , Humanos , Pessoa de Meia-Idade , Infarto do Miocárdio/etiologia , Infarto do Miocárdio/patologia , Fatores de RiscoRESUMO
We used a degenerate RT-PCR screen and subsequent real-time quantitative RT-PCR assays to examine the expression of HOX and TALE-family genes in 34 cases of chromosomally defined AML for which outcome data were available. AMLs with favorable cytogenetic features were associated with low overall HOX gene expression whereas poor prognostic cases had high levels. Characteristically, multiple HOXA family members including HOXA3-HOXA10 were jointly overexpressed in conjunction with HOXB3, HOXB6, MEIS1 and PBX3. Higher levels of expression were also observed in the FAB subtype, AML-M1. Spearmann correlation coefficients indicated that the expression levels for many of these genes were highly inter-related. While we did not detect any significant correlations between HOX expression and complete response rates or age in this limited set of patients, there was a significant correlation between event-free survival and HOXA7 with a trend toward significance for HoxA9, HoxA4 and HoxA5. While patients with elevated HOX expression did worse, there were notable exceptions. Thus, although HOX overexpression and clinical resistance to chemotherapy often coincide, they are not inextricably linked. Our results indicate that quantitative HOX analysis has the potential to add new information to the management of patients with AML, especially where characteristic chromosomal alterations are lacking.
Assuntos
Perfilação da Expressão Gênica/métodos , Regulação Leucêmica da Expressão Gênica , Genes Homeobox , Leucemia Mieloide/genética , Doença Aguda , Adulto , Idoso , Aberrações Cromossômicas , Cromossomos Humanos/genética , Sistemas Computacionais , Primers do DNA , Feminino , Seguimentos , Amplificação de Genes , Proteínas de Homeodomínio/biossíntese , Humanos , Leucemia Mieloide/classificação , Leucemia Mieloide/mortalidade , Masculino , Pessoa de Meia-Idade , Família Multigênica , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Curva ROC , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sobrevida , Resultado do TratamentoRESUMO
Persistence of BCR-ABL rearrangements was demonstrated by D-FISH technique in chronic myeloid leukemia (CML) patients in complete cytogenetic response (CCR) after allogeneic bone marrow transplantation (BMT) or interferon-alpha therapy (IFN-alpha). Samples from bone marrow aspirate or peripheral blood or both were analyzed by conventional cytogenetics, Southern blot, fluorescent interphase in situ hybridization (FISH), and quantitative reverse transcription polymerase chain reaction (Q-RT-PCR). In all patients, FISH detected 1% to 12% nuclei with a BCR-ABL fusion gene, whereas Q-RT-PCR were negative or weakly positive. Based on these results, we hypothesize that the BCR-ABL genomic rearrangement remains unexpressed in a small percentage of cells whatever the treatment (IFN-alpha or BMT), and this in spite of the negativity of the RT-PCR-based classical molecular remission criterion. These data corroborate those obtained by other investigators and point to the need for follow-up of CML patients in CCR over an extensive period, at the DNA level to evaluate the residual disease and at the RNA level (Q-RT-PCR) to estimate the risk of relapse and guide the therapeutic decision. Experimental models suggesting the persistence of positive BCR-ABL cells are discussed and tentative explanations of tumor "dormancy" are proposed.
