RESUMO
Acute erythroleukemia (AEL or acute myeloid leukemia [AML]-M6) is a rare but aggressive hematologic malignancy. Previous studies showed that AEL leukemic cells often carry complex karyotypes and mutations in known AML-associated oncogenes. To better define the underlying molecular mechanisms driving the erythroid phenotype, we studied a series of 33 AEL samples representing 3 genetic AEL subgroups including TP53-mutated, epigenetic regulator-mutated (eg, DNMT3A, TET2, or IDH2), and undefined cases with low mutational burden. We established an erythroid vs myeloid transcriptome-based space in which, independently of the molecular subgroup, the majority of the AEL samples exhibited a unique mapping different from both non-M6 AML and myelodysplastic syndrome samples. Notably, >25% of AEL patients, including in the genetically undefined subgroup, showed aberrant expression of key transcriptional regulators, including SKI, ERG, and ETO2. Ectopic expression of these factors in murine erythroid progenitors blocked in vitro erythroid differentiation and led to immortalization associated with decreased chromatin accessibility at GATA1-binding sites and functional interference with GATA1 activity. In vivo models showed development of lethal erythroid, mixed erythroid/myeloid, or other malignancies depending on the cell population in which AEL-associated alterations were expressed. Collectively, our data indicate that AEL is a molecularly heterogeneous disease with an erythroid identity that results in part from the aberrant activity of key erythroid transcription factors in hematopoietic stem or progenitor cells.
Assuntos
Leucemia Eritroblástica Aguda/genética , Proteínas de Neoplasias/fisiologia , Fatores de Transcrição/fisiologia , Transcriptoma , Adulto , Animais , Transformação Celular Neoplásica/genética , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/fisiologia , Dioxigenases , Eritroblastos/metabolismo , Eritropoese/genética , Feminino , Fator de Transcrição GATA1/deficiência , Fator de Transcrição GATA1/genética , Técnicas de Introdução de Genes , Heterogeneidade Genética , Células-Tronco Hematopoéticas/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Transgênicos , Pessoa de Meia-Idade , Mutação , Proteínas de Neoplasias/genética , Células-Tronco Neoplásicas/metabolismo , Proteínas Proto-Oncogênicas/deficiência , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/fisiologia , RNA-Seq , Quimera por Radiação , Proteínas Repressoras/genética , Proteínas Repressoras/fisiologia , Fatores de Transcrição/genética , Regulador Transcricional ERG/genética , Regulador Transcricional ERG/fisiologia , Sequenciamento do Exoma , Adulto JovemRESUMO
Secondary acute myeloid leukemia (sAML) after myelodysplastic or myeloproliferative disorders is a high-risk category currently identified by clinical history or specific morphological and cytogenetic abnormalities. However, in the absence of these features, uncertainties remain to identify the secondary nature of some cases otherwise defined as de novo AML. To test whether a chromatin-spliceosome (CS) mutational signature might better inform the definition of the de novo AML group, we analyzed a prospective cohort of 413 newly diagnosed AML patients enrolled into a randomized clinical trial (NILG AML 02/06) and provided with accurate cytogenetic and molecular characterization. Among clinically defined de novo AML, 17.6% carried CS mutations (CS-AML) and showed clinical characteristics closer to sAML (older age, lower white blood cell counts and higher rate of multilineage dysplasia). Outcomes in this group were adverse, more similar to those of sAML as compared to de novo AML (overall survival, 30% in CS-AML and 17% in sAML vs 61% in de novo AML, P<0.0001; disease free survival, 26% in CS-AML and 22% in sAML vs 54% of de novo AML, P<0.001) and independently confirmed by multivariable analysis. Allogeneic transplant in first complete remission improved survival in both sAML and CS-AML patients. In conclusion, these findings highlight the clinical significance of identifying CS-AML for improved prognostic prediction and potential therapeutic implications. (NILG AML 02/06: ClinicalTrials.gov Identifier: NCT00495287).
