Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 98
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Ann Oncol ; 30(1): 85-95, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30371735

RESUMO

Background: Early cancer diagnosis might improve survival rates. As circulating tumor DNA (ctDNA) carries cancer-specific modifications, it has great potential as a noninvasive biomarker for detection of incipient tumors. Patients and methods: We collected cell-free DNA (cfDNA) samples of 1002 elderly without a prior malignancy, carried out whole-genome massive parallel sequencing and scrutinized the mapped sequences for the presence of (sub)chromosomal copy number alterations (CNAs) predictive for a malignancy. When imbalances were detected, 6-monthly clinical follow-up was carried out. Results: In 3% of participants chromosomal imbalances were detected. Follow-up analyses, including whole-body MRI screening, confirmed the presence of five hematologic malignancies: one Hodgkin lymphoma (HL), stage II; three non-HL (type chronic lymphocytic leukemia, Rai I-Binet A; type SLL, stage III; type mucosa-associated lymphoid tissue, stage I) and one myelodysplastic syndrome with excess blasts, stage II. The CNAs detected in cfDNA were tumor-specific. Furthermore, one case was identified with monoclonal B-cell lymphocytosis, a potential precursor of B-cell malignancy. In 24 additional individuals, CNAs were identified but no cancer diagnosis was made. For 9 of them, the aberrant cfDNA profile originated from peripheral blood cells. For 15 others the origin of aberrations in cfDNA remains undetermined. Conclusion(s): Genomewide profiling of cfDNA in apparently healthy individuals enables the detection of incipient hematologic malignancies as well as clonal mosaicism with unknown clinical significance. CNA screening of cellular DNA of peripheral blood in elderly has established that clonal mosaicism for these chromosomal anomalies predicts a 5- to 10-fold enhanced risk of a subsequent cancer. We demonstrate that cfDNA screening detects CNAs, which are not only derived from peripheral blood, but even more from other tissues. Since the clinical relevance of clonal mosaics in other tissues remains unknown, long-term follow-up is warranted. Taken together, this study demonstrates that genomewide cfDNA analysis has potential as an unbiased screening approach for hematological malignancies and premalignant conditions.


Assuntos
DNA Tumoral Circulante/análise , Variações do Número de Cópias de DNA , DNA de Neoplasias/análise , Detecção Precoce de Câncer/métodos , Neoplasias/diagnóstico , Neoplasias/genética , Sequenciamento Completo do Genoma/métodos , Idoso , Idoso de 80 Anos ou mais , DNA Tumoral Circulante/genética , Estudos de Coortes , DNA de Neoplasias/genética , Feminino , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/sangue , Prognóstico
2.
Ann Hematol ; 98(6): 1421-1426, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30919072

RESUMO

Hydroxyurea (HU) resistance or intolerance occurs in 15 to 24% of patients with polycythemia vera (PV). Resistance to HU is associated with a shortened life expectancy, intolerance has no prognostic value. We assessed the occurrence of HU resistance or intolerance comparing the original (ELNo) versus the modified European Leukemia Net (ELNm) criteria as applied in recent large clinical trials including PV patients. We retrospectively analyzed 106 patients with PV treated with HU at the University Hospitals of Leuven between 1990 and 2016 for occurrence of HU resistance/intolerance when using both ELNo as ELNm. After a mean duration of treatment of 5.1 years, when applying the ELNo 20.7% of patients had shown resistance or intolerance to HU in comparison to 39.6% when using the ELNm. When using the ELNo 4.7% of patients were resistant to HU versus 23.6% when applying the ELNm. In total, 16.0% of patients were HU intolerant. This rate was identical when using both ELNo and ELNm. 20.7% of PV patients were considered as HU-resistant or intolerant when using the original ELN criteria. However, when applying the modified ELN criteria 39.6% of PV patients were resistant or intolerant to HU. In our hands, no patient received a minimum dose of 2 g HU a day, as such the ELNm seem better adapted for daily clinical use. However, the prognostic value of HU-resistance in PV, when defined by the ELNm, still needs to be confirmed.


