Homo sapiens
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PROVIDER: PRJNA296056 | ENA |
REPOSITORIES: ENA
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Project description:The diagnosis of myelodysplastic syndromes (MDS) remains problematic due to the subjective nature of morphological assessment. The reported high frequency of somatic mutations and increased structural variants by array-based cytogenetics have provided potential objective markers of disease however this has been complicated by reports of similar abnormalities in the healthy population. We aimed to identify distinguishing features between those with early MDS and reported healthy individuals by characterising 69 patients who, following a non-diagnostic marrow, developed progressive dysplasia or acute myeloid leukaemia (AML). Targeted sequencing and array based cytogenetics identified a driver mutation and/or structural variant in 91% (63/69) of pre-diagnostic samples with the mutational spectrum mirroring that in the MDS population. When compared with the reported healthy population the mutations detected had significantly greater median variant allele fraction (40% vs 9-10%) and occurred more commonly with additional mutations (≥2 mutations 64% vs. 8%). Furthermore mutational analysis identified a high-risk group of patients with shorter time to disease progression and poorer overall survival. The mutational features in our cohort are distinct from those seen in the healthy population and, even in the absence of definitive disease, can predict outcome. Early detection may allow consideration of intervention in poor risk patients. We performed array based cytogenetics using HumanCytoSNP-12 (Illumina) on 69 patients diagnosed with acute myeloid leukaemia or myelodysplastic syndrome who had a previously non-diagnostic sample. SNP array analysis was performed on all diagnostic samples. In those with a documented abnormality, SNP-A was performed on the corresponding pre-diagnostic sample (n=32).
2015-09-17 | E-GEOD-73074 | biostudies-arrayexpress
Project description:The diagnosis of myelodysplastic syndromes (MDS) remains problematic due to the subjective nature of morphological assessment. The reported high frequency of somatic mutations and increased structural variants by array-based cytogenetics have provided potential objective markers of disease however this has been complicated by reports of similar abnormalities in the healthy population. We aimed to identify distinguishing features between those with early MDS and reported healthy individuals by characterising 69 patients who, following a non-diagnostic marrow, developed progressive dysplasia or acute myeloid leukaemia (AML). Targeted sequencing and array based cytogenetics identified a driver mutation and/or structural variant in 91% (63/69) of pre-diagnostic samples with the mutational spectrum mirroring that in the MDS population. When compared with the reported healthy population the mutations detected had significantly greater median variant allele fraction (40% vs 9-10%) and occurred more commonly with additional mutations (≥2 mutations 64% vs. 8%). Furthermore mutational analysis identified a high-risk group of patients with shorter time to disease progression and poorer overall survival. The mutational features in our cohort are distinct from those seen in the healthy population and, even in the absence of definitive disease, can predict outcome. Early detection may allow consideration of intervention in poor risk patients.
2015-09-17 | GSE73074 | GEO
Project description:Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal disorders characterized variably by the presence of peripheral cytopenias, bone marrow hypercellularity and dysplastic changes in the bone marrow. While MDS patients have an increased risk of progression to acute myeloid leukemia (AML), most MDS patients actually succumb to progressive bone marrow failure. Amongst patients classified as low-risk MDS, different clinical evolutions have been observed, with some patients remaining relatively stable for long periods of time (herein, stable MDS), while others show more progressive disease, with worsening cytopenias, and often increased transfusion requirements (herein, progressive MDS). Current risk stratification strategies fail to distinguish these two groups at diagnosis. We report here that these distinct behaviors are encoded at the epigenetic level and that examining DNA methylation profiles of low-risk MDS patients captures underlying differences between the two different groups. In this study, we identified 356 differentially methylated regions (DMRs) between stable and progressive low-risk MDS at the time of diagnosis. The number of DMRs was almost doubled at the time of progression (681 follow-up DMRs), and this was accompanied by an increase in the local variability at specific methylation regions, and an increase in heterogeneity over time. These findings reveal previously unrecognized epigenetic heterogeneity in low-risk MDS patients and opens the possibility for using epigenetic differences to help improve risk-stratification at diagnosis.
