RESUMO
BACKGROUND: Somatic mutations in the Janus kinase 2 gene (JAK2) occur in many myeloproliferative neoplasms, but the molecular pathogenesis of myeloproliferative neoplasms with nonmutated JAK2 is obscure, and the diagnosis of these neoplasms remains a challenge. METHODS: We performed exome sequencing of samples obtained from 151 patients with myeloproliferative neoplasms. The mutation status of the gene encoding calreticulin (CALR) was assessed in an additional 1345 hematologic cancers, 1517 other cancers, and 550 controls. We established phylogenetic trees using hematopoietic colonies. We assessed calreticulin subcellular localization using immunofluorescence and flow cytometry. RESULTS: Exome sequencing identified 1498 mutations in 151 patients, with medians of 6.5, 6.5, and 13.0 mutations per patient in samples of polycythemia vera, essential thrombocythemia, and myelofibrosis, respectively. Somatic CALR mutations were found in 70 to 84% of samples of myeloproliferative neoplasms with nonmutated JAK2, in 8% of myelodysplasia samples, in occasional samples of other myeloid cancers, and in none of the other cancers. A total of 148 CALR mutations were identified with 19 distinct variants. Mutations were located in exon 9 and generated a +1 base-pair frameshift, which would result in a mutant protein with a novel C-terminal. Mutant calreticulin was observed in the endoplasmic reticulum without increased cell-surface or Golgi accumulation. Patients with myeloproliferative neoplasms carrying CALR mutations presented with higher platelet counts and lower hemoglobin levels than patients with mutated JAK2. Mutation of CALR was detected in hematopoietic stem and progenitor cells. Clonal analyses showed CALR mutations in the earliest phylogenetic node, a finding consistent with its role as an initiating mutation in some patients. CONCLUSIONS: Somatic mutations in the endoplasmic reticulum chaperone CALR were found in a majority of patients with myeloproliferative neoplasms with nonmutated JAK2. (Funded by the Kay Kendall Leukaemia Fund and others.).
Assuntos
Calreticulina/genética , Mutação , Síndromes Mielodisplásicas/genética , Mielofibrose Primária/genética , Trombocitemia Essencial/genética , Sequência de Aminoácidos , Doenças da Medula Óssea/genética , Calreticulina/análise , Éxons , Humanos , Janus Quinase 2/genética , Leucemia Mieloide/genética , Dados de Sequência Molecular , Neoplasias/genética , Reação em Cadeia da Polimerase , Análise de Sequência de DNARESUMO
BACKGROUND: Myelodysplastic syndromes are a diverse and common group of chronic hematologic cancers. The identification of new genetic lesions could facilitate new diagnostic and therapeutic strategies. METHODS: We used massively parallel sequencing technology to identify somatically acquired point mutations across all protein-coding exons in the genome in 9 patients with low-grade myelodysplasia. Targeted resequencing of the gene encoding RNA splicing factor 3B, subunit 1 (SF3B1), was also performed in a cohort of 2087 patients with myeloid or other cancers. RESULTS: We identified 64 point mutations in the 9 patients. Recurrent somatically acquired mutations were identified in SF3B1. Follow-up revealed SF3B1 mutations in 72 of 354 patients (20%) with myelodysplastic syndromes, with particularly high frequency among patients whose disease was characterized by ring sideroblasts (53 of 82 [65%]). The gene was also mutated in 1 to 5% of patients with a variety of other tumor types. The observed mutations were less deleterious than was expected on the basis of chance, suggesting that the mutated protein retains structural integrity with altered function. SF3B1 mutations were associated with down-regulation of key gene networks, including core mitochondrial pathways. Clinically, patients with SF3B1 mutations had fewer cytopenias and longer event-free survival than patients without SF3B1 mutations. CONCLUSIONS: Mutations in SF3B1 implicate abnormalities of messenger RNA splicing in the pathogenesis of myelodysplastic syndromes. (Funded by the Wellcome Trust and others.).
