A mouse model of endemic Burkitt translocations reveals the long-range boundaries of Ig-mediated oncogene deregulation
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE48514 | GEO | 2013/07/04
SECONDARY ACCESSION(S): PRJNA210419
REPOSITORIES: GEO
Similar Datasets
Project description:Igh/Myc translocations underlie both sporadic Burkitt lymphoma (BL) and the endemic clinical form affecting African children infected with malaria. However, while sporadic translocations decapitate Myc from 5' proximal regulatory elements, most endemic events occur hundreds of kilobases away from Myc. The origin of these rearrangements and how they deregulate oncogenes at such distances remain unclear. Here we recapitulate endemic BL-like translocations in plasmacytomas from uracil N-glycosylase (UNG) deficient mice. We demonstrate that in these animals, rare endemic-like translocations arise from non-targeted DNA breaks at Myc loci. Deep-sequencing analyses revealed that the deregulated 3' Igh enhancer alpha physically interacts with and remodels 0.45Mb of translocated chromatin. The results thus explain the long-range deregulation of oncogenes in human and mouse B cell tumors. ChIP-Seq, 4C, and 1 RNASeq samples used to characterize mouse plasmacytoma cell lines and in vitro activated mouse B cells. Biological replicates are present for many of the samples.
2013-07-04 | E-GEOD-48514 | biostudies-arrayexpress
Project description:FOXO1 has an oncogenic role in adult germinal center derived lymphomas, in which mutations, predominately within the AKT recognition motif, cause nuclear retention of FOXO1 resulting in increased cell proliferation. To determine the prevalence and distribution of FOXO1 mutations in pediatric Burkitt lymphoma (BL), we sequenced a large number of sporadic and endemic BL patient samples. We report a high frequency of FOXO1 mutations in both sporadic and endemic BL at diagnosis, occurring in 23/78 (29%) and 48/89 (54%) samples respectively, as well as 8/16 (50%) cases at relapse. Mutations of T24 were the most common in sporadic BL but were rare in endemic cases, in which mutations of residue S22, also within the AKT recognition motif, were the most frequent. FOXO1 mutations were almost always present in the major tumor cell clone but were not associated with outcome. Analysis of other recurrent mutations reported in BL revealed that FOXO1 mutations were associated with mutations of DDX3X and ARID1A, but not MYC, TCF3/ID3 or members of the phosphatidylinositol 3’ OH kinase (PI3K) signaling pathway. We further show common nuclear retention of the FOXO1 protein, irrespective of mutation status, suggesting alternative unknown mechanisms for maintaining FOXO1 transcriptional activity in BL. CRISPR/Cas9 knockout of FOXO1 in an endemic cell line produced a significant decrease in cell proliferation, supporting an oncogenic role for FOXO1 in endemic BL. Thus, FOXO1 is frequently mutated in both sporadic and endemic BL and may offer a potential therapeutic target for pediatric BL patients worldwide.
| EGAS00001003719 | EGA
Project description:For sporadic Burkitt lymphoma (BL) few genetic lesions are known besides the pathognomonic IG-MYC translocations. Thirtynine molecularly-defined BL were analyzed with high-resolution single-nucleotide polymorphism chips for genomic imbalances and uniparental disomy (UPD). Imbalances were correlated to transcript profiling and selected miRNA analysis. Translocations affecting the MYC locus were studied by fluoresence in situ hybridization. We detected 528 copy number changes, defining 29 recurrently imbalanced regions. 518 regions of UPD were found, but these were rarely recurrent. Combined imbalance mapping and transcript profiling revealed a profound correlation between copy number and expression. Several recurrent imbalances affected the MYC pathway: The miRNA-supercluster 17-92 was frequently gained and the transcription factor E2F2 was recurrently deleted. Molecular BL lacking MYC translocations showed MYC gains. Amplifications of the polymerase iota gene were associated with increased genomic instability. The present findings suggests that UPDs play no major role in the pathogenesis of BL, whereas some genes may contribute to BL development through gene dosage effects. Amplifications of the polymerase iota gene may be functionally linked with increased genomic instability in BL. The pattern and rarity of chromosomal changes detectable even at the high resolution employed here, together with aberrations of genes regulating MYC activity, support that deregulation of the MYC pathway is the major force driving BL pathogenesis, but show that this deregulation is more complex than previously known.