Assuntos
Leucemia Mieloide Aguda , Transtornos Mieloproliferativos , Idoso , Cromatina/genética , Humanos , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/epidemiologia , Leucemia Mieloide Aguda/genética , Prognóstico , Estudos Prospectivos , SpliceossomosRESUMO
The 2016 revision of the World Health Organization (WHO) classification of myeloproliferative neoplasms defines 2 stages of primary myelofibrosis (PMF): prefibrotic/early (pre-PMF) and overt fibrotic (overt PMF) phase. In this work, we studied the clinical and molecular features of patients belonging to these categories of PMF. The diagnosis of 661 PMF patients with a bone marrow biopsy at presentation was revised according to modern criteria; clinical information and annotation of somatic mutations in both driver and selected nondriver myeloid genes were available for all patients. Compared with pre-PMF, overt PMF was enriched in patients with anemia, thrombocytopenia, leukopenia, higher blast count, symptoms, large splenomegaly, and unfavorable karyotype. The different types of driver mutations were similarly distributed between the 2 categories, whereas selected mutations comprising the high mutation risk (HMR) category (any mutations in ASXL1, SRSF2, IDH1/2, EZH2) were more represented in overt PMF. More patients with overt PMF were in higher International Prognostic Scoring System risk categories at diagnosis, and the frequency increased during follow-up, suggesting greater propensity to disease progression compared with pre-PMF. Median survival was significantly shortened in overt PMF (7.2 vs 17.6 years), with triple negativity for driver mutations and presence of HMR mutations representing independent predictors of unfavorable outcome. The findings of this "real-life" study indicate that adherence to 2016 WHO criteria allows for identification of 2 distinct categories of patients with PMF where increased grades of fibrosis are associated with more pronounced disease manifestations, adverse mutation profile, and worse outcome, overall suggesting they might represent a phenotypic continuum.
Assuntos
Mutação , Mielofibrose Primária , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Intervalo Livre de Doença , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Feminino , Humanos , Isocitrato Desidrogenase/genética , Masculino , Pessoa de Meia-Idade , Mielofibrose Primária/genética , Mielofibrose Primária/mortalidade , Proteínas Repressoras/genética , Fatores de Processamento de Serina-Arginina/genética , Taxa de Sobrevida , Organização Mundial da SaúdeRESUMO
Splenic hematopoiesis is a major feature in the course of myelofibrosis (MF). In fact, the spleen of patients with MF contains malignant hematopoietic stem cells retaining a complete differentiation program, suggesting both a pivotal role of the spleen in maintaining the disease and a tight regulation of hematopoiesis by the splenic microenvironment, in particular by mesenchymal stromal cells (MSCs). Little is known about splenic MSCs (Sp-MSCs), both in normal and in pathological context. In this work, we have in vitro expanded and characterized Sp-MSCs from 25 patients with MF and 13 healthy subjects (HS). They shared similar phenotype, growth kinetics, and differentiation capacity. However, MF Sp-MSCs expressed significant lower levels of nestin, and favored megakaryocyte (Mk) differentiation in vitro at a larger extent than their normal counterpart. Moreover, they showed a significant upregulation of matrix metalloprotease 2 (MMP2) and fibronectin 1 (FN1) genes both at mRNA expression and at protein level, and, finally, developed genetic abnormalities which were never detected in HS-derived Sp-MSCs. Our data point toward the existence of a defective splenic niche in patients with MF that could be responsible of some pathological features of the disease, including the increased trafficking of CD34+ cells and the expansion of the megakaryocytic lineage.
