REPROGRAMMING IDENTIFIES FUNCTIONALLY DISTINCT STAGES OF CLONAL EVOLUTION IN MYELODYSPLASTIC SYNDROMES
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE129851 | GEO | 2019/04/17
REPOSITORIES: GEO
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Project description:Myelodysplastic syndromes (MDS) are uncommon entities, heterogeneous clinically and cytogenetically. Recently, a new drug, Lenalidomide, has demonstrated to be very effective in patients with MDS and 5q- reaching 70% of hematological responses whereas patients with MDS without 5q- has only 20-30% of hematological responses. The aim of the present study is to determine genetic alteration in this subset of patients, and describe candidate genes related with response or resistance to Lenalidomide. The aim of the present study is to determine genetic alteration in this subset of patients, and describe candidate genes related with response or resistance to Lenalidomide. Copy number analysis of Affymetrix GenomeWide SNP 6.0 arrays was performed for 2 patients with MDS an isolated 5q- by conventional cytogenetics. There are also 2 samples from separated CD3+ lymphocytes, which were used as references for copy number and LOH inference.
2014-10-07 | E-GEOD-59244 | biostudies-arrayexpress
Project description:Myelodysplastic syndromes (MDS) are uncommon entities, heterogeneous clinically and cytogenetically. Recently, a new drug, Lenalidomide, has demonstrated to be very effective in patients with MDS and 5q- reaching 70% of hematological responses whereas patients with MDS without 5q- has only 20-30% of hematological responses. The aim of the present study is to determine genetic alteration in this subset of patients, and describe candidate genes related with response or resistance to Lenalidomide.
2014-10-07 | GSE59244 | GEO
Project description:Despite the high response rates of individuals with myelodysplastic syndrome (MDS) with deletion of chromosome 5q (del(5q)) to treatment with lenalidomide (LEN) and the recent identification of cereblon (CRBN) as the molecular target of LEN, the cellular mechanism by which LEN eliminates MDS clones remains elusive. Here we performed an RNA interference screen to delineate gene regulatory networks that mediate LEN responsiveness in an MDS cell line, MDSL. We identified GPR68, which encodes a G-protein-coupled receptor that has been implicated in calcium metabolism, as the top candidate gene for modulating sensitivity to LEN. LEN induced GPR68 expression via IKAROS family zinc finger 1 (IKZF1), resulting in increased cytosolic calcium levels and activation of a calcium-dependent calpain, CAPN1, which were requisite steps for induction of apoptosis in MDS cells and in acute myeloid leukemia (AML) cells. In contrast, deletion of GPR68 or inhibition of calcium and calpain activation suppressed LEN-induced cytotoxicity. Moreover, expression of calpastatin (CAST), an endogenous CAPN1 inhibitor that is encoded by a gene (CAST) deleted in del(5q) MDS, correlated with LEN responsiveness in patients with del(5q) MDS. Depletion of CAST restored responsiveness of LEN-resistant non-del(5q) MDS cells and AML cells, providing an explanation for the superior responses of patients with del(5q) MDS to LEN treatment. Our study describes a cellular mechanism by which LEN, acting through CRBN and IKZF1, has cytotoxic effects in MDS and AML that depend on a calcium- and calpain-dependent pathway.