Assuntos
Proteínas de Fusão bcr-abl/genética , Rearranjo Gênico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Cromossomos Humanos Par 22 , Cromossomos Humanos Par 9 , Análise Citogenética , Inativação Gênica , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Neoplasia Residual/diagnóstico , Neoplasia Residual/genética , Translocação GenéticaRESUMO
Many patients with t(8;21) AML have residual positive cells during remission. We previously developed D-FISH probes that detect both derivative chromosomes and the normal alleles. In negative controls, only 2/44,000 (0.0045%) positive signals were observed. To investigate MRD, we examined specimens from 29 patients who had initially obtained CR. In remission patients, 61% had 1-4/2000 positive cells (0.05-0.19%). Higher frequencies were found in two patients in early relapse and in one patient in early remission. However, a negative test did not exclude relapse. Since false positives were negligible and because most t(8;21) AMLs express CD34, we asked whether cell sorting combined with FISH would increase the sensitivity. In one patient, we observed that 80% of CD34+ cells were t(8;21)+ at 2 months from initial clinical and cytogenetic remission. However, by 5 months the pre- and post-sorted populations contained 0.15% and 0.06% t(8;21) cells, respectively. Whereas essentially all t(8;21) cells in the initial specimen expressed CD34, only 0.6% were subsequently CD34+. These results are consistent with in vitro assays showing that residual t(8;21) cells undergo differentiation. Thus, FISH can identify MRD in a majority of t(8;21) patients and, combined with CD34+ selection, may provide an indirect assessment of the differentiation state of residual t(8;21) cells.
Assuntos
Antígenos CD34/análise , Cromossomos Humanos Par 21 , Cromossomos Humanos Par 8 , Leucemia Mieloide/genética , Leucemia Mieloide/patologia , Doença Aguda , Separação Celular , Reações Falso-Positivas , Citometria de Fluxo , Humanos , Hibridização in Situ Fluorescente , Cariotipagem , Neoplasia Residual , Indução de Remissão , Translocação GenéticaRESUMO
The mixed lineage leukemia, MLL, gene is frequently rearranged in patients with secondary leukemia following treatment with DNA topoisomerase II inhibitors. By FISH and Southern blot analyses we identified a rearrangement in the MLL gene due to a novel t(3;11)(q28;q23) chromosomal translocation in a patient who developed AML-M5 3 years after treatment for a follicular lymphoma. Through inverse PCR, the LPP (lipoma preferred partner) gene on 3q28 was identified as the MLL fusion partner. LPP contains substantial identity to the focal adhesion protein, zyxin, and is frequently fused to HMGIC in lipomas. The breakpoint occurred in intron 8 of MLL and LPP. Two in-frame MLL-LPP transcripts, which fuse MLL exon 8 to LPP exon 9, were detected by RT-PCR, although the smaller of these contained a deletion of 120 bp from the MLL sequence. The predicted MLL-LPP fusion protein includes the A/T hook motifs and methyltransferase domain of MLL joined to the two last LIM domains of LPP. A reciprocal LPP-MLL transcript, predicted to include the proline-rich and leucine zipper motifs, and the first LIM domain of LPP were also detected by RT-PCR. In summary, LPP is a newly identified MLL fusion partner in secondary leukemia resulting from topoisomerase inhibitors. The MLL-LPP and LPP-MLL predicted proteins contain many of the features present in other MLL rearrangements.
Assuntos
Proteínas do Citoesqueleto/genética , Proteínas de Ligação a DNA/genética , Leucemia Monocítica Aguda/genética , Linfoma Folicular/genética , Segunda Neoplasia Primária/genética , Proteínas de Fusão Oncogênica/genética , Proto-Oncogenes , Fatores de Transcrição , Translocação Genética/genética , Adulto , Sequência de Aminoácidos , Sequência de Bases , Quebra Cromossômica/genética , Cromossomos Humanos Par 11/genética , Cromossomos Humanos Par 3/genética , Clonagem Molecular , Evolução Fatal , Feminino , Histona-Lisina N-Metiltransferase , Humanos , Cariotipagem , Proteínas com Domínio LIM , Leucemia Monocítica Aguda/induzido quimicamente , Linfoma Folicular/tratamento farmacológico , Dados de Sequência Molecular , Proteína de Leucina Linfoide-Mieloide , Segunda Neoplasia Primária/induzido quimicamente , RNA Mensageiro/genéticaRESUMO
