Project description:The activation of PD-1 (Programmed Death receptor-1) on T cells can cause T cell exhaustion and immune tolerance. Some tumors up-regulate the expression of the ligand of PD-1, namely PD-L1 (Programmed Death Receptor-Ligand 1), thus preventing anti-tumor immune response and promoting immune-escape. Previous studies have shown that JAK2 (Janus Kinase 2) signaling can promote PD-L1 expression in Hodgkin Lymphoma. In Myeloproliferative Neoplasms (MPN), JAK2 is frequently characterized by the the presence of the point-mutation V617F, which leads to its constitutive activation and to uncontrolled cell proliferation and survival. Accordingly, tumor cell lines expressing JAK2 V617F express higher levels of PD-L1 as compared to tumor cell lines negative for such mutations. In this experiment, we transfected BaF3 cells with a vector (plasmid for Murine Stem Cell Virus) containing the gene for JAK2 with the point-mutation V617F. As control, we used BaF3 cells transfected with the same vector, but without the gene for JAK2 V617F (empty vector). Both the cell lines (with/without JAK2 V617F) were co-cultured with primary murine T cells. When co-cultured with BaF3 cells expressing JAK2 V617F, T cells upregulated genes connected to senescence pathways, showed increased apoptosis, less cytokine production, and displayed other forms of dysfunction which can be associated with the activation of PD-1.
Project description:An increased number of circulating CD34+ hematopoietic progenitors (HP) and a prominent amplification of dystrophic megakaryocytes (MK) are observed in PMF patients. As transcriptome data from CD34+ hematopoietic progenitors showed modulations of FLT3 and MAP kinase expression independently of the JAK2V617F mutation status Transcriptome analysis was performed on circulating CD34+ cells from PMF patients using Agilent 22K microarray and compared to CD34+ cells from blood and bone marrow from un-mobilized healthy donors. Indirect map: each tested sample was hybridzed with reference probe
Project description:Polycythemia vera (PV) is a myeloproliferative disorder arising in pluripotent stem cells that causes an abnormal erythrocyte mass. More than 90% of PV patients have a mutation in JAK2 protein that is closely associated with the erythrocyte membrane. We report findings on quantitative analysis of the erythrocyte membrane proteins differentially regulated in PV patients treated with hydroxycarbamide.</br>Kottahachchi et al., EuPA Open Proteomics 7, 43-53</br>Quantitative analysis of the erythrocyte membrane proteins in polycythemia vera patients treated with hydroxycarbamide</br>DOI:10.1016/j.euprot.2015.04.001</br><a href="http://www.sciencedirect.com/science/article/pii/S2212968515000100">http://www.sciencedirect.com/science/article/pii/S2212968515000100</a>
Project description:The dataset contains microarray data from six patients diagnosed with essential thrombocythemia or myelofibrosis. The dataset was created in order to study the presence of copy number abnormalities or copy number neutral losses of heterozygosity in the genomes of the tumor tissue of these 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; 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:Comparison of ATG gene family members in MPN pattients with normal controls One-Way ANOVA while contrasting ATG gene family members in 11 Normal (Control) with either 1) 13 PV samples 2) 24 ET samples or 3) 18 PMF samples
Project description:Myelofibrosis is often associated with the myeloproliferative neoplasms and expression of oncogenic JAK2 mutants. Patients with myelofibrosis have diminished quality of life due to systemic symptoms arising from fibrotic changes in the bone marrow. The introduction of the JAK2 inhibitor, ruxolitinib, has been of benefit in the treatment of myelofibrosis patients however, it is not curative and there is still a requirement for new targeted therapies to eradicate the cells at the heart of myelofibrosis pathology. Repurposing drugs bypasses many of the hurdles present in drug development, such as toxicity and pharmacodynamic profiling. To this end we undertook a re-analysis of our pre-existing proteomic data sets to identify perturbed biochemical pathways and their associated drugs/inhibitors to potentially target the cells driving myelofibrosis. This approach identified CBL0137 as a candidate for targeting JAK2 mutant driven malignancies. We therefore assessed CBL0137 as a new agent to extinguish JAK2 mutant primitive cells and show its ability to preferentially target cells from MF patients compared to healthy control cells. Further we define its mechanistic action in primary haemopoietic progenitor cells and demonstrate its ability to reduce splenomegaly and reticulocyte number in a transgenic murine model of myeloproliferative neoplasms.
Project description:In this study, we evaluated the mechnasim of ruxolitinib action is directly on malignant cell or not. For this purpose, we evaluated whether the drug primarily blocks the proliferation of the malignant clone or exerts its effects also by targeting non-malignant cells. Therefore, we developed two JAK2-V617F-driven myeloproliferative neoplasm (MPN) mouse models harboring ruxolitinib resistance mutations. Mice carrying ruxolitinib-resistant JAK2-V617F-driven MPN responded to ruxolitinib treatment similar to mice with ruxolitinib-sensitive JAK2-V617F MPN with respect to reduction of spleen size, leukocyte count and pro-inflammatory cytokines in the serum. Ruxolitinib also reduced pro-inflammatory cytokines both in stromal cells and non-malignant hematopoietic cells. Using a rigorous ruxolitinib resistance mutation approach we can prove that ruxolitinib acts independent of oncogenic JAK2-V617F signaling and reduces the main features of MPN disease such as spleen size and leukocyte counts. Our findings characterize the mechanism of action for ruxolitinib in MPN.
Project description:In this study, we evaluated the mechnasim of ruxolitinib action is directly on malignant cell or not. For this purpose, we evaluated whether the drug primarily blocks the proliferation of the malignant clone or exerts its effects also by targeting non-malignant cells. Therefore, we developed two JAK2-V617F-driven myeloproliferative neoplasm (MPN) mouse models harboring ruxolitinib resistance mutations. Mice carrying ruxolitinib-resistant JAK2-V617F-driven MPN responded to ruxolitinib treatment similar to mice with ruxolitinib-sensitive JAK2-V617F MPN with respect to reduction of spleen size, leukocyte count and pro-inflammatory cytokines in the serum. Ruxolitinib also reduced pro-inflammatory cytokines both in stromal cells and non-malignant hematopoietic cells. Using a rigorous ruxolitinib resistance mutation approach we can prove that ruxolitinib acts independent of oncogenic JAK2-V617F signaling and reduces the main features of MPN disease such as spleen size and leukocyte counts. Our findings characterize the mechanism of action for ruxolitinib in MPN.
Project description:This experiment was designed to identify genes differentially expressed in association with the JAK2V617F mutation in polycythemia vera (PV) and essential thrombocythemia (ET). Peripheral blood was obtained from 20 ET and 16 PV patients and erythroid progenitors were grown in semi-solid methylcellulose media supplemented with 0.01 U/ml erythropoietin. Individual clones were plucked and genotyped for the presence of the JAK2V617F mutation, and up to 20 normal and mutant colonies were pooled from each patient, and subjected to expression profiling. In total, 72 expression profiling datasets were generated, representing paired samples of normal and mutant cells from 36 patients.