Assuntos
Resistência a Medicamentos , Hidroxiureia/uso terapêutico , Policitemia Vera/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Febre/induzido quimicamente , Seguimentos , Humanos , Hidroxiureia/efeitos adversos , Hidroxiureia/farmacologia , Úlcera da Perna/induzido quimicamente , Masculino , Pessoa de Meia-Idade , Mucosite/induzido quimicamente , Policitemia Vera/complicações , Policitemia Vera/mortalidade , Prognóstico , Estudos Retrospectivos , Trombose/epidemiologia , Trombose/etiologia
3.
Am J Transplant ; 18(12): 3007-3020, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29734503

RESUMO

Acute graft-versus-host disease (GVHD) after liver transplant (LTx) is a rare complication with a high mortality rate. Recently, monoclonal antibody (mAb) treatment, specifically with anti-interleukin 2 receptor antibodies (IL2RAb) and anti-tumor necrosis factor-α antibodies (TNFAb), has gained increasing interest. However, evidence is mostly limited to case reports and the efficacy remains unclear. Here, we describe 5 patients with LTx-associated GVHD from our center and provide the results of our systematic literature review to evaluate the potential therapeutic benefit of IL2RAb/TNFAb treatment. Of the combined population of 155 patients (5 in our center and 150 through systematic search), 24 were given mAb (15.5%)-4 with TNFAb (2.6%) and 17 with IL2RAb (11%) ("mAb group")-and compared with patients who received other treatments (referred to as "no-mAb group"). Two-sided Fisher exact tests revealed a better survival when comparing treatment with mAb versus no-mAb (11/24 vs 27/131; P = .018), TNFAb versus no-mAb (3/4 vs 27/131; P = .034), and IL2RAb versus no-mAb (8/17 vs 27/131; P = .029). This systematic review suggests a beneficial effect of mAb treatment and a promising role for TNFAb and IL2RAb as a first-line strategy to treat LTx-associated acute GVHD.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Rejeição de Enxerto/mortalidade , Doença Enxerto-Hospedeiro/mortalidade , Subunidade alfa de Receptor de Interleucina-2/antagonistas & inibidores , Transplante de Fígado/mortalidade , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adulto , Idoso , Feminino , Seguimentos , Rejeição de Enxerto/tratamento farmacológico , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto , Doença Enxerto-Hospedeiro/tratamento farmacológico , Doença Enxerto-Hospedeiro/etiologia , Humanos , Transplante de Fígado/efeitos adversos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida
4.
Ann Oncol ; 29(1): 200-208, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29186353

RESUMO

Background: Reported prevalence of driver gene mutations in non-small-cell lung cancer (NSCLC) is highly variable and clinical correlations are emerging. Using NSCLC biomaterial and clinical data from the European Thoracic Oncology Platform Lungscape iBiobank, we explore the epidemiology of mutations and association to clinicopathologic features and patient outcome (relapse-free survival, time-to-relapse, overall survival). Methods: Clinically annotated, resected stage I-III NSCLC FFPE tissue was assessed for gene mutation using a microfluidics-based multiplex PCR platform. Mutant-allele detection sensitivity is >1% for most of the ∼150 (13 genes) mutations covered in the multiplex test. Results: Multiplex testing has been carried out in 2063 (76.2%) of the 2709 Lungscape cases (median follow-up 4.8 years). FFPE samples mostly date from 2005 to 2008, yet recently extracted DNA quality and quantity was generally good. Average DNA yield/case was 2.63 µg; 38 cases (1.4%) failed QC and were excluded from study; 95.1% of included cases allowed the complete panel of mutations to be tested. Most common were KRAS, MET, EGFR and PIK3CA mutations with overall prevalence of 23.0%, 6.8%, 5.4% and 4.9%, respectively. KRAS and EGFR mutations were significantly more frequent in adenocarcinomas: PIK3CA in squamous cell carcinomas. MET mutation prevalence did not differ between histology groups. EGFR mutations were found predominantly in never smokers; KRAS in current/former smokers. For all the above mutations, there was no difference in outcome between mutated and non-mutated cases. Conclusion: Archival FFPE NSCLC material is adequate for multiplex mutation analysis. In this large, predominantly European, clinically annotated stage I-III NSCLC cohort, none of the mutations characterized showed prognostic significance.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/genética , Mutação , Adulto , Idoso , Idoso de 80 Anos ou mais , Quinase do Linfoma Anaplásico/biossíntese , Quinase do Linfoma Anaplásico/genética , Carcinoma Pulmonar de Células não Pequenas/epidemiologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Análise Mutacional de DNA/métodos , Feminino , Humanos , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Multiplex/métodos , Estadiamento de Neoplasias , Prevalência , Intervalo Livre de Progressão , Proteínas Proto-Oncogênicas c-met/biossíntese , Proteínas Proto-Oncogênicas c-met/genética , Fumar/genética , Adulto Jovem
6.
Am J Transplant ; 16(2): 414-25, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26780579