Assuntos
Síndromes Mielodisplásicas/genética , Fosfoproteínas/genética , Mutação Puntual , Ribonucleoproteína Nuclear Pequena U2/genética , Eritrócitos/patologia , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Fenótipo , Fatores de Processamento de RNARESUMO
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 & inibidoresRESUMO
The FIP1L1-PDGFRA fusion gene has been described in patients with eosinophilia-associated myeloproliferative disorders (Eos-MPD). Here, we report on seven FIP1L1-PDGFRA-positive patients who presented with acute myeloid leukemia (AML, n=5) or lymphoblastic T-cell non-Hodgkin-lymphoma (n=2) in conjunction with AML or Eos-MPD. All patients were male, the median age was 58 years (range, 40-66). AML patients were negative for common mutations of FLT3, NRAS, NPM1, KIT, MLL and JAK2; one patient revealed a splice mutation of RUNX1 exon 7. Patients were treated with imatinib (100 mg, n=5; 400 mg, n=2) either as monotherapy (n=2), as maintenance treatment after intensive chemotherapy (n=3) or in overt relapse 43 and 72 months, respectively, after primary diagnosis and treatment of FIP1L1-PDGFRA-positive disease (n=2). All patients are alive, disease-free and in complete hematologic and complete molecular remission after a median time of 20 months (range, 9-36) on imatinib. The median time to achievement of complete molecular remission was 6 months (range, 1-14). We conclude that all eosinophilia-associated hematological malignancies should be screened for the presence of the FIP1L1-PDGFRA fusion gene as they are excellent candidates for treatment with tyrosine kinase inhibitors even if they present with an aggressive phenotype such as AML.
Assuntos
Eosinofilia/tratamento farmacológico , Leucemia Mieloide/tratamento farmacológico , Proteínas de Fusão Oncogênica/análise , Piperazinas/administração & dosagem , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Pirimidinas/administração & dosagem , Receptor alfa de Fator de Crescimento Derivado de Plaquetas , Fatores de Poliadenilação e Clivagem de mRNA , Doença Aguda , Adulto , Idoso , Benzamidas , Intervalo Livre de Doença , Eosinofilia/complicações , Humanos , Mesilato de Imatinib , Masculino , Pessoa de Meia-Idade , Transtornos Mieloproliferativos/tratamento farmacológico , Nucleofosmina , Proteínas de Fusão Oncogênica/genética , Proteínas Tirosina Quinases/antagonistas & inibidores , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Indução de Remissão/métodos , Fatores de Poliadenilação e Clivagem de mRNA/genéticaRESUMO
Idiopathic hypereosinophilic syndrome (IHES) is a disease that is difficult to classify, and diagnosis is one of exclusion. The identification of a cytogenetically invisible interstitial deletion resulting in the fusion of FIP1-Like-1 (FIP1L1) to platelet-derived growth factor receptor alpha (PDGFRA) has enabled many IHES cases to be reclassified as chronic eosinophilic leukemia. As it is likely that PDGFRA may fuse to other partner genes, we established a reverse transcriptase-PCR test to detect specific overexpression of the PDGFRA kinase domain as an indicator of the presence of a fusion gene. Overexpression was detected in 12/12 FIP1L1-PDGFRA-positive patients, plus 9/217 (4%) patients with hypereosinophilia who had tested negative for FIP1L1-PDGFRA. One of the positive cases was investigated in detail and found to have a complex karyotype involving chromosomes 3, 4 and 10. Amplification of the genomic breakpoint by bubble PCR revealed a novel fusion between KIF5B at 10p11 and PDGFRA at 4q12. Imatinib, a known inhibitor of PDGFRalpha, produced a complete cytogenetic response and disappearance of the KIF5B-PDGFRA fusion by PCR, from both genomic DNA and mRNA. This study demonstrates the utility of screening for PDGFRA kinase domain overexpression in patients with IHES and has identified a third PDGFRA fusion partner in chronic myeloproliferative disorders.
