Project description:The 8p11 myeloproliferative syndrome (EMS), also referred to as the stem cell leukemia/lymphoma syndrome, is a chronic myeloproliferative disorder that rapidly progresses into an acute leukemia. Molecularly, EMS is characterized by fusion of various partner genes to the FGFR1 gene, resulting in constitutive activation of the tyrosine kinase activity within FGFR1. The two most common fusion genes in human EMS are ZMYM2/FGFR1 (previously known as ZNF198/FGFR1) and BCR/FGFR1. To study the transcriptional programs becoming deregulated by the FGFR1 fusion genes, global gene expression analysis on human CD34+ cord blood cells expressing either of the fusion oncogenes ZMYM2/FGFR1 and BCR/FGFR1 was performed. As a reference gene we also included the more studied BCR/ABL1 fusion oncogene associated with chronic myeloid leukemia. We found that the 3 different fusion oncogenes had in common the upregulation of several genes involved in the JAK/STAT signalling pathway and also other sets of genes. However, the gene expression profiles were not identical, suggesting that both the tyrosine kinase containing gene and the partner gene would affect the transcription of downstream target genes. Bicistronic retroviral murine stem cell virus (MSCV) vectors expressing ZMYM2/FGFR1, BCR/FGFR1or P210 BCR/ABL1 and GFP were used. The MIG control vector expressed GFP only. Two days post transfection of human CD34+ umbilical cord blood cells, GFP-sorted cells were collected in three biological replicates and RNA was isolated immediately. In total, 12 samples were hybridized and scanned.
Project description:The 8p11 myeloproliferative syndrome (EMS), also referred to as the stem cell leukemia/lymphoma syndrome, is a chronic myeloproliferative disorder that rapidly progresses into an acute leukemia. Molecularly, EMS is characterized by fusion of various partner genes to the FGFR1 gene, resulting in constitutive activation of the tyrosine kinase activity within FGFR1. The two most common fusion genes in human EMS are ZMYM2/FGFR1 (previously known as ZNF198/FGFR1) and BCR/FGFR1. To study the transcriptional programs becoming deregulated by the FGFR1 fusion genes, global gene expression analysis on human CD34+ cord blood cells expressing either of the fusion oncogenes ZMYM2/FGFR1 and BCR/FGFR1 was performed. As a reference gene we also included the more studied BCR/ABL1 fusion oncogene associated with chronic myeloid leukemia. We found that the 3 different fusion oncogenes had in common the upregulation of several genes involved in the JAK/STAT signalling pathway and also other sets of genes. However, the gene expression profiles were not identical, suggesting that both the tyrosine kinase containing gene and the partner gene would affect the transcription of downstream target genes.
Project description:Expression of P190 and P210 BCR/ABL1 in normal human CD34(+) cells induces similar gene expression profiles and results in a STAT5-dependent expansion of the erythroid lineage The P190 and P210 BCR/ABL1 fusion genes are mainly associated with different types of hematologic malignancies, but it is presently unclear whether they are functionally different following expression in primitive human hematopoietic cells. We investigated and systematically compared the effects of retroviral P190 BCR/ABL1 and P210 BCR/ABL1 expression on cell proliferation, differentiation, and global gene expression in human CD34(+) cells from cord blood. Expression of either P190 BCR/ABL1 or P210 BCR/ABL1 resulted in expansion of erythroid cells and stimulated erythropoietin-independent burst-forming unit-erythroid colony formation. By using a lentiviral anti-signal transducer and activator of transcription 5 (STAT5) short-hairpin RNA, we found that both P190 BCR/ABL1- and P210 BCR/ABL1-induced erythroid cell expansion were STAT5-dependent. Under in vitro conditions favoring B-cell differentiation, neither P190 nor P210 BCR/ABL1-expressing cells formed detectable levels of CD19-positive cells. Gene expression profiling revealed that P190 BCR/ABL1 and P210 BCR/ABL1 induced almost identical gene expression profiles, and we identified a common set of 222 differentially expressed genes. Our data suggest that the early cellular and transcriptional effects of P190 BCR/ABL1 and P210 BCR/ABL1 expression are very similar when they are expressed in the same human progenitor cell population, and that STAT5 is an important regulator of BCR/ABL1-induced erythroid cell expansion. Keywords: global gene expression profiling, BCR/ABL1, CD34+ cord blood cells, CML, Ph+ ALL
Project description:Analysis of lineage depleted human cord blood cells sequentially transduced with retro- (BCR-ABL1) and lentiviral (Ik6) vectors and the corresponding controls. Results provide important informations on the collaboration of BCR-ABL1 and Ik6 in human hematopoietic cells. Double-transduced lineage depleted human cord blood cells were puirifed according to GFP and LNGFR expression. RNA was extracted from purified cells.