RESUMO

The molecular pathogenesis of posttransplant diffuse large B cell lymphoma (PT-DLBCL) is largely unknown. We have recently shown that Epstein-Barr virus-positive (EBV(+)) and -negative (EBV(-)) PT-DLBCL have distinct gene expression profiles, and the transcriptomic profile of EBV(-) PT-DLBCL is similar to that of DLBCL in immunocompetent individuals (IC-DLBCL). To validate these observations at the genomic level, we performed array-comparative genome hybridization (aCGH) analysis of 21 EBV(+) PT-DLBCL, 6 EBV(-) PT-DLBCL, and 11 control IC-DLBCL, and subsequently combined genomic and transcriptomic data. The analysis showed that EBV(+) and EBV(-) PT-DLBCL have distinct aCGH profiles and shared only one recurrent imbalance. EBV(-) PT-DLBCL, however, displayed at least 10 aberrations recurrent in IC-DLBCL, among which characteristic gain of 3/3q and 18q, and loss of 6q23/TNFAIP3 as well as 9p21/CDKN2A. The most prevalent aberration in EBV(+) PT-DLBCL was gain/amplification of 9p24.1 targeting PDCD1LG2/PDL2. Our data indicate that the FOXP1 oncogene and the tumor suppressor CDKNA2 implicated in EBV(-) DLBCL, do not play a critical role in the pathogenesis of EBV(+) PT-DLBCL. Altogether, genomic profiling of PT-/IC-DLBCL confirms that EBV(-) and EBV(+) PT-DLBCL are distinct entities, while EBV(-) PT-DLBCL has features in common with IC-DLBCL. These findings support the hypothesis that EBV(-) PT-DLBCL are de novo lymphomas in transplant recipients.


Assuntos
Biomarcadores Tumorais/genética , Infecções por Vírus Epstein-Barr/genética , Perfilação da Expressão Gênica , Genômica/métodos , Linfoma Difuso de Grandes Células B/genética , Complicações Pós-Operatórias/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Criança , Pré-Escolar , Hibridização Genômica Comparativa , Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/virologia , Feminino , Seguimentos , Rejeição de Enxerto , Sobrevivência de Enxerto , Herpesvirus Humano 4 , Humanos , Técnicas Imunoenzimáticas , Hibridização In Situ , Linfoma Difuso de Grandes Células B/cirurgia , Linfoma Difuso de Grandes Células B/virologia , Masculino , Pessoa de Meia-Idade , Prognóstico , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Adulto Jovem
7.
Nat Genet ; 27(3): 313-7, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11242115

RESUMO

The Wiskott-Aldrich syndrome protein (WASP; encoded by the gene WAS) and its homologs are important regulators of the actin cytoskeleton, mediating communication between Rho-family GTPases and the actin nucleation/crosslinking factor, the Arp2/3 complex. Many WAS mutations impair cytoskeletal control in hematopoietic tissues, resulting in functional and developmental defects that define the X-linked Wiskott-Aldrich syndrome (WAS) and the related X-linked thrombocytopenia (XLT). These diseases seem to result from reduced WASP signaling, often through decreased transcription or translation of the gene. Here we describe a new disease, X-linked severe congenital neutropenia (XLN), caused by a novel L270P mutation in the region of WAS encoding the conserved GTPase binding domain (GBD). In vitro, the mutant protein is constitutively activated through disruption of an autoinhibitory domain in the wild-type protein, indicating that loss of WASP autoinhibition is a key event in XLN. Our findings highlight the importance of precise regulation of WASP in hematopoietic development and function, as impairment versus enhancement of its activity give rise to distinct spectra of cellular defects and clinical phenotypes.