BACKGROUND: Cerebral thrombosis associated with protein S deficiency is very rare and is mainly related to hereditary form of protein S deficiency. CASE REPORT: A 19-year-old girl with acute lymphoblastic leukemia presented hemianopsy within a few days after the first administration of L-asparaginase. Magnetic resonance of the brain showed a cortical infarct. A marked decrease of the level of protein S was documented. Few days later, the patient was free of symptoms and protein S level was restored to the normal suggesting that the cerebral thrombosis was caused by transient protein S deficiency induced by L-asparaginase administration. DISCUSSION: Patients with neurological complication caused by L-asparaginase should be tested for protein S and other anticoagulant deficiencies.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Asparaginase/efeitos adversos , Hemianopsia/induzido quimicamente , Embolia Intracraniana/induzido quimicamente , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Deficiência de Proteína S/induzido quimicamente , Tromboflebite/induzido quimicamente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Asparaginase/uso terapêutico , Testes de Coagulação Sanguínea , Córtex Cerebral/patologia , Infarto Cerebral/induzido quimicamente , Infarto Cerebral/diagnóstico , Diagnóstico Diferencial , Feminino , Hemianopsia/diagnóstico , Humanos , Embolia Intracraniana/diagnóstico , Imageamento por Ressonância Magnética , Deficiência de Proteína S/diagnóstico , Tromboflebite/diagnósticoAssuntos
Leucemia Mieloide Aguda/diagnóstico , Neoplasias Ovarianas/diagnóstico , Sarcoma Mieloide/diagnóstico , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Terapia Combinada , Feminino , Humanos , Cariotipagem , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/terapia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/terapia , Indução de Remissão , Sarcoma Mieloide/genética , Sarcoma Mieloide/terapiaRESUMO
In recent years, the prognosis of chronic myeloid leukemia (CML) has been greatly improved either with interferon-alpha (IFN-alpha) therapy or allogeneic bone marrow transplantation (BMT). In the present study, minimal residual disease was evaluated in 21 patients in complete cytogenetic response (CCR) after such treatments. Samples from bone marrow aspirates or peripheral blood or both were analyzed by conventional cytogenetics, Southern blot, interphase fluorescent in situ hybridization (FISH), and quantitative reverse transcription-polymerase chain reaction (Q-RT-PCR). In all patients, FISH detected 1% to 12% nuclei with a BCR-ABL fusion gene, whereas Q-RT-PCR experiments were negative or weakly positive. Based on these results, we hypothesize that the BCR-ABL genomic rearrangement persists unexpressed in nonproliferating cells whatever the treatment (IFN-alpha or BMT). These data point to the need for follow-up of CML patients in CCR over an extensive period at the DNA level (FISH) to evaluate the residual disease and at the RNA level (Q-RT-PCR) to estimate the risk of relapse. (Blood. 2000;95:404-408)
Assuntos
Antineoplásicos/uso terapêutico , Transplante de Medula Óssea , Proteínas de Fusão bcr-abl/genética , Rearranjo Gênico , Interferon-alfa/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Adulto , Idoso , Southern Blotting , Cromossomos Humanos Par 22 , Cromossomos Humanos Par 9 , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Terapia de Imunossupressão , Hibridização in Situ Fluorescente , Cariotipagem , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Translocação GenéticaRESUMO
INTRODUCTION: T-cell prolymphocytic leukemia is a rare form of mature leukemia which occurs in adults and in younger patients suffering ataxia telangiectasia. Among others, complex chromosome aberrations of chromosome 12 have been described in this disease. We searched for deletions of the 12p13 region as the result of these chromosome rearrangements. MATERIAL AND METHODS: Paired leukemic and non-leukemic cells were obtained from a series of 21 patients suffering T-cell prolymphocytic leukemia. Loss of heterozygosity was searched for by microsatellite typing using a fluorescent automated laser DNA sequencer to analyze the amplification products. Proteins were analyzed by Western blot. Southern blot analysis of one patient was conducted. RESULTS AND CONCLUSION: Loss of heterozygosity of the 12p13 region, including the ETV6 and CDKN1B genes, was detected in nine of these 21 cases (43%). Western and Southern blot analyses of one case demonstrated a biallelic deletion which did not include ETV6. Taken together, our results defined a minimal region of deletion of less than one Mb flanked by the markers b312C2T7 and D12S320, excluding ETV6 as a candidate gene. Deletion of the 12p13 region is thus a highly recurrent genetic event in T-cell prolymphocytic leukemia.
