Project description:Early, low risk IPSS (International Prognostic Scoring System) myelodysplasia (MDS) is a heterogeneous disorder where the molecular and cellular haematopoietic defects are poorly understood. To gain insight into this condition, we analyzed gene expression profiles of marrow CD34+ progenitor cells from normal karyotype, low blast count MDS patients, age-matched controls and patients with non-MDS anaemia. The aim of the study was to further understanding of the cellular defect in MDS and to identify biomarkers of disease Experiment Overall Design: Bone marrow (BM) CD34 cells were purified from patients with MDS, non-MDS anemia and from normal donors. Total RNA was extracted from Tri-reagent and quality verified on by capillary electrophoresis (Agilent). RNA was amplified by the Affymetrix small sample protocol. cRNA was hybridised to Affymetrix U133A chips under standard conditions. Initial data was analysed in MAS 5.0
Project description:CD34 positive cells of bone marrow samples from normal and MDS samples were cultured ex vivo into erythroid conditions. We used microarrays to detail the gene expression programm of erythroid cells between normal and pathological (MDS) samples Mononuclear cells from bone marrow samples were selected on the expression of the CD34 membran marker. Then, they were cultured ex vivo during 14 days and total RNA samples were analyzed at day 7, 10 and/or 14 then compared between normal and MDS samples.
Project description:CD34 positive cells of bone marrow samples from normal and MDS samples were cultured ex vivo into erythroid conditions. We used microarrays to detail the gene expression programm of erythroid cells between normal and pathological (MDS) samples
Project description:Transcription profiling by array of human CD34+ cells from bone marrow of patients with mucosa-associated lymphoid tissue (MLAT) lymphoma and control CD34+ cells from healthy individuals
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.
Project description:Early, low risk IPSS (International Prognostic Scoring System) myelodysplasia (MDS) is a heterogeneous disorder where the molecular and cellular haematopoietic defects are poorly understood. To gain insight into this condition, we analyzed gene expression profiles of marrow CD34+ progenitor cells from normal karyotype, low blast count MDS patients, age-matched controls and patients with non-MDS anaemia. The aim of the study was to further understanding of the cellular defect in MDS and to identify biomarkers of disease Keywords: Disease v normal
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.
Project description:RNA-seq of bone marrow CD34+ cells from myelodysplastic syndrome patients with and without SF3B1 mutation and from healthy controls
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.