Assuntos
Ligação Genética , Neutropenia/congênito , Neutropenia/genética , Mutação Puntual , Proteínas/genética , Cromossomo X/genética , Sequência de Bases , DNA/genética , Primers do DNA/genética , Feminino , Humanos , Subpopulações de Linfócitos , Masculino , Modelos Moleculares , Neutropenia/sangue , Linhagem , Conformação Proteica , Proteínas/química , Síndrome de Wiskott-Aldrich/genética , Proteína da Síndrome de Wiskott-Aldrich
8.
Nat Genet ; 36(10): 1084-9, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15361874

RESUMO

In T-cell acute lymphoblastic leukemia (T-ALL), transcription factors are known to be deregulated by chromosomal translocations, but mutations in protein tyrosine kinases have only rarely been identified. Here we describe the extrachromosomal (episomal) amplification of ABL1 in 5 of 90 (5.6%) individuals with T-ALL, an aberration that is not detectable by conventional cytogenetics. Molecular analyses delineated the amplicon as a 500-kb region from chromosome band 9q34, containing the oncogenes ABL1 and NUP214 (refs. 5,6). We identified a previously undescribed mechanism for activation of tyrosine kinases in cancer: the formation of episomes resulting in a fusion between NUP214 and ABL1. We detected the NUP214-ABL1 transcript in five individuals with the ABL1 amplification, in 5 of 85 (5.8%) additional individuals with T-ALL and in 3 of 22 T-ALL cell lines. The constitutively phosphorylated tyrosine kinase NUP214-ABL1 is sensitive to the tyrosine kinase inhibitor imatinib. The recurrent cryptic NUP214-ABL1 rearrangement is associated with increased HOX expression and deletion of CDKN2A, consistent with a multistep pathogenesis of T-ALL. NUP214-ABL1 expression defines a new subgroup of individuals with T-ALL who could benefit from treatment with imatinib.


Assuntos
Genes abl , Leucemia-Linfoma de Células T do Adulto/genética , Complexo de Proteínas Formadoras de Poros Nucleares/genética , Plasmídeos/genética , Sequência de Aminoácidos , Fusão Gênica Artificial , Sequência de Bases , Benzamidas , Linhagem Celular Tumoral , Cromossomos Humanos Par 9/genética , DNA de Neoplasias/genética , Inibidores Enzimáticos/uso terapêutico , Amplificação de Genes , Humanos , Mesilato de Imatinib , Hibridização in Situ Fluorescente , Leucemia-Linfoma de Células T do Adulto/tratamento farmacológico , Leucemia-Linfoma de Células T do Adulto/enzimologia , Dados de Sequência Molecular , Piperazinas/uso terapêutico , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/genética , Pirimidinas/uso terapêutico
9.
J Exp Med ; 175(4): 951-60, 1992 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-1372649

RESUMO

CD28 is an adhesion receptor expressed as a 44-kD dimer on the surface of a major subset of human T cells. The CD28 receptor regulates the production of multiple lymphokines, including interleukin 2 (IL-2), by activation of a signal transduction pathway that is poorly understood. Here we show that ligation of CD28 by a monoclonal antibody (mAb) or by a natural ligand, B7/BB1, induces protein tyrosine phosphorylation that is distinct from T cell receptor (TCR)-induced tyrosine phosphorylation. CD28-induced protein tyrosine phosphorylation was greatly enhanced in cells that had been preactivated by ligation of the TCR, or by pretreatment with phorbol esters. Rapid and prolonged tyrosine phosphorylation of a single substrate, pp100, was induced in T cells after interaction with B7/BB1 presented on transfected Chinese hamster ovary (CHO) cells. Anti-B7 mAb inhibited B7/BB1 receptor-induced tyrosine phosphorylation, indicating that B7-CD28 interaction was required. CD28-induced tyrosine phosphorylation was independent of the TCR because it occurred in a variant of the Jurkat T cell line that does not express the TCR. Herbimycin A, a protein tyrosine kinase inhibitor, could prevent CD28-induced tyrosine phosphorylation and CD28-induced IL-2 production in normal T cells. The simultaneous crosslinking of CD28 and CD45, a tyrosine phosphatase, could prevent tyrosine phosphorylation of pp100. These results suggest that specific tyrosine phosphorylation, particularly of pp100, occurs directly as a result of CD28 ligand binding and is involved in transducing the signal delivered through CD28 by accessory cells that express the B7/BB1 receptor. Thus, this particular form of signal transduction may be relevant to lymphokine production and, potentially may provide a means to study the induction of self-tolerance, given the putative role of the costimulatory signal in the induction of T cell activation or anergy.