Assuntos
Células-Tronco Mesenquimais/patologia , Mielofibrose Primária/patologia , Baço/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD34 , Estudos de Casos e Controles , Movimento Celular , Proliferação de Células , Feminino , Fibronectinas/metabolismo , Hematopoese , Humanos , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Megacariócitos/patologia , Pessoa de Meia-Idade , Nestina/metabolismo , Adulto JovemRESUMO
Primary myelofibrosis (PMF) is a Myeloproliferative Neoplasm (MPN) characterized by megakaryocyte hyperplasia, progressive bone marrow fibrosis, extramedullary hematopoiesis and transformation to Acute Myeloid Leukemia (AML). A number of phenotypic driver (JAK2, CALR, MPL) and additional subclonal mutations have been described in PMF, pointing to a complex genomic landscape. To discover novel genomic lesions that can contribute to disease phenotype and/or development, gene expression and copy number signals were integrated and several genomic abnormalities leading to a concordant alteration in gene expression levels were identified. In particular, copy number gain in the polyamine oxidase (PAOX) gene locus was accompanied by a coordinated transcriptional up-regulation in PMF patients. PAOX inhibition resulted in rapid cell death of PMF progenitor cells, while sparing normal cells, suggesting that PAOX inhibition could represent a therapeutic strategy to selectively target PMF cells without affecting normal hematopoietic cells' survival. Moreover, copy number loss in the chromatin modifier HMGXB4 gene correlates with a concomitant transcriptional down-regulation in PMF patients. Interestingly, silencing of HMGXB4 induces megakaryocyte differentiation, while inhibiting erythroid development, in human hematopoietic stem/progenitor cells. These results highlight a previously un-reported, yet potentially interesting role of HMGXB4 in the hematopoietic system and suggest that genomic and transcriptional imbalances of HMGXB4 could contribute to the aberrant expansion of the megakaryocytic lineage that characterizes PMF patients.
Assuntos
Dosagem de Genes , Proteína HMGB2/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/genética , Mielofibrose Primária/genética , Aberrações Cromossômicas , Eletroporação , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transcriptoma , Poliamina OxidaseRESUMO
Primary myelofibrosis (PMF) is a myeloproliferative neoplasm characterized by megakaryocyte (MK) hyperplasia, bone marrow fibrosis, and abnormal stem cell trafficking. PMF may be associated with somatic mutations in JAK2, MPL, or CALR. Previous studies have shown that abnormal MKs play a central role in the pathophysiology of PMF. In this work, we studied both gene and microRNA (miRNA) expression profiles in CD34(+) cells from PMF patients. We identified several biomarkers and putative molecular targets such as FGR, LCN2, and OLFM4. By means of miRNA-gene expression integrative analysis, we found different regulatory networks involved in the dysregulation of transcriptional control and chromatin remodeling. In particular, we identified a network gathering several miRNAs with oncogenic potential (eg, miR-155-5p) and targeted genes whose abnormal function has been previously associated with myeloid neoplasms, including JARID2, NR4A3, CDC42, and HMGB3. Because the validation of miRNA-target interactions unveiled JARID2/miR-155-5p as the strongest relationship in the network, we studied the function of this axis in normal and PMF CD34(+) cells. We showed that JARID2 downregulation mediated by miR-155-5p overexpression leads to increased in vitro formation of CD41(+) MK precursors. These findings suggest that overexpression of miR-155-5p and the resulting downregulation of JARID2 may contribute to MK hyperplasia in PMF.
