Homo sapiens
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ABSTRACT:
PROVIDER: PRJNA143515 | ENA |
REPOSITORIES: ENA
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Project description:Among acute myeloid leukemias (AML) with normal karyotype (CN-AML), NPM1 and CEBPA mutations define WHO provisional entities accounting for ~60% of cases, but the remaining ~40% remains poorly characterized. By whole exome-sequencing (WES) of one CN-AML patient lacking mutations in NPM1, CEBPA, FLT3, MLL-PTD and IDH1, we newly identified a clonal somatic mutation in BCOR (BCL6 co-repressor), a gene located in chromosome X. Further analyses showed that BCOR mutations occurred in 11/262 (4.2%) CN-AML cases and represented a substantial fraction (14/82, 17.1%) of CN-AML patients showing the same genetic background as the index patient subjected to WES. BCOR somatic mutations were: i) disruptive events similar to germline BCOR mutations causing the oculo-cranio-facial-dental (OCFD) genetic syndrome; ii) associated with markedly decreased BCOR mRNA levels, absence of full-length BCOR and absent or low expression of a truncated BCOR protein; iii) almost mutually exclusive with NPM1 mutations and frequently associated with DNMT3A and RUNX1 mutations, pointing to a cooperation between these events. Finally, BCOR mutations correlated with poor outcome among a cohort of 160 CN-AML patients (28% versus 66% overall survival at 2 yrs, P=0.024). Our results implicate for the first time BCOR in the pathogenesis of CN-AML without NPM1 mutations. AML samples with normal karyotype were studied. Molecular analyses were performed for BCOR mutations. 12 BCOR wild-type cases and 12 BCOR mutated cases were hybridized to gene expression micro-arrays.
2011-12-16 | E-GEOD-30442 | biostudies-arrayexpress
Project description:Among acute myeloid leukemias (AML) with normal karyotype (CN-AML), NPM1 and CEBPA mutations define WHO provisional entities accounting for ~60% of cases, but the remaining ~40% remains poorly characterized. By whole exome-sequencing (WES) of one CN-AML patient lacking mutations in NPM1, CEBPA, FLT3, MLL-PTD and IDH1, we newly identified a clonal somatic mutation in BCOR (BCL6 co-repressor), a gene located in chromosome X. Further analyses showed that BCOR mutations occurred in 11/262 (4.2%) CN-AML cases and represented a substantial fraction (14/82, 17.1%) of CN-AML patients showing the same genetic background as the index patient subjected to WES. BCOR somatic mutations were: i) disruptive events similar to germline BCOR mutations causing the oculo-cranio-facial-dental (OCFD) genetic syndrome; ii) associated with markedly decreased BCOR mRNA levels, absence of full-length BCOR and absent or low expression of a truncated BCOR protein; iii) almost mutually exclusive with NPM1 mutations and frequently associated with DNMT3A and RUNX1 mutations, pointing to a cooperation between these events. Finally, BCOR mutations correlated with poor outcome among a cohort of 160 CN-AML patients (28% versus 66% overall survival at 2 yrs, P=0.024). Our results implicate for the first time BCOR in the pathogenesis of CN-AML without NPM1 mutations.
2011-12-16 | GSE30442 | GEO
Project description:BCOR is a component of a variant Polycomb group repressive complex 1 (PRC1) complex. Recently, we and others reported recurrent somatic BCOR loss-of-function mutations in myelodysplastic syndrome and acute myelogenous leukaemia (AML). However the role of BCOR in normal hematopoiesis is largely unknown. Here, we explored the function of BCOR in myeloid cells using myeloid murine cell models with Bcor conditional loss-of-function or overexpression alleles. Bcor mutant bone marrow cells showed significantly higher proliferation and differentiation rates with reduced protein levels of RING1B, a ubiquitin ligase subunit of PRC1 family complexes. Global RNA expression profiling in murine cells and AML patient samples with BCOR loss-of-function mutation suggested that loss of BCOR expression is associated with proliferation and myeloid differentiation and decreased stem cell quiescence. Further, we used a MLL-AF9 murine model of AML and found that loss of Bcor increased serial replating efficiency, enhanced MLL-AF9 in blocking cell differentiation, and increased expression of Evi1 which is associated with leukemic transformation. Our results strongly suggest that BCOR plays an indispensable role in maintaining hematopoietic stem cell (HSC) quiescence by inhibiting myeloid stem cell proliferation and differentiation and offer a mechanistic explanation for how BCOR regulates gene expression such as Hox genes. Normal karyotype AML primary cells with either wild type BCOR (6 cases) or destructive mutated BCOR (6 cases) were collected and subjected to RNA expression microarray study
2015-12-31 | E-GEOD-69565 | biostudies-arrayexpress
Project description:To decipher the role of Ezh2 mutations in leukemia we transplanted mice secondarily with BRSST (Bcor, Runx1, Sh2b3, Stag2, Tet2) sgRNAs with or without sgEzh2 to observe development of myeloid leukemia. Whole BM was used for ChIP-Seq analysis of histone modifications.