Assuntos
Centrômero/genética , Deleção Cromossômica , Cromossomos Humanos Par 12 , Proteínas de Ligação a DNA/genética , Leucemia Prolinfocítica/genética , Leucemia de Células T/genética , Perda de Heterozigosidade , Proteínas Repressoras/genética , Mapeamento Cromossômico , DNA de Neoplasias/sangue , DNA de Neoplasias/isolamento & purificação , Marcadores Genéticos , Humanos , Repetições de Microssatélites , Fosfoproteínas/genética , Proteínas Proto-Oncogênicas c-ets , Mapeamento por Restrição , Transcrição Gênica , Variante 6 da Proteína do Fator de Translocação ETSRESUMO
We report a case of acute myeloid leukemia FAB-type 2 with a translocation t(15;17)(q22;q12) On the basis of the cytological findings, a translocation t(8;21)(q22;q22) was suspected. FISH analyses using specific probes for t(15;17) and t(8;21) detected both PML/RARalpha and AML1/ETO rearrangements in a few percentage of cells. This case demonstrates the complexities that may occur between cytology and cytogenetic findings and the usefulness of FISH methods to detect an AML1/ETO rearrangement only suspected by cytological examination of bone marrow smears.
Assuntos
Cromossomos Humanos Par 15 , Cromossomos Humanos Par 17 , Leucemia Mieloide Aguda/genética , Proteínas de Neoplasias/genética , Proteínas de Fusão Oncogênica/genética , Receptores do Ácido Retinoico/genética , Fatores de Transcrição/genética , Translocação Genética , Adulto , Medula Óssea/patologia , Subunidade alfa 2 de Fator de Ligação ao Core , Feminino , Rearranjo Gênico , Humanos , Hibridização in Situ Fluorescente , Leucemia Mieloide Aguda/patologia , Proteína 1 Parceira de Translocação de RUNX1 , Proteínas Recombinantes de Fusão/genética , Receptor alfa de Ácido RetinoicoRESUMO
The occurrence of abnormally low serum immunoglobulin (Ig) levels is well-known in B chronic lymphocytic leukemia (CLL), but published data on IgG subclass levels are virtually absent. We measured serum IgG subclass levels in 52 B CLL outpatients, most in stage A and untreated, using an indirect immunoenzymatic assay with monoclonal antibodies. Mean levels of all Ig isotypes were lower than in normal controls in the whole group of patients, except for IgG2 in those studied at diagnosis. Levels of IgG1, IgG2, IgA, and IgM were lower in patients with a long disease duration than in those studied earlier. IgG subclass deficiencies occurred in 54% of cases and the most frequently affected isotype was IgG1. Every possible combination of IgG subclass and Ig class deficiencies from the selective deficiency of a single subclass to a combined deficiency of all isotypes was observed. This marked heterogeneity argues against the occurrence of isolated defects of one of the cytokines involved in Ig switching as a cause of hypoimmunoglobulinemia in CLL.
Assuntos
Deficiência de IgG/sangue , Imunoglobulina G/sangue , Imunoglobulina G/classificação , Isotipos de Imunoglobulinas/sangue , Leucemia Linfocítica Crônica de Células B/imunologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Deficiência de IgG/etiologia , Leucemia Linfocítica Crônica de Células B/sangue , Leucemia Linfocítica Crônica de Células B/complicações , Masculino , Pessoa de Meia-IdadeRESUMO
T-prolymphocytic leukaemia (T-PLL) is a rare disorder with a poor outcome. Presentation features were studied in 78 T-PLL cases. Although 53 patients (group A) presented with typical progressive disease including rapidly increasing leucocytosis. 25 patients (group B) experienced an initial indolent clinical course with stable moderate leucocytosis. The morphology and antigenic profile of abnormal cells were similar in both groups, except for a lower incidence of CD45RO+ CD45RA- pattern in group B. A high incidence of inv(14)(q11;q32), t(14;14)(q11;q32) and i(8)(q10) chromosomal abnormalities were found in both groups. After an initial indolent phase (median 33 months; 6-103 months), 16 group B patients progressed to an aggressive stage with clinical and laboratory features similar to group A. Moreover, median survival after progression was short in both groups. In conclusion, T-PLL may start as an indolent disease similar to that reported in ataxia telangectasia. In this rare genetic disorder, some patients develop stable T-cell clones which progress toward T-PLL-like leukaemia. Moreover, ATM gene mutations have been reported in T-PLL. Thus, both diseases are likely to be closely related.