Assuntos
Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Células-Tronco Hematopoéticas/metabolismo , MicroRNAs/genética , Mielofibrose Primária/genética , RNA Mensageiro/genética , Antígenos CD34/metabolismo , Diferenciação Celular/genética , Linhagem da Célula/genética , Redes Reguladoras de Genes , Inativação Gênica , Granulócitos/metabolismo , Células-Tronco Hematopoéticas/citologia , Humanos , Megacariócitos/citologia , Megacariócitos/metabolismo , Complexo Repressor Polycomb 2/genética , Interferência de RNA , Reprodutibilidade dos Testes , Trombopoese/genéticaRESUMO
Transformation to secondary myelofibrosis (MF) occurs as part of the natural history of polycythemia vera (PPV-MF) and essential thrombocythemia (PET-MF). Although primary (PMF) and secondary MF are considered similar diseases and managed similarly, there are few studies specifically focused on the latter. The aim of this study was to characterize the mutation landscape, and describe the main clinical correlates and prognostic implications of mutations, in a series of 359 patients with PPV-MF and PET-MF. Compared with PV and ET, the JAK2V617F and CALR mutated allele burden was significantly higher in PPV-MF and/or PET-MF, indicating a role for accumulation of mutated alleles in the process of transformation to MF. However, neither the allele burden nor the type of driver mutation influenced overall survival (OS), while absence of any driver mutation (triple negativity) was associated with significant reduction of OS in PET-MF, similar to PMF. Of the five interrogated subclonal mutations (ASXL1, EZH2, SRSF2, IDH1, and IDH2), that comprise a prognostically detrimental high molecular risk (HMR) category in PMF, only SRSF2 mutations were associated with reduced survival in PET-MF, and no additional mutation profile with prognostic relevance was highlighted. Overall, these data indicate that the molecular landscape of secondary forms of MF is different from PMF, suggesting that unknown mutational events might contribute to the progression from chronic phase disease to myelofibrosis. These findings also support more extended genotyping approaches aimed at identifying novel molecular abnormalities with prognostic relevance for patients with PPV-MF and PET-MF. Am. J. Hematol. 91:681-686, 2016. © 2016 Wiley Periodicals, Inc.
Assuntos
Mutação , Transtornos Mieloproliferativos/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos Mieloproliferativos/epidemiologia , Transtornos Mieloproliferativos/mortalidade , Transtornos Mieloproliferativos/patologia , Policitemia Vera/genética , Policitemia Vera/mortalidade , Policitemia Vera/patologia , Mielofibrose Primária/epidemiologia , Mielofibrose Primária/etiologia , Mielofibrose Primária/genética , Mielofibrose Primária/mortalidade , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Trombocitemia Essencial/genética , Trombocitemia Essencial/mortalidade , Trombocitemia Essencial/patologiaRESUMO
The prognostic significance of bone marrow (BM) fibrosis grade in patients with primary myelofibrosis (PMF) is still debated. A fibrosis grade greater than 1 was shown to associate with higher risk of death, and addition of fibrosis grade to IPSS score resulted in a more accurate prediction of survival. The aim of this study was to analyze the prognostic impact of BM fibrosis in 490 patients with PMF, evaluated at diagnosis, molecularly annotated and with extensive follow-up information. We found that fibrosis grade 2 and greater on a 0-3 scale was associated with clinical characteristics indicative of a more advanced disease, such as anemia, leukopenia, thrombocytopenia, constitutional symptoms, larger splenomegaly and a higher IPSS risk category. Patients with higher grade of fibrosis were also more likely to have additional somatic mutations in ASXL1 and EZH2, that are prognostically adverse. Median survival was significantly reduced in patients with grade 2 and 3 fibrosis as compared with grade 1; this effect was maintained when analysis was restricted to younger patients. In multivariate analysis, fibrosis grade independently predicted for survival regardless of IPSS variables and mutational status; the adverse impact of fibrosis was noticeable especially in lower IPSS risk categories. Overall, results indicate that higher grades of fibrosis correlate with unique clinical and molecular aspects and represent an independent adverse variable in patients with PMF; these observations deserve confirmation in prospectively designed series of patients. Am. J. Hematol. 91:918-922, 2016. © 2016 Wiley Periodicals, Inc.