Assuntos
Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Receptores de Superfície Celular/metabolismo , Linfócitos T/metabolismo , Anticorpos Monoclonais/imunologia , Antígenos CD/fisiologia , Benzoquinonas , Antígenos CD28 , Antígenos de Histocompatibilidade/fisiologia , Humanos , Técnicas In Vitro , Interleucina-2/farmacologia , Lactamas Macrocíclicas , Antígenos Comuns de Leucócito , Peso Molecular , Fosfoproteínas/metabolismo , Fosforilação , Fosfotirosina , Quinonas/farmacologia , Agregação de Receptores , Rifabutina/análogos & derivados , Transdução de Sinais , Acetato de Tetradecanoilforbol/farmacologia , Fatores de Tempo , Células Tumorais Cultivadas , Tirosina/análogos & derivados , Tirosina/metabolismo
12.
Pediatr Blood Cancer ; 53(2): 220-2, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19405140

RESUMO

We report on an acute myeloid leukemia in a neonate whose mother was exposed to diethylstilboestrol in utero. The newborn presented with leukemia cutis, hemorrhagic skin lesions, hyperleucocytosis and disseminated intravascular coagulation. A bone marrow examination confirmed the diagnosis of acute monocytic leukemia with a t(11;19) MLL-ELL fusion transcript. Chemotherapy was initiated but the child developed a bilateral pulmonary infection that led to fatal respiratory distress. This case shows acute myeloid leukemia and the third pediatric leukemia reported after maternal diethylstilboestrol exposure.


Assuntos
Dietilestilbestrol/efeitos adversos , Estrogênios não Esteroides/efeitos adversos , Leucemia Mieloide Aguda/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Feminino , Humanos , Hibridização in Situ Fluorescente , Recém-Nascido , Infertilidade Feminina/induzido quimicamente , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Masculino , Mães , Proteína de Leucina Linfoide-Mieloide , Proteínas de Fusão Oncogênica , Linhagem , Gravidez , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
Leukemia ; 33(8): 1910-1922, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30858550

RESUMO

Minimal residual disease (MRD) is a powerful prognostic factor in acute lymphoblastic leukemia (ALL) and is used for patient stratification and treatment decisions, but its precise role in Philadelphia chromosome positive ALL is less clear. This uncertainty results largely from methodological differences relating to the use of real-time quantitative PCR (qRT-PCR) to measure BCR-ABL1 transcript levels for MRD analysis. We here describe the first results by the EURO-MRD consortium on standardization of qRT-PCR for the e1a2 BCR-ABL1 transcript in Ph + ALL, designed to overcome the lack of standardisation of laboratory procedures and data interpretation. Standardised use of EAC primer/probe sets and of centrally prepared plasmid standards had the greatest impact on reducing interlaboratory variability. In QC1 the proportion of analyses with BCR-ABL1/ABL1 ratios within half a log difference were 40/67 (60%) and 52/67 (78%) at 10-3 and 36/67 (53%) and 53/67 (79%) at 10-4BCR-ABL1/ABL1. Standardized RNA extraction, cDNA synthesis and cycler platforms did not improve results further, whereas stringent application of technical criteria for assay quality and uniform criteria for data interpretation and reporting were essential. We provide detailed laboratory recommendations for the standardized MRD analysis in routine diagnostic settings and in multicenter clinical trials for Ph + ALL.


Assuntos
Proteínas de Fusão bcr-abl/genética , Cromossomo Filadélfia , Guias de Prática Clínica como Assunto , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Consenso , Humanos , Neoplasia Residual , RNA Mensageiro/análise
14.
Leukemia ; 21(4): 668-77, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17301818

RESUMO

Multilineage dysplasia was advanced by the World Health Organization to increase prognostic accuracy in myelodysplastic syndromes (MDS) classification. We performed a structured cytomorphological examination of bone marrow (BM) in 221 low-grade MDS patients, this in conjunction with strict guidelines for cytopenias. A dysplasia scoring system was developed utilizing dysplastic changes, which were associated with worse outcome on univariate and multivariate analysis corrected for the International Prognostic Scoring System (IPSS). Dysplasia >or=10% in one BM lineage and one cytopenia constituted the low-risk category UCUD or Unilineage Cytopenia and Unilineage Dysplasia. The high-risk category comprised patients with cytopenia in >or=2 lineages and dysplasia in >or=2 BM lineages, namely MCMD or Multilineage Cytopenia and Multilineage Dysplasia. Intermediate-risk patients had one cytopenia and multilineage dysplasia, or cytopenia in >or=2 lineages and unilineage BM dysplasia, designated UCMD/MCUD or Unilineage Cytopenia and Multilineage Dysplasia/Multilineage Cytopenia and Unilineage Dysplasia. This system utilizing cytopenia-dysplasia scoring at diagnosis enabled comprehensive categorization of low-grade MDS cases that predicted for overall as well as leukemia-free survival. Cytopenia-dysplasia categorization added additional prognostic values to the lower risk IPSS categories. This suggests that a standardized dysplasia scoring system, used in conjunction with cytopenia, could improve diagnostic and prognostic sub-categorization of MDS patients.