2023-04-30 | GSE173133 | GEO
Project description:Recurrent loss-of-function mutations of BCL6 co-repressor (BCOR) gene are found in about 4% of AML patients with normal karyotype and are associated with DNMT3a mutations and poor prognosis. Therefore, new anti-leukemia treatments and mouse models are needed for this combinatorial AML genotype. For this purpose, we first generated a Bcor-/- knock-out mouse model characterized by impaired erythroid development (macrocytosis and anemia) and enhanced thrombopoiesis, which are both features of myelodysplasia/myeloproliferative neoplasms. We then created and characterized double Bcor-/-/Dnmt3a-/- knock-out mice. Interestingly, these animals developed a fully penetrant acute erythroid leukemia (AEL) characterized by leukocytosis secondary to the expansion of blasts expressing c-Kit+ and the erythroid marker Ter119, macrocytic anemia and progressive reduction of the thrombocytosis associated with loss of Bcor alone. Transcriptomic analysis of double knock-out bone marrow progenitors revealed that aberrant erythroid skewing was induced by epigenetic changes affecting specific transcriptional factors (GATA1-2) and cell-cycle regulators (Mdm2, Tp53). These findings prompted us to investigate the efficacy of demethylating agents in AEL, with significant impact on progressive leukemic burden and mice overall survival. Information gained from our model expands the knowledge on the biology of AEL and may help designing new rational treatments for patients suffering from this high-risk leukemia.
2021-09-01 | GSE158018 | GEO
Project description:Normal Karyotype acute myeloid leukemia (NK-AML) represents approximately 50% of all cases of AML which patients develop. Most AML cell lines are highly abnormal and therefore not good models for investigating NK-AML biology a novel AML cell line, CG-SH, was recently estabished and here we characterize the gene expression and mutations present through high-throughput sequencing of RNA and genomic DNA using a HiSeq 2000 The overall design of the experiment was to characterize, at single base pair resolution, all of the genetic defects present in a novel normal karyotype cell line, CG-SH
2013-12-31 | E-GEOD-40199 | biostudies-arrayexpress
Project description:aCGH was performed on acute myeloid leukemia samples (vs constitutive Normal matched tissue) derived from a mouse model of mutant NPM1, NRAS and FLIT3 normal karyotype leukemia. The purpose of these assays was to identify common and potentially co-operative genetic phenomena in NPM1c positive mouse leukemias.
2017-07-30 | E-MTAB-5356 | biostudies-arrayexpress
Project description:BCOR is a component of a variant Polycomb group repressive complex 1 (PRC1) complex. Recently, we and others reported recurrent somatic BCOR loss-of-function mutations in myelodysplastic syndrome and acute myelogenous leukaemia (AML). However the role of BCOR in normal hematopoiesis is largely unknown. Here, we explored the function of BCOR in myeloid cells using myeloid murine cell models with Bcor conditional loss-of-function or overexpression alleles. Bcor mutant bone marrow cells showed significantly higher proliferation and differentiation rates with reduced protein levels of RING1B, a ubiquitin ligase subunit of PRC1 family complexes. Global RNA expression profiling in murine cells and AML patient samples with BCOR loss-of-function mutation suggested that loss of BCOR expression is associated with proliferation and myeloid differentiation and decreased stem cell quiescence. Further, we used a MLL-AF9 murine model of AML and found that loss of Bcor increased serial replating efficiency, enhanced MLL-AF9 in blocking cell differentiation, and increased expression of Evi1 which is associated with leukemic transformation. Our results strongly suggest that BCOR plays an indispensable role in maintaining hematopoietic stem cell (HSC) quiescence by inhibiting myeloid stem cell proliferation and differentiation and offer a mechanistic explanation for how BCOR regulates gene expression such as Hox genes. We took advantage of a mouse conditional Bcor allele which has exons 9 and 10 been flanked by LoxP sites to allow their removal via expression of Cre recombinase. Excision of these exons results in a frame shift and a premature stop codon causing nonsense mediated decay and/or carboxy-terminal deletion of the BCOR protein. CD34+ cells were sorted from control or Bcor mutant cells cultured under myeloid stem/progenitor conditions (IL3, 6 and SCF). We used microarrays to detail the global programme of gene expression in Control and Bcor mutant CD34+ cells.
2015-12-31 | E-GEOD-69620 | biostudies-arrayexpress
Project description:Except for the well-known association with Down syndrome, there is little information on the genetic factors predisposing to acute myeloid leukemia. Germinal gene copy-number variations may represent risk factors for the disease. To identify copy number variants present in both normal and leukemic cells, we compared the Comparative Genomic Hybridization profiles of the blasts and healthy cells (CD3+ cells or peripheral lymphocytes during remission) of 13 patients (SET-A) and the blasts of a further 12 normal-karyotype acute myeloid leukemia patients (SET-B) for which only blasts DNA were available.
2015-10-01 | E-MTAB-2609 | biostudies-arrayexpress
Project description:Normal Karyotype acute myeloid leukemia (NK-AML) represents approximately 50% of all cases of AML which patients develop. Most AML cell lines are highly abnormal and therefore not good models for investigating NK-AML biology a novel AML cell line, CG-SH, was recently estabished and here we characterize the gene expression and mutations present through high-throughput sequencing of RNA and genomic DNA using a HiSeq 2000
2013-12-31 | GSE40199 | GEO