2020-04-14 | GSE108247 | GEO
Project description:The progressive mechanism of myelodysplastic syndrome (MDS) remains unknown. We report that ROBO1 and ROBO2 are identified as novel progression-related somatic mutations using whole-exome and targeted sequencing in six of 16 (37.5%) paired MDS patients undergoing disease progression. To investigated the effect of ROBO1 or ROBO2 on ROBO1/2 CN number and LOH, we employed a Cytosan 750K chip to analyze the copy-number variations (CNVs) and loss of heterogeneity (LOH) in MDS patients with ROBO1&2 mutations. Copy number and LOH analysis of Affymetrix CytoScan 750K array was performed for 14 MDS patients with ROBO1 or ROBO2 mutations
2015-09-15 | E-GEOD-73005 | biostudies-arrayexpress
Project description:Genome-wide expression and methylation profiling identifies novel targets with aberrant hypermethylation and reduced expression in low-risk myelodysplastic syndromes (MDSs). Gene expression profiling signatures may be used to classify the subtypes of Myelodysplastic syndrome (MDS) patients. However, there are few reports on the global methylation status in MDS. The integration of genome-wide epigenetic regulatory marks with gene expression levels would provide additional information regarding the biological differences between MDS and healthy controls. Gene expression and methylation status were measured using high-density microarrays. A total of 552 differentially methylated CpG loci were identified as being present in low-risk MDS; hypermethylated genes were more frequent than hypomethylated genes. In addition, mRNA expression profiling identified 1005 genes that significantly differed between low-risk MDS and the control group. Integrative analysis of the epigenetic and expression profiles revealed that 66.7% of the hypermethylated genes were underexpressed in low-risk MDS cases. Gene network analysis revealed molecular mechanisms associated with the low-risk MDS group, including altered apoptosis pathways. The two key apoptotic genes BCL2 and ETS1 were identified as silenced genes. In addition, the immune response and micro RNA biogenesis were affected by the hypermethylation and underexpression of IL27RA and DICER1. Our integrative analysis revealed that aberrant epigenetic regulation is a hallmark of low-risk MDS patients and could have a central role in these diseases. Low-risk MDS patients and age-matched controls without haematological malignancies were included in the study. Mononuclear cells were isolated from bone marrow samples of low-risk MDS patients and controls by density gradient (Ficoll). A cohort of 18 patients with low-risk MDS and seven controls were included in a simultaneous integrative study of methylation and expression, while the whole series was used as a control group of expression data.
2012-09-25 | E-GEOD-41130 | biostudies-arrayexpress
Project description:Genome-wide expression and methylation profiling identifies novel targets with aberrant hypermethylation and reduced expression in low-risk myelodysplastic syndromes (MDSs). Gene expression profiling signatures may be used to classify the subtypes of Myelodysplastic syndrome (MDS) patients. However, there are few reports on the global methylation status in MDS. The integration of genome-wide epigenetic regulatory marks with gene expression levels would provide additional information regarding the biological differences between MDS and healthy controls. Gene expression and methylation status were measured using high-density microarrays. A total of 552 differentially methylated CpG loci were identified as being present in low-risk MDS; hypermethylated genes were more frequent than hypomethylated genes. In addition, mRNA expression profiling identified 1005 genes that significantly differed between low-risk MDS and the control group. Integrative analysis of the epigenetic and expression profiles revealed that 66.7% of the hypermethylated genes were underexpressed in low-risk MDS cases. Gene network analysis revealed molecular mechanisms associated with the low-risk MDS group, including altered apoptosis pathways. The two key apoptotic genes BCL2 and ETS1 were identified as silenced genes. In addition, the immune response and micro RNA biogenesis were affected by the hypermethylation and underexpression of IL27RA and DICER1. Our integrative analysis revealed that aberrant epigenetic regulation is a hallmark of low-risk MDS patients and could have a central role in these diseases. Low-risk MDS patients and age-matched controls without haematological malignancies were included in the study. Mononuclear cells were isolated from bone marrow samples of low-risk MDS patients and controls by density gradient (Ficoll). A cohort of 18 patients with low-risk MDS and seven controls were included in a simultaneous integrative study of methylation (using Methylated CpG Island Amplification and Microarrays, MCAM) and expression (using Affymetrix microarrays HG-U133 Plus 2), while the whole series was used as a control group of expression data.