Assuntos
Megaloblastos/patologia , Síndromes Mielodisplásicas/classificação , Análise de Variância , Medula Óssea/patologia , Células da Medula Óssea/patologia , Cariotipagem , Análise Multivariada , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/mortalidade , Síndromes Mielodisplásicas/patologia , Análise de Sobrevida , Organização Mundial da Saúde
15.
Leukemia ; 21(8): 1715-22, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17541398

RESUMO

Chromosomal translocations represent an important prognostic indicator in B-cell chronic lymphocytic leukemia (B-CLL). However, their value had been neither determined in homogeneously treated patients nor compared to that of IgV(H) mutational status. Sixty-five B-CLL patients were investigated using cytogenetics, interphase fluorescence in situ hybridization (FISH), analysis of IgV(H) and of TP53 mutational status before treatment with 2-chloro-2'-deoxyadenosine (CdA). Translocations (n=45) were detected in 42% of the patients, including both balanced (n=12) and unbalanced (n=33) types. IgV(H) was mutated in 43% of the patients. Patients with translocations were more heavily pretreated (P=0.05), presented with more complex karyotypes (P<0.001), 17p abnormalities and TP53 mutations, and had a higher failure rate (59 vs 21% in patients without translocations, P=0.004). Patients with unbalanced translocations displayed a shorter median treatment-free survival (TFS, 6.9 vs 35.9 months, log rank 22.72, P<0.001) and overall survival (OS, 13.0 vs 68.0 months, log rank 16.51, P<0.001), as compared to patients without translocation. In multivariate analysis, unbalanced translocations were independently associated with therapeutic failure, short TFS and short OS. IgV(H) mutational status was independently associated with risk of failure and TFS, but not OS. In B-CLL patients treated with CdA, translocations are strong predictors of outcome.


Assuntos
Antineoplásicos/uso terapêutico , Cladribina/uso terapêutico , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/mortalidade , Translocação Genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Aberrações Cromossômicas , Cromossomos Humanos Par 11/genética , Cromossomos Humanos Par 13/genética , Cromossomos Humanos Par 17/genética , Feminino , Humanos , Hibridização in Situ Fluorescente , Interfase , Cariotipagem , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Mutação/genética , Prognóstico , Fatores de Risco , Taxa de Sobrevida , Falha de Tratamento , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
16.
Leukemia ; 21(7): 1451-9, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17508005

RESUMO

We studied the effect of CTLA-4 blockade on graft-versus-leukemia and graft-versus-host responses in a mouse model of minor histocompatibility-mismatched bone marrow transplantation. Early CTLA-4 blockade induced acute graft-versus-host disease. Delayed CTLA-4 blockade resulted in a lethal condition with lymphosplenomegaly, but with stable mixed T-cell chimerism, unchanged alloreactive T-cell frequencies and absent anti-host reactivity in vitro. In contrast, multiorgan lymphoproliferative disease with autoimmune hepatitis and circulating anti-DNA auto-antibodies were documented. Splenic lymphocytes exhibited ex vivo spontaneous proliferation and a marked proliferative response against host-type dendritic cells pulsed with syngeneic (host-type) tissue-peptides. Both phenomena were exclusively mediated by host and not donor T cells, supporting an autoimmune pathogenesis. Selectively host-derived T-cell immune reactivity was equally documented against leukemia-peptide-pulsed dendritic cells, and this was paralleled by a strong in vivo antileukemic effect in anti-CTLA-4-treated and subsequently leukemia-challenged chimeras. In conclusion, delayed CTLA-4 blockade induced a host-derived antileukemic effect, occurring in the context of an autoimmune syndrome and strictly separated from graft-versus-host disease. Both antileukemic and autoimmune responses depended on the allogeneic component, as neither effect was seen after syngeneic bone marrow transplantation. Our findings reveal the potential of using CTLA-4 blockade to establish antileukemic effects after allogeneic hematopoietic stem cell transplantation, provided autoimmunity can be controlled.


