Integrative genomics identifies the molecular basis of resistance to Azacytidine therapy in Myelodysplastic Syndromes
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE76203 | GEO | 2017/07/20
SECONDARY ACCESSION(S): PRJNA306622
REPOSITORIES: GEO
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Project description:5-azacytidine (AZA) is widely used for treatment of myelodysplastic syndromes (MDS). However, identifying predictive factors for response to AZA remains challenging. The aim in present study was to identify the genes which are susceptible to AZA in MDS and investigate the possibility of the gene for predictor for response to AZA therapy. To identify AZA-susceptible genes, we compared the gene expression changes by AZA in MDS-L cells (AZA-sensitive) with those in MDS-L/CDA cells (AZA-resistant) in culture. Of 438 AZA-susceptible genes, we searched the genes which are hypermethylated in MDS patients as compared to healthy controls by analyzing public dataset GSE152710, and found ALOX12 gene. Analysis of public dataset GSE145733 and GSE58831 revealed that ALOX12 expression was suppressed in MDS classes with excess blasts but not in other classes, and were negatively and positively correlated with bone marrow blast counts and survival, respectively, in MDS patients. Analysis of public dataset GSE152710 revealed that the methylation level of ALOX12 gene was decreased in MDS patients with complete remission but not in those with partial response and progression disease after AZA therapy. Our retrospective clinical study in which nine AZA-treated patients were enrolled suggested that ALOX12 expression was increased in patients with favorable response, while decreased in patient with poor response after AZA therapy. In conclusion, ALOX12 gene could be tumor suppressive and promising marker for predicting the response to AZA therapy in MDS.
2023-05-31 | GSE233764 | GEO
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:Malignancies can become reliant on glutamine as an alternative energy source and as a facilitator of aberrant DNA methylation, thus implicating glutaminase (GLS) as a potential therapeutic target. We demonstrate preclinical synergy of telaglenastat (CB-839), a selective GLS inhibitor, when combined with azacytidine (AZA), in vitro and in vivo, followed by a phase Ib/II study of the combination in patients with advanced MDS. Treatment with telaglenastat/AZA led to an ORR of 70% with CR/mCRs in 53% patients and a median overall survival of 11.6 months. scRNAseq and flow cytometry demonstrated a myeloid differentiation program at the stem cell level in clinical responders. Expression of non-canonical glutamine transporter, SLC38A1, was found to be overexpressed in MDS stem cells; was associated with clinical responses to telaglenastat/AZA and predictive of worse prognosis in a large MDS cohort. These data demonstrate the safety and efficacy of a combined metabolic and epigenetic approach in MDS.
2024-02-12 | GSE225352 | GEO
Project description:Mesenchymal stromal cells (MSC) are crucial components of the bone marrow (BM) microenvironment essential for regulating self-renewal, survival and differentiation of hematopoietic stem/progenitor cells (HSPC) in the stem cell niche. MSC are functionally and phenotypically altered in myelodysplastic syndromes (MDS), contributing to disease progression. MDS MSC do not harbor recurrent genetic alterations but have been shown to exhibit an altered methylome compared to MSC from healthy controls. We examined growth, differentiation and HSPC-supporting capacity of ex vivo expanded MSC from MDS patients in comparison to age-matched healthy controls after direct treatment in vitro with the hypomethylating agent azacitidine (AZA). We show that AZA exerts a direct effect on MSC by modulating their differentiation potential. Osteogenesis was significantly boosted in healthy MSC while adipogenesis was inhibited in both healthy and MDS MSC. In co-culture experiments, both AZA treated MDS MSC and healthy MSC exhibited enhanced support of non-clonal HSPC which was associated with increased cell cycle induction. Conversely, clonal MDS HSPC were inhibited by contact with AZA treated MSC. RNA-sequencing analyses of stromal cells revealed changes in pathways essential for HSPC support as well as in immune regulatory pathways. In sum, our data demonstrate that AZA treatment of stromal cells leads to upregulation of HSPC-supportive genes and cell cycle induction in co-cultured healthy HSPC, resulting in a proliferative advantage over clonal HSPC. Thus, restoration of functional hematopoiesis by AZA may be driven by activated stromal support factors in MSC providing cell cycle cues to healthy HSPC.
2018-12-19 | GSE112461 | GEO
Project description:NHLBI TOPMed: Genomics of Myelodysplastic Syndromes (MDS)
| PRJNA703724 | ENA
Project description:NHLBI TOPMed: Genomics of Myelodysplastic Syndromes (MDS)
| PRJNA703723 | ENA
Project description:Mutations in the TET2 gene are frequent in myeloid disease, although their biological and prognostic significance remains unclear. We analyzed 355 patients with myelodysplastic syndromes using ‘Next-Generation’ sequencing (NGS) for TET2 aberrations; 91 of whom were also subjected to SNP6 array karyotyping. Seventy-one TET2 mutations, with a relative mutation abundance (RMA) ≥10%, were identified in 39 of 320 (12%) MDS and 16 of 35 (46%) CMML patients (p<0.001). Interestingly, 4 patients had multiple mutations likely to exist as independent clones or on alternate alleles, suggestive of clonal evolution. ‘Deeper’ sequencing of 96 patient samples identified 4 additional mutations (RMA 3%-6.3%). Importantly, TET2 mutant clones were also found in T cells in addition to CD34+ and total bone-marrow cells (23.5%, 38.5% and 43% RMA respectively). Only 20% of the TET2-mutated patients showed loss of heterozygosity at the TET2 locus. There was no difference in the frequency of genome-wide aberrations, TET2 expression or the JAK2V617F 46/1 haplotype between TET2-mutated and non-mutated patients. There was no significant prognostic association between TET2 mutations and WHO subtypes, IPSS score, cytogenetic status, or transformation to AML. On multivariate analysis, age (>50yrs) was associated with a higher incidence of TET2 mutation (p=0.02). Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from bone marrow or peripheral blood samples. Copy number and acquired UPD analysis of Affymetrix SNP 6.0 arrays was performed for 91 cases with Myelodysplastic syndromes.
2010-07-30 | E-GEOD-23300 | 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: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.
2011-11-23 | GSE30195 | GEO
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