2016-06-08 | GSE82235 | GEO
Project description:Myelodysplastic syndromes (MDS) are a group of clonal disorders of hematopoietic stem cells. Mesenchymal stem cells (MSC) are the progenitors of the Bone Marrow (BM) stroma and have been involved in the physiopathology of MDS. The presence of cytogenetic aberrations on MSC from MDS patients is controversial. The aim of the study is to characterize BM derived MSC from patients with MDS using: kinetic studies, immunophenotyping, fluorescent in situ hybridisation (FISH) analysis and genetic changes by array based comparative genomic hybridization (array-CGH). 32 cases of untreated MDS were included in the study. MSC from MDS achieved confluence at a slower rate than donor-MSC, and the antigenic expression of CD105 and CD104 was also lower. Array-CGH studies showed DNA genomic changes that were proved not to be somatic, and gains were more frequent than looses. The results of array-CGH were confirmed by FISH. When an unsupervised hierarchical cluster analysis was performed two clusters were identified: one of them included the 5q- syndrome patients, while the other incorporated the rest of the MDS patients. Our results shows, for the first time, that MSC from MDS display genomic aberrations, assessed by array-CGH and FISH, some of them specially linked to particular MDS subtypes. Keywords: Genomic comparison between mesenchymal cells
2008-08-01 | GSE10822 | GEO
Project description:Myelodysplastic syndromes (MDS) are a group of clonal disorders of hematopoietic stem cells. Mesenchymal stem cells (MSC) are the progenitors of the Bone Marrow (BM) stroma and have been involved in the physiopathology of MDS. The presence of cytogenetic aberrations on MSC from MDS patients is controversial. The aim of the study is to characterize BM derived MSC from patients with MDS using: kinetic studies, immunophenotyping, fluorescent in situ hybridisation (FISH) analysis and genetic changes by array based comparative genomic hybridization (array-CGH). 32 cases of untreated MDS were included in the study. MSC from MDS achieved confluence at a slower rate than donor-MSC, and the antigenic expression of CD105 and CD104 was also lower. Array-CGH studies showed DNA genomic changes that were proved not to be somatic, and gains were more frequent than looses. The results of array-CGH were confirmed by FISH. When an unsupervised hierarchical cluster analysis was performed two clusters were identified: one of them included the 5q- syndrome patients, while the other incorporated the rest of the MDS patients. Our results shows, for the first time, that MSC from MDS display genomic aberrations, assessed by array-CGH and FISH, some of them specially linked to particular MDS subtypes. Keywords: Genomic comparison between mesenchymal cells 32 BM cells from âde novoâ MDS, corresponding to 29 patients, were included in the study. Male/female ratio was 14/15 and median age was 70 years (range 34-89). MDS diagnosis was established by peripheral blood counts and morphology, BM morphology and cytogenetic analyses and classified according to the WHO proposals. 12 Patientsâ characteristics are summarized in table 1. Three patients were included twice in the study: at the diagnosis of one RA (case 2) and two Unclassifiable MDS (cases 29,30), and at the progression into RAEB-2 (cases 16, 20 and 18). None of them had received treatment during this period of time, other than supportive therapy. Normal BM samples were obtained from 15 healthy donors, 8 males and 7 females, with a median age of 57 (range 37-88). Written informed consent was obtained from all patients and donors according to ethical guidelines of our institution. Genomic-wide analysis of DNA copy number changes of MSC from 13 cases was performed using array-CGH. Slides containing 3032 BACs were produced in âCentro de Investigación del Cáncerâ (Salamanca, Spain). The particular BAC and P-1 derived artificial chromosome set used to produce this array is distributed to academic institutions by the Welcome Trust Sanger Institute (Cambridge, United Kingdom) and contains targets spaced at ï» 1 Mb density over full genome, a set of subtelomeric sequences for each chromosome arm, and a few hundred probes selected for their involvement in oncogenesis. The clone content is available in the âCytoviewâ windows of the Sanger Institute mapping database site, Ensembl (http://www.ensembl.org/). According to this database, clones were ordered along the chromosomes. These clones were isolated from their bacterial cultures with the relevant antibiotics and the DNA was extracted with standard protocol Welcome Trust Sanger Institute (Cambridge, UK). 