Assuntos
Antígenos CD/efeitos dos fármacos , Antígenos de Diferenciação/efeitos dos fármacos , Transplante de Medula Óssea , Efeito Enxerto vs Leucemia , Quimeras de Transplante , Animais , Antígenos CD/imunologia , Antígenos de Diferenciação/imunologia , Autoimunidade , Antígeno CTLA-4 , Doença Enxerto-Hospedeiro , Histocompatibilidade , Leucemia/terapia , Camundongos , Linfócitos T/imunologia , Resultado do Tratamento
17.
Leukemia ; 21(3): 397-402, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17215855

RESUMO

We investigated genetically affected leukemic cells in FIP1L1-PDGFRA+ chronic eosinophilic leukemia (CEL) and in BCR-ABL1+ chronic myeloid leukemia (CML), two myeloproliferative disorders responsive to imatinib. Fluorescence in situ hybridization specific for BCR-ABL1 and for FIP1L1-PDGFRA was combined with cytomorphology or with lineage-restricted monoclonal antibodies and applied in CML and CEL, respectively. In CEL the amount of FIP1L1-PDGFRA+ cells among CD34+ and CD133+ cells, B and T lymphocytes, and megakaryocytes were within normal ranges. Positivity was found in eosinophils, granulo-monocytes and varying percentages of erythrocytes. In vitro assays with imatinib showed reduced survival of peripheral blood mononuclear cells but no reduction in colony-forming unit growth medium (CFU-GM) growth. In CML the BCR-ABL1 fusion gene was detected in CD34+/CD133+ cells, granulo-monocytes, eosinophils, erythrocytes, megakaryocytes and B-lymphocytes. Growth of both peripheral blood mononuclear cells and CFU-GM was inhibited by imatinib. This study provided evidence for marked differences in the leukemic masses which are targeted by imatinib in CEL or CML, as harboring FIP1L1-PDGFRA or BCR-ABL1.


Assuntos
Proteínas de Fusão bcr-abl/análise , Síndrome Hipereosinofílica/patologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Células-Tronco Neoplásicas/enzimologia , Proteínas de Fusão Oncogênica/análise , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/análise , Fatores de Poliadenilação e Clivagem de mRNA/análise , Antígeno AC133 , Antígenos CD/análise , Antígenos CD34/análise , Antineoplásicos/uso terapêutico , Benzamidas , Linhagem da Célula , Doença Crônica , Células Clonais/enzimologia , Resistência a Medicamentos , Eosinófilos/enzimologia , Eritrócitos/enzimologia , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Glicoforinas/análise , Glicoproteínas/análise , Granulócitos/enzimologia , Células-Tronco Hematopoéticas/enzimologia , Humanos , Síndrome Hipereosinofílica/tratamento farmacológico , Síndrome Hipereosinofílica/enzimologia , Síndrome Hipereosinofílica/genética , Mesilato de Imatinib , Imunofenotipagem , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/enzimologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Subpopulações de Linfócitos/enzimologia , Megacariócitos/enzimologia , Monócitos/enzimologia , Células Mieloides/enzimologia , Proteínas de Fusão Oncogênica/antagonistas & inibidores , Peptídeos/análise , Piperazinas/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Ensaio Tumoral de Célula-Tronco , Inativação do Cromossomo X , Fatores de Poliadenilação e Clivagem de mRNA/antagonistas & inibidores
18.
Hematology ; 23(10): 785-792, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29993347

