Project description:Mutations in the endoplasmic reticulum (ER) chaperone calreticulin (CALR) are common in myeloproliferative neoplasm (MPN) patients, activate the thrombopoietin receptor (MPL), and mediate constitutive JAK/STAT signaling. The mechanisms by which CALR mutations cause myeloid transformation are incompletely defined. We employed mass spectrometry proteomics to identify novel CALR-mutant interacting proteins. Mutant CALR caused mislocalization of binding partners and increased recruitment of FLI1, ERP57 and CALR to the MPL promoter to enhance transcription. CALR 52 mutant was also found to increase genome-wide recruitment of Fli1 to the chromatin. Overall, these results show that type 1 CALR mutant modulates Fli1 cellular localization and recruitment.
Project description:This SuperSeries is composed of the following subset Series: GSE21948: High Density custom Agilent 44K CGH array analysis of 7q and TET2 region in myelodysplastic/myeloproliferative neoplasms GSE21990: Affymetrix SNP 6.0 array data for myelodysplastic/myeloproliferative neoplasms Refer to individual Series
Project description:Interferons (IFNs) are cytokines with potent anti-neoplastic properties and significant clinical activity in the treatment of myeloproliferative neoplasms (MPNs). The use of pegylated IFN for the treatment of MPNs has been of particular interest, with several clinical trials establishing clinical responses. Here we demonstrate that chromatin assembly factor 1 subunit B (CHAF1B) is overexpressed in MPN patients. Targeted silencing of CHAF1B enhances transcription of IFN-stimulated genes and promotes IFN-dependent anti-neoplastic effects against MPN patient-derived cells. Our findings suggest that targeting CHAF1B in combination with IFN therapy may offer an avenue for the development of effective combination therapies for the treatment of MPNs.
Project description:Cardiovascular events are the leading cause of death in patients with JAK2V617F myeloproliferative neoplasms. Their mechanisms are poorly understood. To investigate the role of microvesicles in these events, we performed a proteomic analysis of microvesicles derived from red blood cells from mice with a myeloproliferative neoplasms (Jak2V617F Flex/WT ;VE-cadherin-Cre) vs. littermate controls.
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:Calreticulin (CALR) mutations are frequent, disease-initiating events in myeloproliferative neoplasms (MPN). Although the biological mechanism by which CALR mutations cause MPN has been elucidated, there currently are no clonally selective therapies for CALR-mutant MPN. To identify unique genetic dependencies in CALR-mutant MPN, we performed a whole-genome CRISPR knockout depletion screen in mutant CALR-transformed hematopoietic cells. We found that genes in the N-glycosylation pathway (amongst others) were differentially depleted in mutant CALR-transformed cells as compared with control cells. Using a focused pharmacological screen targeting unique vulnerabilities uncovered in the CRISPR screen, we found that chemical inhibition of N-glycosylation impaired the growth of mutant CALR-transformed cells in vitro. We treated Calr-mutant knockin mice with the N-glycosylation inhibitor, 2-deoxy-glucose (2-DG), and found a preferential sensitivity of Calr-mutant cells to 2-DG as compared to wild-type cells, and a normalization of key MPN disease features. These findings advance the development of clonally selective treatments for CALR-mutant MPN.
Project description:Recurrent mutations in calreticulin (CALR) are present in 70-80% of JAK2 unmutated myeloproliferative neoplasms (MPN). Current models of CALR mutant MPNs are mainly based on cancer cell lines with ectopic overexpression or transgenic mouse models with a lack of data for primary human hematopoietic stem and progenitor cells (HSPCs) with endogenous CALR expression. Thus, we developed a CRISPR/Cas9 and AAV6-mediated knock-in approach to introduce the two most common CALR mutations (52 bp deletion, DEL; 5 bp insertion, INS) at the endogenous gene locus in human cord blood-derived HSPCs. We used these cells to investigate transcriptional changes induced upon CALR mutation acquisition in HSPCs in a prospective manner by performing RNA-sequencing 4 days after CRISPR-mediated knock-in.
Project description:Calreticulin (CALR) mutations are frequent, disease-initiating events in myeloproliferative neoplasms (MPN). Although the biological mechanism by which CALR mutations cause MPN has been elucidated, there currently are no clonally selective therapies for CALR-mutant MPN. To identify unique genetic dependencies in CALR-mutant MPN, we performed a whole-genome CRISPR knockout depletion screen in mutant CALR-transformed hematopoietic cells. We found that genes in the N-glycosylation pathway (amongst others) were differentially depleted in mutant CALR-transformed cells as compared with control cells. Using a focused pharmacological screen targeting unique vulnerabilities uncovered in the CRISPR screen, we found that chemical inhibition of N-glycosylation impaired the growth of mutant CALR-transformed cells in vitro. We treated Calr-mutant knockin mice with the N-glycosylation inhibitor, 2-deoxy-glucose (2-DG), and found a preferential sensitivity of Calr-mutant cells to 2-DG as compared to wild-type cells, and a normalization of key MPN disease features. These findings advance the development of clonally selective treatments for CALR-mutant MPN.