Homo sapiens
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ABSTRACT:
PROVIDER: PRJNA253626 | ENA |
REPOSITORIES: ENA
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Project description:Myelodysplastic syndromes (MDS) are a group of clonal hematological disorders characterized by ineffective hematopoiesis with morphological evidence of marrow cell dysplasia resulting in peripheral blood cytopenia. Microarray technology has permitted a refined high-throughput mapping of the transcriptional activity in the human genome. Noncoding-RNAs (ncRNAs) transcribed from intronic regions of genes are involved in a number of processes related to post-transcriptional control of gene expression, and in the regulation of exon-skipping and intron retention. Characterization of ncRNAs in progenitor cells and stromal cells of MDS patients could be strategic for understanding gene expression regulation in this disease. In this study, gene expression profiles of CD34+ and stromal cells of MDS patients with refractory anemia with ringed sideroblasts (RARS) subgroup were compared those of healthy individuals, using 44k combined intron-exon oligoarrays, which included probes for protein-coding genes, for sense and antisense strands of totally intronic noncoding (TIN) and for partially intronic noncoding (PIN) RNAs. In CD34+ cells of MDS-RARS patients, 217 genes were significantly differentially expressed (q-value < 0.01) in comparison to healthy individuals, of which 68 (31%) were noncoding transcripts. In stromal cells of MDS-RARS, 13 genes were significantly differentially expressed (q-value < 0.05) in comparison to healthy individuals, of which 4 (30%) were noncoding transcripts. These results demonstrated, for the first time, in CD34+ cells and stromal cells the differential ncRNA expression profile between MDS-RARS and healthy individuals, suggesting that ncRNAs may play an important role during the development of myelodysplastic syndromes. Bone marrow (BM) CD34+ cell samples were collected from 4 healthy subjects and from 4 MDS patients. Stromal samples were collected from 4 healthy subjects and 3 MDS patients. All patients were diagnosed as RARS according to the French-American-British (FAB) classification and did not present chromosomal abnormalities; they received no growth factors or any further MDS treatment.
2010-06-22 | E-GEOD-18911 | biostudies-arrayexpress
Project description:An increasing body of work reveals aberrant hypermethylation of genes occurring in and potentially contributing to the pathogenesis of myeloid malignancies. Several of these diseases, such as myelodysplastic syndromes (MDS), are responsive to DNA methyltransferase inhibitors. In order to determine the extent of promoter hypermethylation in such tumors we compared the distribution of DNA methylation of 14,000 promoters in MDS and secondary AML patients enrolled in a phase I trial of 5-azacytidine and the histone deacetylase inhibitor entinostat against de novo AML patients and normal CD34+ bone marrow cells. The MDS and secondary AML patients displayed more extensive aberrant DNA methylation involving thousands of genes than did the normal CD34+ bone marrow cells or de novo AML blasts. Aberrant methylation in MDS and secondary AML tended to affect particular chromosomal regions, occurred more frequently in Alu poor genes, and included prominent involvement of genes involved in the WNT and MAPK signaling pathways. DNA methylation was also measured at days 15 and 29 after the first treatment cycle. DNA methylation was reversed at day 15 in a uniform manner throughout the genome, and this effect persisted through day 29, even without continuous administration of the study drugs. Keywords: DNA methylation profiling Direct comparison of DNA methylation in bone marrow samples from patients with Myelodysplastic syndrome or secondary Acute Myeloid Leukemia (AML) at baseline and after in vivo treatment with 5-azacytidine + etinostat. A comparison to de novo normal karyotype AML was also performed. Two control groups were included: one consisting of 8 CD34+ bone marrow samples from healthy donors and a second one consisting of matched CD34+ and CD34- fractions from the bone marrows of 4 healthy donors.
2010-05-15 | E-GEOD-17328 | biostudies-arrayexpress
Project description:The splicing factor SF3B1 is the most commonly mutated gene in the myelodysplastic syndromes (MDS), particularly in patients with refractory anemia with ring sideroblasts (RARS). MDS is a disorder of the hematopoietic stem cell and we thus studied the transcriptome of CD34+ cells from MDS patients with SF3B1 mutations using RNA-sequencing. Genes significantly differentially expressed at the transcript and/or exon level in SF3B1 mutant compared to wildtype cases include genes involved in MDS pathogenesis (ASXL1, CBL), iron homeostasis and mitochondrial metabolism (ALAS2, ABCB7, SLC25A37) and RNA splicing/processing (PRPF8, HNRNPD). Many genes regulated by a DNA damage-induced BRCA1-BCLAF1-SF3B1 protein complex showed differential expression/splicing in SF3B1 mutant cases. Our data indicate that SF3B1 plays a critical role in MDS by affecting the expression and splicing of genes involved in specific cellular processes/pathways, many of which are relevant to the known RARS pathophysiology, suggesting a causal link. RNA-Seq was performed to compare the transcriptome of bone marrow CD34+ cells from eight MDS patients with SF3B1 mutation, four MDS patients with no known splicing mutation and five healthy controls.
2014-11-22 | E-GEOD-63569 | biostudies-arrayexpress
Project description:In this study, we assessed the effects of lysyl oxidase (LOX/LOXL) inhibition on the composition of extracellular matrix (ECM) produced by in vitro expanded bone marrow derived mesenchymal stromal cells (MSCs) of n=3 patients with myelodysplastic syndromes (MDS) and myeloproliferative neoplasms (MPN).
2023-02-17 | PXD031217 | Pride
Project description:Control of oxidative stress in the bone marrow (BM) is key for maintaining the balance between self-renewal, proliferation, and differentiation of hematopoietic cells. Breakdown of this regulation can lead to diseases characterized by BM failure such as the myelodysplastic syndromes (MDS). To better understand the role of oxidative stress in MDS development, we compared protein carbonylation as an oxidative stress marker in BM of patients with MDS and control subjects, and also patients with MDS under treatment with the iron chelator deferasirox.
