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: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:DNMT inhibitors (DNMTi) are finally approved for AML/MDS, also based on their activity in patients with high-risk cytogenetics (often monosomal karyotype) such as -5/del(5q) or -7/del(7q), often - but not always - harboring TP53-mutations. Several studies provided evidence for aberrant hypermethylation/silencing on monoallelic gene loci, including tumor suppressor genes. We hypothesized that transcriptional repression on monosomal gene loci may be preferentially reversed by DNMTi. Using an unbiased RNA-seq approach we aimed to identify preferentially regulated genes in cells monoallelic for chromosome 7q.
2021-03-09 | GSE140347 | GEO
Project description:DNMT inhibitors (DNMTi) are finally approved for AML/MDS, also based on their activity in patients with high-risk cytogenetics (often monosomal karyotype) such as -5/del(5q) or -7/del(7q), often - but not always - harboring TP53-mutations. Several studies provided evidence for aberrant hypermethylation/silencing on monoallelic gene loci, including tumor suppressor genes. We hypothesized that transcriptional repression on monosomal gene loci may be preferentially reversed by DNMTi. Using an unbiased RNA-seq approach we aimed to identify preferentially regulated genes in cells monoallelic for chromosome 7q.
2021-03-09 | GSE138438 | GEO
Project description:ZRSR2 mutant myelodysplastic syndromes
| PRJNA671388 | ENA
Project description:ZRSR2 mutant myelodysplastic syndromes
| PRJNA671387 | 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:AML with complex karyotype (CK-AML) is characterized by a high frequency of TP53 alteration (loss and/or mutation). TP53-altered CK-AML were characterized by a higher degree of genomic complexity (aberrations per case, 14.30 vs. 6.16; P<.0001), and by a higher frequency of specific copy number alterations, such as -5/5q-, -7/7q-, -16/16q-, -18/18q-, +1/+1p, and +11/+11q/amp11q13~25; among CK-AML, TP53-altered more frequently exhibited a monosomal karyotype (MK). Patients with TP53 alterations were older and had significantly lower complete remission rates, inferior event-free, relapse-free, and overall survival. In multivariable analysis for overall survival, TP53 alterations, white blood cell counts, and age were the only significant factors. In conclusion, TP53 is the most frequently known altered gene in CK-AML. TP53 alterations are associated with older age, genomic complexity, specific DNA copy number alterations, MK, and dismal outcome. In multivariable analysis, TP53 alteration is the most important prognostic factor in CK-AML, outweighing all other variables, including the MK category.
2012-08-27 | GSE34542 | GEO