Assuntos
Mielofibrose Primária/diagnóstico , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Anemia/etiologia , Contagem de Células Sanguíneas , Feminino , Hemoglobinas/análise , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Mielofibrose Primária/complicações , Mielofibrose Primária/genética , Mielofibrose Primária/mortalidade , Prognóstico , Esplenomegalia/etiologia , Trombocitopenia/etiologia , Adulto JovemRESUMO
Allogeneic hematopoietic stem cell transplantation (HSCT) remains the only curative option for patients with Myelodysplastic syndromes (MDS). For many years, the selection of patients to allogeneic HSCT has been largely based on use of the International Prognostic Scoring System-Revised (IPSS-R). However, the recent broader application of next generation sequencing in clinical practice provided an abundance of molecular data and led to the introduction of molecular prognostic scores as IPSS-Molecular (IPSS-M). In this paper, we retrospectively analyzed the outcomes of 57 consecutive MDS patients treated with allogeneic HSCT in our center. Re-stratification from IPSS-R to IPSS-M occurred in almost half of patients. The application of IPSS-M to our cohort demonstrated a stronger prognostic separation compared to IPSS-R and improved the C-index. Very high-risk IPSS-M patients showed worse outcomes following HSCT compared to high-risk patients. This study provides data supporting the need of integrating molecular information in the transplant decision making of patients with MDS. This allows an earlier and better identification of patients to whom the transplant should be advised.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Síndromes Mielodisplásicas , Humanos , Síndromes Mielodisplásicas/terapia , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/mortalidade , Síndromes Mielodisplásicas/diagnóstico , Estudos Retrospectivos , Transplante de Células-Tronco Hematopoéticas/métodos , Masculino , Feminino , Pessoa de Meia-Idade , Prognóstico , Idoso , Adulto , Tomada de Decisão Clínica , Transplante Homólogo , Sequenciamento de Nucleotídeos em Larga Escala , Adulto JovemRESUMO
Transcriptional cofactors of the ETO family are recurrent fusion partners in acute leukemia. We characterized the ETO2 regulome by integrating transcriptomic and chromatin binding analyses in human erythroleukemia xenografts and controlled ETO2 depletion models. We demonstrate that beyond its well-established repressive activity, ETO2 directly activates transcription of MYB, among other genes. The ETO2-activated signature is associated with a poorer prognosis in erythroleukemia but also in other acute myeloid and lymphoid leukemia subtypes. Mechanistically, ETO2 colocalizes with EP300 and MYB at enhancers supporting the existence of an ETO2/MYB feedforward transcription activation loop (e.g., on MYB itself). Both small-molecule and PROTAC-mediated inhibition of EP300 acetyltransferases strongly reduced ETO2 protein, chromatin binding, and ETO2-activated transcripts. Taken together, our data show that ETO2 positively enforces a leukemia maintenance program that is mediated in part by the MYB transcription factor and that relies on acetyltransferase cofactors to stabilize ETO2 scaffolding activity.
RESUMO
BACKGROUND: The identification of the JAK2V617F mutation is mandatory in the diagnostic work-up of Philadelphia chromosome-negative myeloproliferative neoplasms. Several molecular techniques to detect this mutation are currently available, but each of them has some limits. DESIGN AND METHODS: We set up a novel molecular method for the identification of the JAK2V617F mutation based on an allele-specific loop-mediated amplification, not polymerase chain reaction analysis. This innovative technique amplifies DNA targets under isothermal conditions with high specificity, efficiency and rapidity. The method does not require either a thermal cycler or gel separation and the DNA amplification reaction is visible to the naked eye and can be monitored by turbidimetry. This method was validated on DNA from cell lines as well as from patients with myeloproliferative neoplasms. The results were compared with those obtained by conventional polymerase chain reaction methods. RESULTS: This assay detects, within 1 hour, the JAK2V617F mutation down to an allele burden of 0.1-0.01%. All samples positive by polymerase chain reaction (n=146) proved positive when tested by allele-specific loop-mediated amplification and none of the 80 negative controls gave false positive results. In addition, six patients with essential thrombocythemia previously diagnosed as being JAK2V617F negative by polymerase chain reaction analysis were found to be positive (at a low level) by allele-specific loop-mediated amplification. Furthermore, this assay discriminated the amount of JAK2V617F tumor allele within intervals of positivity, above 50%, between 50% and 10% and below 10%. CONCLUSIONS: Allele-specific loop-mediated amplification is a simple, robust and easily applicable method for the molecular diagnosis and monitoring of JAK2V617F mutation in patients with chronic myeloproliferative neoplasms.