Project description:Analysis of lineage depleted human cord blood cells sequentially transduced with retro- (BCR-ABL1) and lentiviral (Ik6) vectors and the corresponding controls. Results provide important informations on the collaboration of BCR-ABL1 and Ik6 in human hematopoietic cells.
Project description:BACKGROUND: BCR-ABL1+ chronic myeloid leukemia (CML) is characterized by abnormal production of leukemic stem (LSC) and progenitor cells and their spread from the bone marrow into the blood resulting in extramedullary myeloproliferation. So far, little is known about specific markers and functions of LSC in CML. METHODS: We examined the phenotype and function of CD34+/CD38─/Lin─ CML LSC by a multi-parameter screen approach employing antibody-phenotyping, mRNA expression profiling, and functional studies, including LSC repopulation experiments in irradiated NOD-SCID-IL-2Rgamma-/- (NSG) mice, followed by marker-validation using diverse control-cohorts and follow-up samples of CML patients treated with imatinib. RESULTS: Of all LSC markers examined, dipeptidylpeptidase IV (DPPIV=CD26) was identified as specific and functionally relevant surface marker-enzyme on CD34+/CD38─ CML LSC. CD26 was not detected on normal CD34+/CD38─ stem cells or LSC in other hematopoietic malignancies. The percentage of CD26+ CML LSC decreased to undetectable levels during successful treatment with imatinib in all patients (p<0.001). Whereas the sorted CD26─ stem cells obtained from CML patients engrafted irradiated NSG mice with multilineage BCR-ABL1-negative hematopoiesis, CD26+ LSC engrafted NSG mice with BCR-ABL1+ cells. Functionally, CD26 was identified as target-enzyme disrupting the SDF-1alpha-CXCR4-axis by cleaving SDF-1alpha a chemotaxin for CXCR4+ stem cells. Whereas CD26 was found to inhibit SDF-1alpha-induced migration, CD26-targeting gliptins reverted this effect and blocked the mobilization of CML LSC in a stroma co-culture assay. CONCLUSIONS: CD26 is a robust biomarker of LSC and a useful tool for their quantification and isolation in patients with BCR/ABL1+ CML. Moreover, CD26 expression may explain the extramedullary spread of LSC in CML. To define specific mRNA expression patterns and to identify specific LSC markers in CML LSC, gene array analyses were performed. RNA was isolated from sorted CD34+/CD45+/CD38─ CML LSC, CD34+/CD45+/CD38+ CML progenitor cells, CML MNC, sorted CD34+/CD38─ cord blood (CB) SC, CB-derived CD34+/CD38+ progenitor cells, and CB MNC. Total RNA was extracted from sorted cells using RNeasy Micro-Kit (Qiagen) and used (100 ng total RNA) for Gene Chip analyses. Preparation of terminal-labeled cRNA, hybridization to genome-wide human PrimeView GeneChips (Affymetrix, Santa Clara, CA, USA) and scanning of arrays were carried out according to the manufacturer's protocols (https://www.affymetrix.com). Robust Multichip Average (RMA) signal extraction and normalization were performed according to http://www.bioconductor.org/ as described.18 Differences in mRNA expression levels (from multiple paired samples) were calculated as mRNA ratio of i) CML LSC versus CB SC, ii) CML LSC versus CD34+/CD38+ CML progenitors, and normal cord blood SC versus cord blood progenitors. To calculate differential gene expression between individual sample groups where appropriate, we performed a statistical comparison using the LIMMA package as described previously. Briefly, LIMMA estimates the fold change between predefined sample groups by fitting a linear model and using an empirical Bayes method to moderate the standard errors of the estimated log-fold changes for each probe set.
Project description:The ZMYM2-FGFR1 (formerly known as ZNF198-FGFR1) fusion kinase induces stem cell leukemia-lymphoma syndrome (SCLL), a hematological malignancy characterized by rapid transformation to acute myeloid leukemia and T-lymphoblastic lymphoma. We previously developed a mouse model of ZMYM2-FGFR1 (Ren et al. 2009, Blood). To further investigate mechanisms of oncogenesis and progression, we undertook a global gene expression analysis of leukemic T-cells from the animal model compared with Thy1+DP+ (CD4+CD8+) cells isolated from normal Balb/c thymuses, as well as lukemic stem cells (LSK, GFP+Lin-Sca-1+c-kit+ cells) sorted from the leukemic mice versus hematopoietic stem cells (HSC, Lin-Sca-1+c-kit+ cells) sorted from normal BALB/c bone marrow cells. We found high expressions of Notch1 and its downstream target genes in T-cell lymphomas that arise in a murine model of ZMYM2-FGFR1 SCLL. Our functional studies demonstrate the importance of Notch signaling in the etiology of SCLL and suggest that targeting this pathway could provide a novel strategy for molecular therapies to treat SCLL patients.