Assuntos
Leucemia Prolinfocítica de Células T/diagnóstico , Leucemia Prolinfocítica/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Aberrações Cromossômicas , Progressão da Doença , Feminino , Seguimentos , Humanos , Imunofenotipagem , Leucemia Prolinfocítica/imunologia , Leucemia Prolinfocítica/patologia , Leucemia Prolinfocítica de Células T/imunologia , Leucemia Prolinfocítica de Células T/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
Cytogenetic, interphase fluorescent in situ hybridization (FISH) and RT-PCR methods were used to study minimal residual disease in peripheral blood stem cells collected for autografting in three chronic myeloid leukemia (CML) patients in sustained complete cytogenetic remission after treatment with interferon alpha (IFNalpha). Karyotypic analysis failed to reveal Ph-positive metaphases. FISH detected 9-16% nuclei with a BCR-ABL fusion gene, contrasting with RT-PCR, performed in two cases, which was negative in one case and weakly positive in the other. RT-PCR was also subsequently weakly positive in the third patient. This discrepancy suggests that the BCR-ABL genomic rearrangement persists unexpressed in quiescent cells. These preliminary results, which need to be confirmed in larger series, suggest that monitoring residual disease in CML should be performed both at DNA and RNA levels. Moreover, autografting following IFNalpha therapy should be considered with caution because of the persistence of the BCR-ABL genomic rearrangement in a sizeable proportion of the cells.
Assuntos
Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Proteínas de Fusão bcr-abl/genética , Interferon-alfa/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Adulto , Antineoplásicos/administração & dosagem , Fusão Gênica Artificial , Feminino , Rearranjo Gênico , Humanos , Hidroxiureia/administração & dosagem , Hibridização in Situ Fluorescente , Interferon-alfa/administração & dosagem , Masculino , Pessoa de Meia-Idade , Cromossomo Filadélfia , Reação em Cadeia da Polimerase , Indução de RemissãoRESUMO
Abnormalities of the short arm of chromosome 12 are nonrandom events in T cell prolymphocytic leukemia (T-PLL). Fluorescence in situ hybridization (FISH) studies were performed in three patients with T-PLL and one patient with T cell peripheral lymphoma and rearrangement of 12p. Whereas the rearrangements of 12p were different in the four patients, a breakpoint centromeric to the ETV6 gene was present in the three T-PLL patients. In addition, loss of heterozygosity for a chromosomal segment telomeric to ETV6 with loss of the RAD52 locus was also shown by FISH studies. In contrast, the breakpoint was telomeric to ETV6 in the patient with peripheral lymphoma.
Assuntos
Aberrações Cromossômicas , Cromossomos Humanos Par 12 , Leucemia Prolinfocítica/genética , Leucemia de Células T/genética , Idoso , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Hibridização in Situ Fluorescente , Masculino , Pessoa de Meia-IdadeRESUMO
The Bcr-Abl fusion protein plays a crucial role in the initiation and maintenance of chronic myelogenous leukemia (CML). However, additional events are necessary for the transition from the chronic phase to the terminal phase of the disease. To identify genes involved in the disease progression, we constructed a subtractive library from enriched K562 cell mRNA. We obtained 1084 cDNA clones. After a specific hybridization of these clones with a cDNA probe from either chronic phase or K562 cells, 43 clones which present a differential hybridization level have been selected. Among them, several clones corresponded to ribosomal protein genes showing an increased transcription level during the blast crisis. We observed variations in the expression of a cellular adhesion molecule, a laminin-binding protein. An increased transcription level of the MAZ gene has been shown in the terminal phase of the disease. This gene encodes a protein that regulates the transcription of myc.