Assuntos
Bioensaio , DNA/análise , Janus Quinase 2/genética , Mutação/genética , Transtornos Mieloproliferativos/diagnóstico , Técnicas de Amplificação de Ácido Nucleico/métodos , Alelos , Estudos de Casos e Controles , Doença Crônica , DNA/genética , Humanos , Transtornos Mieloproliferativos/genética , Células Tumorais CultivadasRESUMO
Patients with Philadelphia-negative myeloproliferative neoplasms are at high risk of thrombotic events (TEs). Predisposing factors have been identified in essential thrombocythemia (ET), polycythemia vera (PV) and primary myelofibrosis (primary MF, PMF), while yet not recognized in post PV/ET-MF (known as secondary MF, SMF). Within the 1258 SMF of the MYSEC (MYelofibrosis SECondary to PV and ET) dataset, 135 (10.7%) developed a TE at a median follow-up of 3.5 years (range, 1-21.4), with an incidence of 2.3% patients per year. Venous events accounted for two-thirds of the total. Cox multivariable analysis, supported by Fine-Gray models with death as competitive risk, showed that being on cytoreductive therapy at time of SMF evolution is associated with an absolute risk reduction of thrombosis equal to 3.3% within 3 years. Considering individually cytoreductive therapies, univariate regression model found that both conventional cytoreduction, mainly hydroxyurea, (HR 0.41, 95% CI: 0.26-0.65, p = 0.0001) and JAK inhibitors, mostly ruxolitinib, (HR 0.50, 95% CI: 0.24-1.02, p = 0.05) were associated with fewer thrombosis. Our study informs treating physicians of a non-low incidence of TEs in post PV/ET-MF and of the potential protective role of cytoreductive therapy in terms of thrombotic events.
Assuntos
Inibidores de Janus Quinases , Policitemia Vera , Mielofibrose Primária , Trombocitemia Essencial , Trombose , Humanos , Hidroxiureia/uso terapêutico , Policitemia Vera/complicações , Policitemia Vera/terapia , Mielofibrose Primária/etiologia , Mielofibrose Primária/terapia , Trombocitemia Essencial/complicações , Trombose/etiologiaAssuntos
Calreticulina/genética , Janus Quinase 2/genética , Trombocitemia Essencial/complicações , Trombose/etiologia , Trombose/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Prognóstico , Fatores de Risco , Trombocitemia Essencial/genética , Trombose/diagnósticoRESUMO
We tested the hypothesis that levels of pentraxin high sensitivity C-reactive protein and pentraxin 3 might be correlated with cardiovascular complications in patients with essential thrombocythemia and polycythemia vera. High sensitivity C-reactive protein and pentraxin 3 were measured in 244 consecutive essential thrombocythemia and polycythemia vera patients in whom, after a median follow up of 5.3 years (range 0-24), 68 cardiovascular events were diagnosed. The highest C-reactive protein tertile was compared with the lowest (>3 vs. <1 mg/L) and correlated with age (P=0.001), phenotype (polycythemia vera vs. essential thrombocythemia, P=0.006), cardiovascular risk factors (P=0.012) and JAK2V617F allele burden greater than 50% (P=0.003). Major thrombosis rate was higher in the highest C-reactive protein tertile (P=0.01) and lower at the highest pentraxin 3 levels (P=0.045). These associations remained significant in multivariate analyses and indicate that blood levels of high sensitivity C-reactive protein and petraxin 3 independently and in opposite ways modulate the intrinsic risk of cardiovascular events in patients with myeloproliferative disorders.
Assuntos
Proteína C-Reativa/metabolismo , Inflamação/diagnóstico , Policitemia Vera/complicações , Componente Amiloide P Sérico/metabolismo , Trombocitemia Essencial/complicações , Trombose/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Ensaio de Imunoadsorção Enzimática , Feminino , Seguimentos , Humanos , Inflamação/etiologia , Inflamação/metabolismo , Janus Quinase 2/genética , Masculino , Pessoa de Meia-Idade , Mutação/genética , Policitemia Vera/sangue , Policitemia Vera/terapia , Prognóstico , Fatores de Risco , Taxa de Sobrevida , Trombocitemia Essencial/sangue , Trombocitemia Essencial/terapia , Trombose/etiologia , Trombose/metabolismo , Adulto JovemAssuntos
Mutação , Leucemia-Linfoma Linfoblástico de Células Precursoras , Proteína Supressora de Tumor p53/genética , Adulto , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Taxa de SobrevidaRESUMO
The platelet contribution to the thrombophilic state of patients with myeloproliferative neoplasms (MPNs), i.e., essential thrombocythemia (ET) and polycythemia vera (PV), remains uncertain. In this study we aimed to characterize the thrombin generation (TG) potential expressed by platelets from these subjects, compare it to normal platelets, and identify what factors might be responsible for platelet TG. In a group of 140 MPN patients (80 ET and 60 PV) and 72 healthy subjects, we measured the global procoagulant potential of platelet-rich plasma (PRP) utilizing the TG assay by the calibrated automated thrombogram (CAT). To characterize the procoagulant contribution of platelets in PRP, the TG of both isolated platelets and platelet-poor plasma was measured, and the platelet surface expression of TF was determined. Finally, the activation status of platelets was assessed by the levels of P-selectin expressed on platelet surface. MPN patients had significantly increased PRP and isolated platelet TG potential compared to controls. This was associated to the occurrence of platelet activation. Patients carriers of the JAK2V617F mutation showed the highest values of TG and platelet surface TF and P-selectin. Platelet TG potential was significantly lower in hydroxyurea(HU) compared to non-HU-treated patients and was lowest in HU-treated JAK2V617F carriers. In subjects not receiving HU, platelet TG significantly increased by JAK2V617F allele burden increment (P < 0.05).This study demonstrates a platelet-dependent form of hypercoagulability in MPN patients, particularly in those carriers of the JAK2V617F mutation. The cytoreductive therapy with HU significantly affects this prothrombotic phenotype.
Assuntos
Plaquetas/metabolismo , Policitemia Vera/sangue , Trombina/biossíntese , Trombocitemia Essencial/sangue , Adulto , Idoso , Testes de Coagulação Sanguínea , Plaquetas/citologia , Estudos de Casos e Controles , Feminino , Citometria de Fluxo , Humanos , Janus Quinase 2/genética , Masculino , Pessoa de Meia-Idade , Mutação , Contagem de Plaquetas , Plasma Rico em Plaquetas , Policitemia Vera/metabolismo , Trombocitemia Essencial/metabolismoRESUMO
SARS-COV2 pandemic has caused profound challenges in health care systems worldwide. Patients affected by hematological neoplasms appear to be particularly at risk of developing COVID-19 complications, with unfavorable outcomes. Here, we present the case of a 57-years-old woman diagnosed with severe COVID-19 pneumonia and concurrent acute myeloid leukemia (AML). At the time of diagnosis, it was decided to postpone leukemia therapy to enable adequate COVID-19 pneumonia treatment. When her conditions related to pneumonia improved, the combination of Azacitidine-Venetoclax was used as first-line treatment instead of conventional intensive chemotherapy. At the end of the first two cycles, the patient showed complete remission, and a post-remission consolidation with allogeneic hematopoietic stem cell transplantation has been planned. This case suggests that Azacytidine-Venetoclax induction may represent a valid and safe alternative to intensive chemotherapy in the challenging setting of patients with a concomitant diagnosis of AML and severe COVID-19 infection.
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We report the isolation of two human IgG1k monoclonal antibodies (mAbs) directed against the SARS-CoV-2 spike protein. These mAbs were isolated from two donors who had recovered from COVID-19 infection during the first pandemic peak in the Lombardy region of Italy, the first European and initially most affected region in March 2020. We used the method of EBV immortalization of purified memory B cells and supernatant screening with a spike S1/2 assay for mAb isolation. This method allowed rapid isolation of clones, with one donor showing about 7% of clones positive against spike protein, whereas the other donor did not produce positive clones out of 91 tested. RNA was extracted from positive clones 39-47 days post-EBV infection, allowing VH and VL sequencing. The same clones were sequenced again after a further 100 days in culture, showing that no mutation had taken place during in vitro expansion. The B cell clones could be expanded in culture for more than 4 months after EBV immortalization and secreted the antibodies stably during that time, allowing to purify mg quantities of each mAb for functional assays without generating recombinant proteins. Unfortunately, neither mAb had significant neutralizing activity in a virus infection assay with several different SARS-CoV-2 isolates. The antibody sequences are made freely available.
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Long non-coding RNAs (lncRNAs) have been recently described as key mediators in the development of hematological malignancies. In the last years, circulating lncRNAs have been proposed as a new class of non-invasive biomarkers for cancer diagnosis and prognosis and to predict treatment response. The present study is aimed to investigate the potential of circulating lncRNAs as non-invasive prognostic biomarkers in myelofibrosis (MF), the most severe among Philadelphia-negative myeloproliferative neoplasms. We detected increased levels of seven circulating lncRNAs in plasma samples of MF patients (n = 143), compared to healthy controls (n = 65). Among these, high levels of LINC01268, MALAT1 or GAS5 correlate with detrimental clinical variables, such as high count of leukocytes and CD34+ cells, severe grade of bone marrow fibrosis and presence of splenomegaly. Strikingly, high plasma levels of LINC01268 (p = 0.0018), GAS5 (p = 0.0008) or MALAT1 (p = 0.0348) are also associated with a poor overall-survival while high levels of LINC01268 correlate with a shorter leukemia-free-survival. Finally, multivariate analysis demonstrated that the plasma level of LINC01268 is an independent prognostic variable, suggesting that, if confirmed in future in an independent patients' cohort, it could be used for further studies to design an updated classification model for MF patients.
RESUMO
Myelofibrosis (MF) belongs to the family of classic Philadelphia-negative myeloproliferative neoplasms (MPNs). It can be primary myelofibrosis (PMF) or secondary myelofibrosis (SMF) evolving from polycythemia vera (PV) or essential thrombocythemia (ET). Despite the differences, PMF and SMF patients are currently managed in the same way, and prediction of survival is based on the same clinical and genetic features. In the last few years, interest has grown concerning the ability of gene expression profiles (GEPs) to provide valuable prognostic information. Here, we studied the GEPs of granulocytes from 114 patients with MF, using a microarray platform to identify correlations with patient characteristics and outcomes. Cox regression analysis led to the identification of 201 survival-related transcripts characterizing patients who are at high risk for death. High-risk patients identified by this gene signature displayed an inferior overall survival and leukemia-free survival, together with clinical and molecular detrimental features included in contemporary prognostic models, such as the presence of high molecular risk mutations. The high-risk group was enriched in post-PV and post-ET MF and JAK2V617F homozygous patients, whereas pre-PMF was more frequent in the low-risk group. These results demonstrate that GEPs in MF patients correlate with their molecular and clinical features, particularly their survival, and represent the proof of concept that GEPs might provide complementary prognostic information to be applied in clinical decision making.