10 ng of DNA (BAC/PAC) was used as a template for three DOP-PC. 22;23 These products were ethanol precipitated and dissolved in distilled water. A minimum of three replicates per clone were printed by Microgrid II (Biorobotics) on each slide (Ultragaps Coated Slides, Corning) using the aqueous dimethylsulfoxide buffer as spotting solution. Briefly, for labelling reactions, 1 μg of nonamplified genomic DNA, test and reference were digested separately with DpnII restriction enzyme (New England Biolabs, Beverly, MA). For microarray hybridization, the digested DNAs were separately labelled using random primers (Bioprimer labelling kit, Invitrogen) and cyanine dye-3-dCTP and cyanine dye-5-dCTP fluorescent dye to paired hybridisation samples (Amersham Biosciences). The incorporated of the label nucleotide was quantified using the Nanodrop spectrophotometer. Labelled test and reference DNAs were mixed equitably, co-precipitated in presence of Cot-1 human DNA (Roche, Indianapolis, IN) with ethanol, washed, and resuspended in hybridization solution (50% Formamide, 10% Dextran sulfate, 2X standard saline citrate, 10 mM Tris pH 7.6, 2.7% sodium dodecyl sulfate and 10 μg/ μl of yeast tRNA). DNA mixtures were hybridized to the arrays in the TECAN HS4800 Pro according to the manufacturerâs recommended protocol. Images and signal intensities were acquired using GenePix4000B (Axon Instruments, Burlingame, CA) dual laser scanner in combination with GenePixPro4.0 (Axon Instruments) imaging software. Image and Data analysis. Spot intensities measured by the GenePix Pro 4.1 software (Axon Instruments, Wetsbur BV, Leuden, The Netherland). Pixel intensities for each feature were integrated and median values were determined, and the local background was calculated. For each spot the intensities were corrected by subtracting the local background for both wavelengths, and only spots with signal intensities al least threefold above background signal intensities were included in the analysis. The median of the ratios of all spots was calculated and used to normalize all data points. From each feature, the log2 value of the average of the normalization ratios of the spots was calculated and used to display the data. In addition, fluorescence ratios were normalized for each microarray using the print-tip loess method and the background subtraction with the Diagnosis and Normalization Arrays Data tool. 24 The cut-off level was determined for each individual experiment after avering the ratios from the two color-swith hybridizations and subsequent for normalization, and calculate the mean and Standard derivations to define the cut-off level as means plus/minus two times the standard derivations. The clones that showed possible changes were submitted to the Database of Genomics Variants (http://projects.tcag.ca/variation/) and chromosomal Imbalances and Phenotype in Humans using Ensembl Resources (DECIPCHER: http: www sanger. ac.uk /PostGenomics/decipher/. Clustering Unsupervised clustering We converted the relative ratio value for each BAC clones in each sample to score of 1 (gain/amplified), 0 (no change), or -1 (loss) based on the 2 SD standards described above and analyzed with Cluster and TreeView) 25 (Cluster and TreeView software) based on the average linkage method with the centered correlation metric was used (or Pearson Uncentered). Supervised Sam analysis was used http://www-stat.stanford.edu/ tibs/SAM) 26 to identify BACs that segregate subgroups on MSC. BACs with an SD of zero across the data set before analysis were removed.
2010-05-25 | E-GEOD-10822 | biostudies-arrayexpress
Project description:While del(5q) MDS patients comprise a well-defined hematological subgroup, the molecular basis underlying its origin and the reason behind the relapse to lenalidomide remains unknown. Using scRNAseq on CD34+ progenitor cells from patients with del(5q) MDS we were able to identify cells harboring the deletion, enabling us to deeply characterize the transcriptional impact of this genetic insult on disease pathogenesis and treatment response. We found, across all patients, an enrichment of del(5q) cells in GMP and megakaryocyte-erythroid progenitors not described to date. Interestingly, both del(5q) and non-del(5q) cells presented similar transcriptional lesions when compared to progenitors from healthy individuals, indicating that all cells, and not only those harboring the deletion, are altered in these patients and may contribute to aberrant hematopoietic differentiation. However, GRN analysis revealed a group of regulons with aberrant activity in del(5q) cells that could be responsible for triggering altered hematopoiesis, pointing to a more prominent role of these cells in the phenotype of these patients. An analysis of del(5q) MDS patients achieving hematological response upon lenalidomide treatment showed that the drug reverted several transcriptional alterations in both del(5q) and non-del(5q) cells, but other lesions remained, which may be responsible for potential future relapses. Moreover, lack of hematological response was associated with the inability of lenalidomide to reverse transcriptional alterations. Collectively, this study provides a deep characterization of del(5q) and non-del(5q) cells at single-cell resolution, revealing previously unknown transcriptional alterations that could contribute to disease pathogenesis, or lack of responsiveness to lenalidomide.