Assuntos
Antineoplásicos/farmacologia , Regulação Neoplásica da Expressão Gênica , Testes Genéticos , Síndrome Hipereosinofílica/genética , Fusão Oncogênica/genética , Piperazinas/farmacologia , Proteínas Tirosina Quinases/genética , Pirimidinas/farmacologia , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Antineoplásicos/uso terapêutico , Benzamidas , Estudos de Coortes , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Rearranjo Gênico , Humanos , Síndrome Hipereosinofílica/tratamento farmacológico , Mesilato de Imatinib , Hibridização in Situ Fluorescente , Masculino , Pessoa de Meia-Idade , Piperazinas/uso terapêutico , Proteínas Tirosina Quinases/efeitos dos fármacos , Pirimidinas/uso terapêutico , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/genética , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Indução de Remissão , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Sensibilidade e Especificidade , Resultado do TratamentoRESUMO
Molecular monitoring for patients with chronic myeloid leukaemia (CML) has become an important practice in the era of imatinib therapy. For successful widespread introduction into the mainstream patient monitoring schedule, many procedural aspects of the complex real-time quantitative polymerase chain reaction (RQ-PCR) technique for measuring BCR-ABL transcripts require optimization. Recommendations for harmonizing the differing methodologies have recently been proposed. These recommendations were designed to maximize reliability of analysis for clinical decision making and proposed the adoption of an International Scale of measurement. The purpose of this review is to present the evidence and supporting data for specific recommendations. These recommendations include use of the same source of cells, either blood or marrow, for analysis; for validation of equal PCR amplification efficiencies of cDNA and standards when using a plasmid to construct standard curves and for ensuring ongoing high-level performance by undertaking a quality assurance programme. Clinicians must know the measurement reliability of an RQ-PCR assay to be able to determine the significance of a change in BCR-ABL level. An assay with poor precision limits the clinical usefulness of results. International harmonization should establish RQ-PCR measurement of BCR-ABL as the best method for monitoring treatment response for patients with CML.
Assuntos
Monitoramento de Medicamentos/métodos , Proteínas de Fusão bcr-abl/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Reação em Cadeia da Polimerase/métodos , Humanos , Reação em Cadeia da Polimerase/normas , Controle de Qualidade , RNA Mensageiro/análise , Reprodutibilidade dos TestesRESUMO
In myeloma, the prognostic impact of different strategies used to detect chromosome 13 deletion (Delta13) remains controversial. To address this, we compared conventional cytogenetics and interphase fluorescence in situ hybridization (iFISH) in a large multicenter study (n=794). The ability to obtain abnormal metaphases was associated with a poor prognosis, which was worse if Delta13, p53 deletion or t(4;14) was present, but only Delta13 remained significant on multivariate analysis. Patients with Delta13, by either cytogenetics or iFISH, had a poor prognosis. However, when cases with Delta13 detectable by both cytogenetics and iFISH were separated from those detected by iFISH only, the poor prognosis of iFISH-detectable Delta13 disappeared; their outcome matched that of patients with no detectable Delta13 (P=0.115). Addition of ploidy status to iFISH-Delta13 did not affect the prognostic value of the test. Indeed both cytogenetics and iFISH Delta13 divided both hyperdiploidy and nonhyperdiploidy into two groups with similar prognoses, indicating that the poor prognosis of ploidy is entirely due to its association with Delta13. We conclude that Delta13 detected by metaphase analysis is a critical prognostic factor in myeloma. Absence of Delta13, even in those patients yielding only normal or no metaphases, is associated with a relatively good prognosis.
Assuntos
Deleção Cromossômica , Cromossomos Humanos Par 13 , Mieloma Múltiplo/genética , Mieloma Múltiplo/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Genes de Cadeia Pesada de Imunoglobulina , Genes p53 , Humanos , Hibridização in Situ Fluorescente , Masculino , Pessoa de Meia-Idade , Ploidias , Prognóstico , Análise de Sobrevida , Translocação GenéticaRESUMO
Mutations in the epigenetic regulator gene EZH2 are frequently observed in patients with myelodysplastic/myeloproliferative neoplasms (MDS/MPN; 10-13%) and are associated with a poor outcome. To gain more insight into EZH2 pathology, we sought to genetically characterize a cohort of 41 EZH2-mutated MDS/MPN patients using targeted deep next-generation sequencing (NGS), colony-forming progenitor assays and transcriptome analysis. Stable short hairpin RNA (shRNA)-mediated downregulation of EZH2 was performed in MDS-derived F-36P, MOLM-13 and OCI-M2 cells to study EZH2-specific changes. Targeted NGS revealed a complex pattern of mutations with a total of 190 individual mutations. EZH2 mutations frequently co-occur with TET2 (58%), RUNX1 (40%) and ASXL1 (34%) mutations. Colony assays indicated EZH2 mutations to be mostly early events in leukemogenesis and showed a complex mutational hierarchy. Gene expression data revealed a number of differently expressed genes between EZH2 wild-type and mutant patients including known EZH2 targets. Comparison of patient transcriptome to EZH2-downregulated cell line data revealed several genes as novel EZH2 targets, showing opposite as well as unidirectional regulation between cell lines and patients. Some genes, such as CXXC5, ETS1 and VAV3 have previously been implied to have a role in leukemogenesis. Their precise role in MDS/MPN needs to be further investigated.
Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/genética , Leucemia/genética , Mutação , Carcinogênese/genética , Linhagem Celular , Análise Mutacional de DNA , Regulação Leucêmica da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , HumanosRESUMO
Before the 1990s, lack of evidence for a reactive cause of hypereosinophilia or chronic eosinophilic leukemia (e.g. presence of a clonal cytogenetic abnormality or increased blood or bone marrow blasts) resulted in diagnosticians characterizing such nebulous cases as 'idiopathic hypereosinophilic syndrome (HES)'. However, over the last decade, significant advances in our understanding of the molecular pathophysiology of eosinophilic disorders have shifted an increasing proportion of cases from this idiopathic HES 'pool' to genetically defined eosinophilic diseases with recurrent molecular abnormalities. The majority of these genetic lesions result in constitutively activated fusion tyrosine kinases, the phenotypic consequence of which is an eosinophilia-associated myeloid disorder. Most notable among these is the recent discovery of the cryptic FIP1L1-PDGFRA gene fusion in karyotypically normal patients with systemic mast cell disease with eosinophilia or idiopathic HES, redefining these diseases as clonal eosinophilias. Rearrangements involving PDGFRA and PDGFRB in eosinophilic chronic myeloproliferative disorders, and of fibroblast growth factor receptor 1 (FGFR1) in the 8p11 stem cell myeloproliferative syndrome constitute additional examples of specific genetic alterations linked to clonal eosinophilia. The identification of populations of aberrant T-lymphocytes secreting eosinophilopoietic cytokines such as interleukin-5 establish a pathophysiologic basis for cases of lymphocyte-mediated hypereosinophilia. This recent revival in understanding the biologic basis of eosinophilic disorders has permitted more genetic specificity in the classification of these diseases, and has translated into successful therapeutic approaches with targeted agents such as imatinib mesylate and recombinant anti-IL-5 antibody.
Assuntos
Eosinofilia , Células Clonais , Eosinofilia/classificação , Eosinofilia/genética , Eosinofilia/terapia , Fusão Gênica , Rearranjo Gênico , Humanos , Síndrome Hipereosinofílica/classificação , Síndrome Hipereosinofílica/genética , Síndrome Hipereosinofílica/terapiaRESUMO
The 8p11 myeloproliferative syndrome (EMS) also known as stem cell leukemia-lymphoma syndrome (SCLL) is associated with translocations that disrupt FGFR1. The resultant fusion proteins are constitutively active tyrosine kinases, and different FGFR1 fusions are associated with subtly different disease phenotypes. We report here a patient with a t(8;17)(p11;q23) and an unusual myelodysplastic/myeloproliferative disease (MDS/MPD) characterized by thrombocytopenia due to markedly reduced size and numbers of megakaryocytes, with elevated numbers of monocytes, eosinophils and basophils. A novel mRNA fusion between exon 32 of the myosin XVIIIA gene (MYO18A) at chromosome band 17q11 and exon 9 of FGFR1 was identified. Partial characterization of the genomic breakpoints in combination of bubble-PCR with fluorescence in situ hybridization revealed that the t(8;17) arose from a three-way translocation with breaks at 8p11, 17q11 and 17q23. MYO18A-FGFR1 is structurally similar to other fusion tyrosine kinases and is likely to be the causative transforming lesion in this unusual MDS/MPD.
Assuntos
Cromossomos Humanos Par 17 , Cromossomos Humanos Par 8 , Transtornos Mieloproliferativos/genética , Miosinas/genética , Receptores Proteína Tirosina Quinases/genética , Receptores de Fatores de Crescimento de Fibroblastos/genética , Translocação Genética , Idoso , Sequência de Aminoácidos , Sequência de Bases , Basófilos/patologia , Eosinófilos/patologia , Feminino , Humanos , Megacariócitos/patologia , Dados de Sequência Molecular , Monócitos/patologia , Transtornos Mieloproliferativos/patologia , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos , Trombocitopenia/genética , Trombocitopenia/patologiaRESUMO
Chromosomal translocations that target HMGA2 at chromosome band 12q14 are seen in a variety of malignancies, notably lipoma, pleomorphic salivary adenoma and uterine leiomyoma. Although some HMGA2 fusion genes have been reported, several lines of evidence suggest that the critical pathogenic event is the expression of truncated HMGA2 isoforms. We report here the involvement of HMGA2 in six patients with myeloid neoplasia, dysplastic features and translocations or an inversion involving chromosome bands 12q13-15 and either 7p12, 8q22, 11q23, 12p11, 14q31 or 20q11. Breaks within or very close to HMGA2 were found in all six cases by molecular cytogenetic analysis, leading to overexpression of this gene as assessed by RT-PCR. Truncated transcripts consisting of HMGA2 exons 1-2 or exons 1-3 spliced to intron-derived sequences were identified in two patients, but were not seen in controls. These findings suggest that abnormalities of HMGA2 play an important and previously unsuspected role in myelodysplasia.