2012-09-28 | E-GEOD-41215 | biostudies-arrayexpress
Project description:Therapy-related myelodysplasia or acute myeloid leukemia (t-MDS/AML) is a lethal complication of cancer treatment. Although t-MDS/AML development is associated with known genotoxic exposures, its pathogenesis is not well understood and methods to predict risk of development of t-MDS/AML in individual cancer survivors are not available. We performed microarray analysis of gene expression in samples from patients who developed t-MDS/AML after autologous hematopoietic cell transplantation (aHCT) for Hodgkin lymphoma (HL) or non-Hodgkin lymphoma (NHL) and controls that did not develop t-MDS/AML after aHCT. CD34+ progenitor cells from peripheral blood stem cell (PBSC) samples obtained pre-aHCT from t-MDS/AML cases and matched controls, and bone marrow (BM) samples obtained at time of development of t-MDS/AML, were studied. Significant differences in gene expression were seen in PBSC obtained pre-aHCT from patients who subsequently developed t-MDS/AML compared to controls. Genetic alterations in pre-aHCT samples were related to mitochondrial function, protein synthesis, metabolic regulation and hematopoietic regulation. Progression to overt t-MDS/AML was associated with additional alterations in DNA repair and DNA-damage checkpoint genes. Altered gene expression in PBSC samples were validated in an independent group of patients. An optimal 63-gene PBSC classifier derived from the training set accurately distinguished patients who did or did not develop t-MDS/AML in the independent test set. These results indicate that genetic programs associated with t-MDS/AML are perturbed long before disease onset, and can accurately identify those at risk of developing this complication.
2011-12-12 | GSE23025 | GEO
Project description:Prior studies using DNA microarray platforms have shown alterations of gene expression profiles (GEPs) of marrow cells in myelodysplastic syndromes (MDS). Using the increased sensitivity and accuracy of high-throughput RNA sequencing (RNA-Seq) for detecting and quantifying mRNA transcripts, our study has demonstrated novel significant differences in GEPs between MDS and normal CD34+ marrow cells with 41 genes identified as disease classifiers. Additionally, two main clusters of GEPs distinguished patients based on their major clinical features, particularly between those whose disease remained stable (sMDS) vs patients whose illness transformed to acute myeloid leukemia within 12 months (tMDS). The genes whose expression was associated with disease outcome were involved in functional pathways and biologic processes highly relevant for MDS. Exomic analysis identified MDS-associated pathogenic mutations in virtually all patients tested. MDS subgroups with spliceosome mutations demonstrated distinct differential isoform usage and expression and consequent dysregulation of distinct biological functions. This combination of clinical, transcriptomic and exomic findings provides valuable molecular insights into the mechanisms underlying MDS and its progression to a more aggressive stage and also facilitates prognostic characterization of MDS patients.
2018-04-09 | GSE111085 | GEO
Project description:The nucleotide analogue azacitidine (AZA) interferes with RNA and DNA metabolism and is currently the best treatment option for a subset of patients with high-risk myelodysplastic syndromes. However, only half of treated patients respond and almost all patients that initially respond eventually relapse. Thus, response-predicting biomarkers and new treatment options are urgently needed to improve the clinical management of these patients. Here, we performed a loss-of-function shRNA screen in combination with AZA treatment in a MDS-derived AML cell line to identify chromatin regulators affecting drug response. We identified the histone acetyl transferase and transcriptional co-activator CBP as a major regulator of AZA sensitivity. Compounds inhibiting the enzymatic activity of CBP synergistically reduced viability of MDS-derived AML cell lines when combined with AZA. Surprisingly, this affect was specific for the RNA-dependent functions of AZA and not observed with the related compound decitabine that is limited to DNA incorporation. The identification of immediate target genes suggested that the effect of CBP inhibition is mediated by downregulation of genes encoding the translational machinery, which could be confirmed in proteomic analysis of nascent proteins. Furthermore, proteins most affected by CBP inhibition include key drivers of cycle progression. Taken together, our results identify a novel synergistic interaction between CBP inhibitors and specifically AZA that warrants further evaluation for the combinatorial treatment of high-risk MDS patients. Beyond the scope of MDS and AZA, we provide novel insight in the function of clinically promising CBP inhibitors that is related to unexpected interference with the translational machinery.
2021-09-22 | PXD021738 | Pride
Project description:Identification of relevant subgroups in childhood MDS patients by gene expression analysis and gene involve in progression into AML Class comparison between different subgroups of pediatric MDS (class risk, classification subtype)
2012-02-29 | E-GEOD-29326 | biostudies-arrayexpress