2019-10-30 | PXD013609 | Pride
Project description:In order to gain insight into the molecular pathogenesis of the myelodysplastic syndromes (MDS), we performed global gene expression profiling and pathway analysis on the hematopoietic stem cells (HSC) of 183 MDS patients as compared with the HSC of 17 healthy controls. The most significantly deregulated pathways in MDS include interferon signaling, thrombopoietin signaling and the Wnt pathway. Among the most significantly deregulated gene pathways in early MDS are immunodeficiency, apoptosis and chemokine signaling, whereas advanced MDS is characterized by deregulation of DNA damage response and checkpoint pathways. We have identified distinct gene expression profiles and deregulated gene pathways in patients with del(5q), trisomy 8 or â??7/del(7q). Patients with trisomy 8 are characterized by deregulation of pathways involved in the immune response, patients with â??7/del(7q) by pathways involved in cell survival, whilst patients with del(5q) show deregulation of integrin signaling and cell cycle regulation pathways. This is the first study to determine deregulated gene pathways and ontology groups in the HSC of a large group of MDS patients. The deregulated pathways identified are likely to be critical to the MDS HSC phenotype and give new insights into the molecular pathogenesis of this disorder thereby providing new targets for therapeutic intervention. 183 patients with MDS patients and 17 healthy controls were included in the study. Bone marrow samples were obtained and CD34+ cells isolated from MDS patients and healthy controls. Samples were hybridized to Affymetrix GeneChip Human Genome U133 Plus 2.0 arrays
2010-03-24 | E-GEOD-19429 | biostudies-arrayexpress
Project description:The marrow microenvironment contributes to the pathogenesis of ineffective hematopoiesis in Myelodysplastic Syndromes (MDS). Since mutations and cytogenetic alterations are generally not present in marrow stromal cells, we hypothesized that epigenetic alterations may be responsible for altered stroma functionin MDS. Global DNA methylation of MDS marrow-derived stroma was analyzed by HELP assay and compared to healthy controls. MDS stroma showed aberrant hypermethylation that preferentially occurred outside of CpG islands and involved important signaling pathways.Comparison with stroma derived from 5-Azacytidine (5-Aza) treated MDS patients revealed abrogation of aberrant methylation in treated samples. Integrative expression analysis revealed that the WNT pathway was epigenetically dysregulated in MDS stroma, and the WNT antagonists FRZB and SFRP1 were aberrantly hypermethylated and underexpressed. These epigenetic changes were validated ina co-culture model of stroma and leukemic cells and in an independent set of MDS samples. Importantly, 5-Aza treatment of MDS stroma enhanced hematopoietic activity and erythroid differentiationfrom co-cultured healthy CD34+ cells. These results reveal widespread aberrant epigenetic changes in the MDS marrow microenvironment and demonstrate that DNA methyl transferase inhibitors alter the epigenomic profiles of stromal cells, potentiallycontributing to theirtherapeutic efficacy. The study population consisted of 6 MDS patients and 3 healthy controls. Individual HpaII restriction digest profiles were compared to an internal MspI digest control, to yield differentially methylated fragments for every sample.
2015-05-20 | E-GEOD-60233 | biostudies-arrayexpress
Project description:Myelodysplastic syndromes (MDS) are a heterogenous group of hematopoietic stem cell disorders characterized by dysplastic blood cell formation and peripheral blood cytopenias. Up to 30% of patients with MDS will progress to a highly chemotherapy-resistant secondary acute myeloid leukemia (sAML). We identified mutations in U2AF1 in MDS patients and patients with U2AF1 mutations are at an increased risk of developing sAML. We identified mutations in U2AF1 in patients with MDS and hypothesized that U2AF1 mutations may represent a novel mechanism that could alter gene expression in MDS. To elucidate gene expression changes associated with U2AF1 mutations, we analyzed the global mRNA expression profile obtained from bone marrow CD34+ cells purified from 5 MDS patients with a U2AF1 mutation, 10 MDS patients without a mutation, and 4 normal donors.
2011-11-23 | E-GEOD-30195 | biostudies-arrayexpress
Project description:SF3B1 mutations, which occur in 20% of patients with myelodysplastic syndromes (MDS), are the hallmarks of a specific MDS subtype, MDS with ringed sideroblasts (MDS-RS), which is characterized by the accumulation of erythroid precursors in the bone marrow.
2022-07-30 | GSE188367 | GEO
Project description:A dosage-dependent role for tumor suppressor genes in the initiation of myeloid malignancies remains controversial. Here we show that MYBL2 is expressed at sharply reduced levels in CD34+ cells from most patients with myelodysplastic syndrome (MDS; 65%; n=26). In a murine competitive reconstitution model, Mybl2 knockdown by RNAi to 20-30% of normal levels in multipotent hematopoietic progenitors led to clonal dominance by these M-bM-^@M-^\sub-haploinsufficientM-bM-^@M-^] cells, affecting all blood cell lineages. By 6 months post-transplantation, the reconstituted mice had developed a myeloproliferative/myelodysplastic disorder originating from the cells with aberrantly reduced Mybl2 expression. Thus, downregulation of MYBL2 activity to levels below those predicted by classical haploinsufficiency drives the clonal expansion of hematopoietic progenitors in a large fraction of human MDS cases. Total RNA was prepared from CD34+ bone marrow cells obtained from MDS patients or healthy controls.
2013-09-15 | E-GEOD-43399 | biostudies-arrayexpress