Assuntos
Proteína HMGA2/genética , Síndromes Mielodisplásicas/genética , Neoplasias/genética , Translocação Genética , Adenoma/genética , Sequência de Bases , Bandeamento Cromossômico , Mapeamento Cromossômico , Cromossomos Humanos Par 11 , Cromossomos Humanos Par 12 , Cromossomos Humanos Par 7 , Primers do DNA , DNA Complementar/genética , Éxons , Rearranjo Gênico , Humanos , Lipoma/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias das Glândulas Salivares/genética , Transcrição GênicaRESUMO
A simple high throughput micro-fluorescence in situ hybridisation technique (FISH) was used to detect chromosome 13 deletions (delta13), immunoglobulin heavy chain (IgH) rearrangements, t(11;14)(q13;q32), t(4;14)(p16;q32), t(14;16)(q23;q32), p53 loss, and numerical changes of chromosomes 3, 6, 7, 9, 10, 11 and 17 in 228 cases of multiple myeloma (MM), including 33 asymptomatic/smouldering MM (SMM). The patients were not part of a clinical trial and were from 30 different hospitals. In all, 98.4% of cases were abnormal, with 43% having IgH rearrangements and 42% Delta13. The low incidence of IgH rearrangements was due to a decrease in this finding with age (P = 0.001) and the relatively high proportion of elderly patients in our study population (41% >70 years old). The incidence of specific IgH translocations was t(4;14) 11%, t(11;14) 16% and t(14;16) 3%. Univariate statistical testing showed delta13 (P = 0.002), and t(14;16) (P = 0.005) to be associated with shorter survival. This effect was exaggerated for patient's aged 70 years or under but no effect on survival was seen for those over 70 years. In younger patients t(4;14) (P = 0.044) and p53 deletion (P < 0.001) were also significant poor prognostic indicators. Multivariate analysis showed delta13 and t(14;16) to be independent prognostic variables when considered with age and clinical parameters.
Assuntos
Aberrações Cromossômicas , Mieloma Múltiplo/genética , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Seguimentos , Humanos , Hibridização in Situ Fluorescente/métodos , Pessoa de Meia-Idade , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/patologia , Estudos Retrospectivos , Análise de SobrevidaRESUMO
We evaluated the impact of clinical and molecular characteristics on overall survival (OS) in 108 patients with indolent (n=41) and advanced systemic mastocytosis (SM) (advSM, n=67). Organomegaly was measured by magnetic resonance imaging-based volumetry of the liver and spleen. In multivariate analysis of all patients, an increased spleen volume ⩾450 ml (hazard ratio (HR), 5.2; 95% confidence interval (CI), (2.1-13.0); P=0.003) and an elevated alkaline phosphatase (AP; HR 5.0 (1.1-22.2); P=0.02) were associated with adverse OS. The 3-year OS was 100, 77, and 39%, respectively (P<0.0001), for patients with 0 (low risk, n=37), 1 (intermediate risk, n=32) or 2 (high risk, n=39) parameters. For advSM patients with fully available clinical and molecular data (n=60), univariate analysis identified splenomegaly ⩾1200 ml, elevated AP and mutations in the SRSF2/ASXL1/RUNX1 (S/A/R) gene panel as significant prognostic markers. In multivariate analysis, mutations in S/A/R (HR 3.2 (1.1-9.6); P=0.01) and elevated AP (HR 2.6 (1.0-7.1); P=0.03) remained predictive adverse prognostic markers for OS. The 3-year OS was 76 and 38%, respectively (P=0.0003), for patients with 0-1 (intermediate risk, n=28) or 2 (high risk, n=32) parameters. We conclude that splenomegaly, elevated AP and mutations in the S/A/R gene panel are independent of the World Health Organization classification and provide the most relevant prognostic information in SM patients.