Assuntos
Regulação Neoplásica da Expressão Gênica , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Transcrição Gênica , Crise Blástica , Proteínas de Transporte/biossíntese , Moléculas de Adesão Celular/biossíntese , Primers do DNA , Proteínas de Ligação a DNA , Progressão da Doença , Biblioteca Gênica , Humanos , Laminina/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/sangue , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Contagem de Leucócitos , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas c-myc/biossíntese , RNA Mensageiro/biossíntese , Proteínas Ribossômicas/biossíntese , Fatores de Transcrição/biossíntese , Células Tumorais CultivadasRESUMO
BACKGROUND: In this study, we evaluated the in vitro bone marrow toxicity of two lipid emulsions containing either long-chain triglycerides (LCT) or a mixture of medium-chain triglycerides (MCT) and LCT. METHODS: Bone marrow cells were obtained from six healthy subjects and were cultured for 14 days after a 24-hour preincubation with various concentrations (from 0 to 10 mg/mL) of LCT- and LCT/MCT-based lipid emulsions. RESULTS: Compared with controls (no preincubation with lipid emulsion), both lipid emulsions significantly inhibited by 50% to 70% colony formation of all the human bone marrow cells cultured from a triglyceride concentration of 0.5 mg/mL (p < .05). Erythroid burst-forming unit (BFU-E) formation was significantly more inhibited with LCT/MCT emulsion than with LCT emulsion (p < .05). The inhibition of granulocyte-macrophage colony-forming unit (GM-CFU) and mixed granulocyte-erythrocyte-monocyte-megakaryocyte colony-forming unit (GEMM-CFU) formation did not significantly differ with the two emulsions. CONCLUSIONS: Both LCT- and LCT/MCT-based lipid emulsions strongly inhibit colony formation by human bone marrow cells. BFU-E colony formation is more sensitive to LCT/MCT inhibition than to LCT.
Assuntos
Células da Medula Óssea/efeitos dos fármacos , Triglicerídeos/química , Triglicerídeos/farmacologia , Adulto , Morte Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Emulsões , Células Precursoras Eritroides/efeitos dos fármacos , Feminino , Células-Tronco Hematopoéticas/efeitos dos fármacos , Humanos , Técnicas In Vitro , Masculino , Fatores de TempoRESUMO
Glutathione S transferase theta 1 (GSTT1) is implicated in the detoxification of different substances, including carcinogens. Recently, an increased incidence of GSTT1 null genotype was found in myelodysplastic syndromes (MDS) by comparison with a control population. We analyzed GSTT1 gene by PCR in 174 MDS cases and 100 controls. The incidence of GSTT1 null genotype was 22% in MDS in 19% in controls (P = 0.53). The incidence of GSTT1 null genotype in MDS did not differ according to gender, FAB classification, karyotype and whether MDS were therapy related or 'de novo'. In 86 of the de novo cases, data on previous occupational and environmental exposure to a list of 170 substances were available. In those MDS patients, a significantly lower frequency of GSTT1 null genotype was seen in cases with previous jobs exposed to chemicals, and with previous exposure to mineral dusts and exhaust gases. A lower frequency (but with only borderline significance) was seen in MDS patients who had been coal miners and those who had been exposed to any of the 70 substances analyzed. Overall, GSTT1 null genotype occurred at a similar incidence (19%) in controls and in MDS cases previously exposed to any substance, but tended to be higher in unexposed MDS patients (40%, P = 0.07). Our results do not confirm the higher incidence of GSTT1 null genotype observed in MDS. The lower incidence of GSTT1 null genotype in MDS cases exposed to some compounds previously found associated with MDS is apparently unexpected. However, it could be explained by the fact that GSTT1 enzyme, which has a detoxification role for some compounds, could also have an activating role for other substances, including solvents.