2024-04-18 | GSE245452 | GEO
Project description:ZRSR2 mutant myelodysplastic syndromes
| PRJNA671387 | ENA
Project description:ZRSR2 mutant myelodysplastic syndromes
| PRJNA671388 | ENA
Project description:Lenalidome is a drug especially effective in low risk myelodysplastic syndromes (MDS) with isolated 5q deletion. However, 25% of the patients did not respond. TP53 mutations have been described to play a role in the disease progression, and karyotypic complexity also has an important impact in the outcome. We selected 53 MDS patients with 5q deletion and treated with lenalidomide and we studied by the following techniques: conventional G-banding cytogenetics (CC), single nucleotide polymorphism arrays (SNP-A) and sequencing, in order to assess their impact on treatment response and disease progression. Low karyotypic complexity (by CC), a high baseline platelet count (>280x103/L) and TP53 unmutated gene status are associated with the achievement of hematological response (P=0.005, P=0.008 and P=0.057, respectively). In a multivariate model, the most important predictors for lenalidomide failure are karyotypic complexity (P=0.014) and a platelet count below 280x103/L (P=0.042). Additionally, none of the TP53 mutated cases achieved complete cytogenetics response. Nevertheless, inclusion of defects by SNP-A did not allow for a better separation of responders and non responders. These findings constitute a useful reference data to be considered before lenalidomide treatment enrollment. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from bone marrow or peripheral blood and, in some cases, also lymphocytes CD3 isolated from peripheral blood samples. Copy number analyses of Affymetrix 250K and 6.0 SNP arrays were performed for 53 MDS with 5q deletion samples. There are also 30 samples from lymphocytes CD3 isolated from peripheral blood, which were used as germ-line DNA (control).
2013-07-01 | E-GEOD-35656 | biostudies-arrayexpress
Project description:Myeloid neoplasms, including myelodysplastic syndromes (MDS), are genetically heterogeneous disorders driven by clonal acquisition of somatic mutations in hematopoietic stem and progenitor cells (HPCs). The order of premalignant mutations and their impact on HPC self-renewal and differentiation remain poorly understood. We show that episomal reprogramming of MDS patient samples generates induced pluripotent stem cells from single premalignant cells with a partial complement of mutations, directly informing the temporal order of mutations in the individual patient. Reprogramming preferentially captured early subclones with fewer mutations, which were rare among single patient cells. To evaluate the functional impact of clonal evolution in individual patients, we differentiated isogenic MDS induced pluripotent stem cells harboring up to 4 successive clonal abnormalities recapitulating a progressive decrease in hematopoietic differentiation potential. SF3B1, in concert with epigenetic mutations, perturbed mitochondrial function leading to accumulation of damaged mitochondria during disease progression, resulting in apoptosis and ineffective erythropoiesis. Reprogramming also informed the order of premalignant mutations in patients with complex karyotype and identified 5q deletion as an early cytogenetic anomaly. The loss of chromosome 5q cooperated with TP53 mutations to perturb genome stability, promoting acquisition of structural and karyotypic abnormalities. Reprogramming thus enables molecular and functional interrogation of preleukemic clonal evolution, identifying mitochondrial function and chromosome stability as key pathways affected by acquisition of somatic mutations in MDS.
| S-EPMC6624967 | biostudies-literature