Assuntos
Fosfatase Alcalina/sangue , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Mastocitose Sistêmica/diagnóstico , Mutação , Proteínas Repressoras/genética , Fatores de Processamento de Serina-Arginina/genética , Esplenomegalia/patologia , Adulto , Idoso , Feminino , Humanos , Masculino , Mastocitose Sistêmica/genética , Mastocitose Sistêmica/mortalidade , Mastocitose Sistêmica/patologia , Pessoa de Meia-Idade , Prognóstico , Esplenomegalia/diagnóstico por imagem , Taxa de SobrevidaRESUMO
Most patients with KIT D816V(+) advanced systemic mastocytosis (SM) are characterized by somatic mutations in additional genes. We sought to clarify the prognostic impact of such mutations. Genotype and clinical characteristics of 70 multi-mutated KIT D816V(+) advanced SM patients were included in univariate and multivariate analyses. The most frequently identified mutated genes were TET2 (n=33 of 70 patients), SRSF2 (n=30), ASXL1 (n=20), RUNX1 (n=16) and JAK2 (n=11). In univariate analysis, overall survival (OS) was adversely influenced by mutations in SRSF2 (P<0.0001), ASXL1 (P=0.002) and RUNX1 (P=0.03), but was not influenced by mutations in TET2 or JAK2. In multivariate analysis, SRSF2 and ASXL1 remained the most predictive adverse indicators concerning OS. Furthermore, we found that inferior OS and adverse clinical characteristics were significantly influenced by the number of mutated genes in the SRSF2/ASXL1/RUNX1 (S/A/R) panel (P<0.0001). In conclusion, the presence and number of mutated genes within the S/A/R panel are adversely associated with advanced disease and poor survival in KIT D816V(+) SM. On the basis of these findings, inclusion of molecular markers should be considered in upcoming prognostic scoring systems for patients with SM.
Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/genética , Mastocitose Sistêmica/genética , Mutação , Proteínas Nucleares/genética , Proteínas Proto-Oncogênicas c-kit/genética , Proteínas Repressoras/genética , Ribonucleoproteínas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Mastocitose Sistêmica/sangue , Mastocitose Sistêmica/mortalidade , Pessoa de Meia-Idade , Risco , Fatores de Processamento de Serina-ArgininaRESUMO
The Evaluating Nilotinib Efficacy and Safety in Clinical Trials as First-Line Treatment (ENEST1st) study included 1089 patients with newly diagnosed chronic myeloid leukemia in chronic phase. The rate of deep molecular response (MR(4) (BCR-ABL1⩽0.01% on the International Scale or undetectable BCR-ABL1 with ⩾10,000 ABL1 transcripts)) at 18 months was evaluated as the primary end point, with molecular responses monitored by the European Treatment and Outcome Study network of standardized laboratories. This analysis was conducted after all patients had completed 24 months of study treatment (80.9% of patients) or discontinued early. In patients with typical BCR-ABL1 transcripts and ⩽3 months of prior imatinib therapy, 38.4% (404/1052) achieved MR(4) at 18 months. Six patients (0.6%) developed accelerated or blastic phase, and 13 (1.2%) died. The safety profile of nilotinib was consistent with that of previous studies, although the frequencies of some nilotinib-associated adverse events were lower (for example, rash, 21.4%). Ischemic cardiovascular events occurred in 6.0% of patients. Routine monitoring of lipid and glucose levels was not mandated in the protocol. These results support the use of frontline nilotinib, particularly when achievement of a deep molecular response (a prerequisite for attempting treatment-free remission in clinical trials) is a treatment goal.
Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Tirosina Quinases/antagonistas & inibidores , Pirimidinas/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Proteínas de Fusão bcr-abl/genética , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/mortalidade , Masculino , Pessoa de Meia-Idade , Pirimidinas/efeitos adversosRESUMO
Molecular monitoring of chronic myeloid leukemia patients using robust BCR-ABL1 tests standardized to the International Scale (IS) is key to proper disease management, especially when treatment cessation is considered. Most laboratories currently use a time-consuming sample exchange process with reference laboratories for IS calibration. A World Health Organization (WHO) BCR-ABL1 reference panel was developed (MR(1)-MR(4)), but access to the material is limited. In this study, we describe the development of the first cell-based secondary reference panel that is traceable to and faithfully replicates the WHO panel, with an additional MR(4.5) level. The secondary panel was calibrated to IS using digital PCR with ABL1, BCR and GUSB as reference genes and evaluated by 44 laboratories worldwide. Interestingly, we found that >40% of BCR-ABL1 assays showed signs of inadequate optimization such as poor linearity and suboptimal PCR efficiency. Nonetheless, when optimized sample inputs were used, >60% demonstrated satisfactory IS accuracy, precision and/or MR(4.5) sensitivity, and 58% obtained IS conversion factors from the secondary reference concordant with their current values. Correlation analysis indicated no significant alterations in %BCR-ABL1 results caused by different assay configurations. More assays achieved good precision and/or sensitivity than IS accuracy, indicating the need for better IS calibration mechanisms.