RESUMO

OBJECTIVES: CML, PV, ET and PMF are so called classical MPN with distinct clinical phenotypes. The discovery of the BCR-ABL1 translocation and mutations in driver genes JAK2, MPL and CALR has provided novel insights in their pathogenesis. While these mutations are thought to be mutually exclusive, rare cases of MPN with coexisting driver mutations have been reported. However, little is known about the clinical, biological and molecular characteristics of these patients and the interaction of the neoplastic clones. METHODS: We retrospectively studied 11 MPN patients with coexisting driver mutations (JAK2 V617F + BCR-ABL1: n = 8; CALR type 2 + BCR-ABL1: n = 1; JAK2 V617F + MPL W515: n = 1; JAK2 V617F + CALR type 1: n = 1). To assess possible associated molecular aberrations, we analysed DNA of six patients using NGS. RESULTS: In four CML patients, decreasing BCR-ABL1 transcript levels with increasing JAK2 V617F allele burden under TKI were observed. This strongly suggests that the coexistence of driver mutations originates from two different clones growing independently. Additional somatic mutations were detected in 5 out of 6 (83%) patients affecting 4 different genes, confirming the heterogeneity of this study cohort. Suboptimal response to TKI was observed with a higher frequency (4/8 patients) than reported in conventional series of CML and the overall tolerance of treatment with hydroxyurea and/or imatinib in our series was poor. CONCLUSION: Given the emergence of NGS in clinical practice, more similar cases will be identified in the coming years. The optimal treatment strategy for this rare group of patients is uncertain and toxicity of combination treatment may have to be considered.


Assuntos
Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Hematológicas/genética , Mutação , Transtornos Mieloproliferativos/genética , Proteínas de Neoplasias/genética , Adulto , Idoso , Feminino , Neoplasias Hematológicas/tratamento farmacológico , Humanos , Hidroxiureia , Masculino , Pessoa de Meia-Idade , Transtornos Mieloproliferativos/tratamento farmacológico
19.
Leukemia ; 20(9): 1496-510, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16826225

RESUMO

For long, T-cell acute lymphoblastic leukemia (T-ALL) remained in the shadow of precursor B-ALL because it was more seldom, and showed a normal karyotype in more than 50% of cases. The last decennia, intense research has been carried out on different fronts. On one side, development of normal thymocyte and its regulation mechanisms have been studied in multiple mouse models and subsequently validated. On the other side, molecular cytogenetics (fluorescence in situ hybridization) and mutation analysis revealed cytogenetically cryptic aberrations in almost all cases of T-ALL. Also, expression microarray analysis disclosed gene expression signatures that recapitulate specific stages of thymocyte development. Investigations are still very much actual, fed by the discovery of new genetic aberrations. In this review, we present a summary of the current cytogenetic changes associated with T-ALL. The genes deregulated by translocations or mutations appear to encode proteins that are also implicated in T-cell development, which prompted us to review the 'normal' and 'leukemogenic' functions of these transcription regulators. To conclude, we show that the paradigm of multistep leukemogenesis is very much applicable to T-ALL and that the different genetic insults collaborate to maintain self-renewal capacity, and induce proliferation and differentiation arrest of T-lymphoblasts. They also open perspectives for targeted therapies.


Assuntos
Leucemia-Linfoma de Células T do Adulto/genética , Linfócitos/patologia , Timo/patologia , Linhagem da Célula , Aberrações Cromossômicas , Genes Homeobox , Humanos , Leucemia-Linfoma de Células T do Adulto/enzimologia , Leucemia-Linfoma de Células T do Adulto/patologia , Proteínas Tirosina Quinases/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Transdução de Sinais
20.
Verh K Acad Geneeskd Belg ; 69(5-6): 291-313, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18351210

RESUMO

Cancer in a patient usually becomes manifest as a process of excessive cell growth in one or more organs which, if uncontrolled, will ultimately lead to death of the patient. The malignant clinical phenotype of cancer is the reflection of the altered cellular behaviour of individual cancer cells. Cumulative genetic alterations in pathways controlling cellular growth or survival, endow the latter cells with the capacity to grow independently of growth-regulating signals, to resist programmed cell death, to divide endlessly, and to interact differently with non-malignant cellular environment. The discovery of such recurrent genetic aberrations in haematological malignancies has led to new diagnostic tests, but also to a shift towards development of new rational, specific and effective targets for therapy. For instance, protein tyrosine kinases are pivotal switches for growth control, and small molecule inhibitors have profoundly reshaped therapeutic practice in in myeloproliferative disorders or acute lymphoblastic leukemias. New targets however also encompass the detrimental interactions of malignant cells with the normal environment, e.g. the immune system in the myelodysplastic syndromes. Finally, the paradigm of cancer as the result of cumulative genetic damage in normal cells also sheds new light on the vulnerability of congenital bone marrow failure syndromes to develop haematological malignancies. In this paper, we review our recent contributions to this cancer paradigm in malignant or premalignant haematological conditions.


Assuntos
Neoplasias Hematológicas/genética , Modelos Genéticos , Oncogenes/genética , Aberrações Cromossômicas , Humanos , Biologia Molecular
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA