Project description:Polycythemia vera (PV) and essential thrombocythemia (ET) are Philadelphia-negative myeloproliferative neoplasms (MPNs) characterized by erythrocytosis and thrombocytosis, respectively. Approximately 95% of PV and 50–70% of ET patients harbour the V617F mutation in the exon 14 of JAK2 gene, while about 20-30% of ET patients carry CALRins5 or CALRdel52 mutations. These ET CARL-mutated subjects show higher platelet count and lower thrombotic risk compared to JAK2-mutated patients. Here we showed that CALR-mutated and JAK2V617F-positive CD34+ cells have different gene and miRNA expression profiles. Indeed, we highlighted several pathways differentially activated between JAK2V617F- and CALR-mutated progenitors, i.e. mTOR, MAPK/PI3K and MYC pathways. Furthermore, we unveiled that the expression of several genes involved in DNA repair, chromatin remodelling, splicing and chromatid cohesion are decreased in CALR-mutated cells. According to the low risk of thrombosis in CALR-mutated patients, we also found the down-regulation of several genes involved in thrombin signalling and platelet activation. As a whole, these data support the model in which CALR-mutated ET could be considered as a distinct disease entity from JAK2V617F-positive MPNs and may provide the molecular basis supporting the different clinical features of these patients.
Project description:Polycythemia vera (PV) and essential thrombocythemia (ET) are Philadelphia-negative myeloproliferative neoplasms (MPNs) characterized by erythrocytosis and thrombocytosis, respectively. Approximately 95% of PV and 50–70% of ET patients harbour the V617F mutation in the exon 14 of JAK2 gene, while about 20-30% of ET patients carry CALRins5 or CALRdel52 mutations. These ET CARL-mutated subjects show higher platelet count and lower thrombotic risk compared to JAK2-mutated patients. Here we showed that CALR-mutated and JAK2V617F-positive CD34+ cells have different gene and miRNA expression profiles. Indeed, we highlighted several pathways differentially activated between JAK2V617F- and CALR-mutated progenitors, i.e. mTOR, MAPK/PI3K and MYC pathways. Furthermore, we unveiled that the expression of several genes involved in DNA repair, chromatin remodelling, splicing and chromatid cohesion are decreased in CALR-mutated cells. According to the low risk of thrombosis in CALR-mutated patients, we also found the down-regulation of several genes involved in thrombin signalling and platelet activation. As a whole, these data support the model in which CALR-mutated ET could be considered as a distinct disease entity from JAK2V617F-positive MPNs and may provide the molecular basis supporting the different clinical features of these patients.
Project description:Philadelphia chromosome-negative myeloproliferative neoplasms (MPN) consist of primary myelofibrosis (PMF), polycythemia vera (PV), essential thrombocythemia (ET) In this dataset, we compare the gene expression data of patients JAK2V617F vs. CALR-mutated MPN patients.
Project description:A global microRNA expression profile was obtained from gradient-purified granulocytes (>95% pure) collected at the time of screening and at cycle 4 of treatment Protocol #18424-256 is a Phase 2 study of the JAK1 and JAK2 inhibitor INCB01842 in patients with advanced polycythemia vera (PV) and essential thrombocythemia (ET) refractory to hydroxyurea;
Project description:A global microRNA expression profile was obtained from gradient-purified granulocytes (>95% pure) collected at the time of screening and at cycle 4 of treatment Protocol #18424-256 is a Phase 2 study of the JAK1 and JAK2 inhibitor INCB01842 in patients with advanced polycythemia vera (PV) and essential thrombocythemia (ET) refractory to hydroxyurea; The aim was to to determine whether treatment with INC180424 was associated with changes in the global microRNA expression profile we compared granulocytes collected at baseline (screening) and at cycle 4
Project description:The project aims at comparing the effect of the JAK2V617F mutation on protein expression in human erythroid cells in the context of Polycythemia Vera and Essential Thrombocythemia
Project description:Primary mielofibrosis (PMF) is a rare chronic myeloproliferative disorder characterized by the accumulation of abnormal megakaryocytes (Mks) in the bone marrow (BM), variable degrees of BM fibrosis, osteosclerosis and angiogenesis, immature myeloid and erythroid cells, and tear-drop erythrocytes in the peripheral blood (PB), and extramedullary hematopoiesis. The identification of the JAK2V617F mutation represented a seminal discovery in the field of Philadelphia-chromosome–negative chronic myeloproliferative neoplasms (MPNs), providing clues to the pathogenesis, prompting a revision of the diagnostic criteria, and culminating in the development of clinical trials with JAK2 (and JAK1) inhibitors. The JAK2V617F mutation occurs in almost all patients with polycythemia vera (PV) and in 50%-70% of those with essential thrombocythemia (ET) and primary myelofibrosis (PMF). Soon after the identification of the JAK2V617F mutation, mutations in JAK2 exon 12 were described in rare patients with JAK2V617F-negative PV and mutations in MPL were reported in 5%-10% of ET or PMF subjects. The complexity of the molecular pathogenesis of MPNs is reinforced by discovery of additional mutations in TET2, ASXL1, CBL, IDH1/IDH2, EZH2 and IKZF1. These mutations are detected in a minority of patients at different phases of the disorder, including leukemic transformation, and are variably associated each other and with JAK2 or MPL mutations. In order to better characterize biological differences between mutated and wild-type PMF cell populations we performed a gene expression profiling on 9 samples carrying at least one mutation in ASXL1, SRSF2 or EZH2 genes and 11 wild-type samples using the Affymetrix GeneChip technology. After data preprocessing and filtering a supervised analysis approach was used to define a gene expression signature for mutated samples. PMF samples carrying at least one mutation in ASXL1, SRSF2 or EZH2 genes exhibit a specific molecular signature as compared with WT samples. Gene expression profile (GEP) of CD34+ cells from 20 PMF patients (1 replicate for each sample). In particular, GEP was performed on 9 samples carrying at least one mutation in ASXL1, SRSF2 or EZH2 genes and 11 wild-type samples.
Project description:Primary myelofibrosis (PMF) together with polycythemia vera (PV) and essential thrombocythemia (ET) belongs to the classic Philadelphia-negative myeloproliferative neoplasms (MPNs). PV and ET can evolve to secondary myelofibrosis (SMF) giving rise to post-PV (PPV) and post-ET (PET) myelofibrosis (MF). PMF and SMF patients are currently managed in the same way and prediction of survival is based on the same prognostic models, even if it has been demonstrated that they can’t accurately distinguish different risk categories in SMF. In the last few years interest grew concerning the ability of gene expression profiling (GEP) to provide valuable prognostic information for clinical decision making. To construct a molecular signature that can predict survival according to gene expression we studied GEP of granulocytes from 114 MF patients, including 35 prefibrotic/early PMF (Pre-PMF), 37 overt PMF (Overt-PMF), 26 PET and 16 PPV, using microarray platform.