Assuntos
Proteínas de Fusão bcr-abl/análise , Calibragem , Proteínas de Fusão bcr-abl/normas , Genes abl , Humanos , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas c-bcr/genética , Padrões de Referência , Organização Mundial da SaúdeRESUMO
Imatinib has shown to be effective against malignant disease driven by ckit. We prospectively treated 12 adults with symptomatic systemic mast-cell disease at a dose of either 100 mg or 400 mg per day. Of the ten patients who we could assess for response, five (50%) had a measurable response to the drug, four of whom had important mast-cell cytoreduction and two who had complete clinical and histological remission. In the five patients with eosinophilia, three had complete clinical and haematological remission. The other two, who did not respond to treatment, were the only patients with the ckit D816V mutation. Our results suggest that imatinib either inhibits the growth-promoting role of wild type ckit, or targets an oncogenic kinase.
Assuntos
Antineoplásicos/uso terapêutico , Mastocitose Sistêmica/tratamento farmacológico , Piperazinas/uso terapêutico , Proteínas Proto-Oncogênicas c-kit/efeitos dos fármacos , Pirimidinas/uso terapêutico , Adulto , Benzamidas , Esquema de Medicação , Humanos , Mesilato de Imatinib , Mastocitose Sistêmica/enzimologia , Mastocitose Sistêmica/genética , Mutação , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-kit/genética , Resultado do TratamentoRESUMO
With the exception of chronic myeloid leukemia (CML), chronic myeloproliferative disorders (CMPDs) are a heterogeneous spectrum of conditions for which the molecular pathogenesis is not well understood. Most cases have a normal or aneuploid karyotype, but a minority present with a reciprocal translocation that disrupts specific tyrosine kinase genes, most commonly PDGFRB or FGFR1. These translocations result in the production of constitutively active tyrosine kinase fusion proteins that deregulate hemopoiesis in a manner analogous to BCR-ABL. With the advent of targeted signal transduction therapy, an accurate clinical and molecular diagnosis of CMPDs has become increasingly important. Currently, patients with PDGFRB or ABL fusion genes are candidates for treatment with Imatinib (STI571), but it is likely that alternative strategies will be necessary for the treatment of most other patients.
Assuntos
Transtornos Mieloproliferativos/genética , Proteínas Tirosina Quinases/genética , Translocação Genética , Doença Crônica , Humanos , Transtornos Mieloproliferativos/enzimologia , Proteínas de Fusão Oncogênica , Proteínas Tirosina Quinases/metabolismo , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/metabolismo , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos , Receptor beta de Fator de Crescimento Derivado de Plaquetas/genética , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptores de Fatores de Crescimento de Fibroblastos/genética , Receptores de Fatores de Crescimento de Fibroblastos/metabolismo , Transdução de SinaisRESUMO
The t(4;14)(p16.3;q32), associated with 10-20% of cases of multiple myeloma (MM), deregulates the expression of MMSET and FGFR3. To assess the potential of FGFR3 as a drug target, we evaluated the effects of selective inhibitors on MM and control cell lines. SU5402 and PD173074 specifically inhibited the growth of the two t(4;14)-positive MM lines, KMS-11 and OPM-2. Importantly, inhibition was still observed in the presence of IL-6, a growth factor known to play an important role in MM. Both compounds induced a dose-dependent reduction in cell viability and an increase in apoptosis, accompanied by a decrease in extracellular signal-related kinase phosphorylation. In contrast, no inhibition was seen with either compound against t(4;14)-negative cell lines or NCI-H929, a t(4;14)-positive, FGFR3-negative MM cell line. FGFR3 is thus a plausible candidate for targeted therapy in a subset of MM patients.