2010-12-07 | GSE21597 | GEO
Project description:<p>This genomic landscape of Burkitt lymphoma represents a multimodal sequencing of tumors and control tissues and individuals to better understand the etiology, and molecular pathogenesis of Burkitt lymphoma including the roles of the associated Plasmodium falciparum malaria and EBV infections. Comprehensive sequencing set includes genomic, transcriptomic, and epigenomic datasets in concert with variable clinical phenotypes and outcome information such as anatomical presentation site, in-hospital survival rates, and EBV genome type. The initial deposit represents polyA RNA-seq from tumor specimens from 28 cases of endemic BL and 2 cases of sporadic BL.</p> <p><b>For initial transcriptome analysis see: Kaymaz et al.</b> Comprehensive Transcriptome and Mutational Profiling of Endemic Burkitt Lymphoma Reveals EBV Type-specific Difference. Molecular Cancer Research: MCR, January. doi:10.1158/1541-7786.MCR-16-0305.<br/> <b>For general overview of cohort study see:</b> Buckle et al. Factors influencing survival among Kenyan children diagnosed with endemic Burkitt lymphoma between 2003 and 2011: A historical cohort study. Int J Cancer. 15:1231, 2016.</p>
| phs001282 | dbGaP
Project description:For sporadic Burkitt lymphoma (BL) few genetic lesions are known besides the pathognomonic IG-MYC translocations. Thirtynine molecularly-defined BL were analyzed with high-resolution single-nucleotide polymorphism chips for genomic imbalances and uniparental disomy (UPD). Imbalances were correlated to transcript profiling and selected miRNA analysis. Translocations affecting the MYC locus were studied by fluoresence in situ hybridization. We detected 528 copy number changes, defining 29 recurrently imbalanced regions. 518 regions of UPD were found, but these were rarely recurrent. Combined imbalance mapping and transcript profiling revealed a profound correlation between copy number and expression. Several recurrent imbalances affected the MYC pathway: The miRNA-supercluster 17-92 was frequently gained and the transcription factor E2F2 was recurrently deleted. Molecular BL lacking MYC translocations showed MYC gains. Amplifications of the polymerase iota gene were associated with increased genomic instability. The present findings suggests that UPDs play no major role in the pathogenesis of BL, whereas some genes may contribute to BL development through gene dosage effects. Amplifications of the polymerase iota gene may be functionally linked with increased genomic instability in BL. The pattern and rarity of chromosomal changes detectable even at the high resolution employed here, together with aberrations of genes regulating MYC activity, support that deregulation of the MYC pathway is the major force driving BL pathogenesis, but show that this deregulation is more complex than previously known. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from whole tissue. Copy number and LOH analysis of 500K SNP arrays was performed for 30 molecularly-defined Burkitt lymphomas. Genotyping was performed using the BRLMM-algorithm. Only a single 250k Chip was performed for nine additional Burkitts. 20 normal references (10 of those hybridized to nsp-chips) extracted from healthy blood donors, used as normals in the analysis in addition to the HapMap references provided by Affymetrix, are included in the set.
2010-12-07 | E-GEOD-21597 | biostudies-arrayexpress
Project description:Sporadic Burkitt lymphoma (sBL) can be delineated from diffuse large B-cell lymphoma (DLBCL) by a very homogeneous mRNA expression signature. However, it remained unclear whether all three BL variants – sBL, endemic BL (eBL) and immunodeficiency-associated BL (HIV-BL) – represent a uniform biological entity despite their differences in geographical occurrence, association with immunodeficiency and/or incidence of EBV infection. To address this issue, we generated micro RNA (miRNA) profiles from 18 eBL, 31 sBL and 15 HIV-BL cases. In addition, we analyzed the miRNA expression of 86 DLBCL to determine whether miRNA profiles recapitulate the molecular differences between BL and DLBCL evidenced by mRNA profiling. A signature of 38 miRNAs enriched in MYC regulated and NF-kB pathway associated miRNAs was obtained that differentiated BL from DLBCL. The miRNA profiles of sBL and eBL displayed only 6 differentially expressed miRNAs, whereas HIV and EBV infection had no impact on the miRNA profile of BL. In conclusion, miRNA profiling confirms that BL and DLBCL represent distinct lymphoma categories and demonstrates that the three BL variants are representatives of the same biological entity with only marginal miRNA expression differences between eBL and sBL. Archival tumor specimens of 86 diffuse large B-cell lymphoma (DLBCL) and 64 Burkitt lymphoma (BL) patients were obtained. The DLBCL samples have previously been reviewed by a panel of expert hematopathologists and their clinical data were published as part of the RiCOVER-60 trial. The diagnosis of all BL cases was confirmed by histopathology review according to the criteria of the WHO classification. Based on their geographical origin, 31 BL samples were designated as sporadic BL (sBL) and 18 samples as endemic BL (eBL). Fifteen BL cases were diagnosed as immunodeficiency-associated BL (HIV-BL). Of the 18 eBL 14 cases were EBV+ (87.5%), 2 samples were EBV- (12.5%) and for 2 eBL cases the EBV status was unknown. Of the sBL samples 26 were EBV- (86.7%), 4 cases were EBV+ (13.3%) and for 1 case the EBV status was not evaluable. Among the HIV-BL 5 (33.3%) were EBV+, whereas 10 (66.7%) were EBV-.
2011-07-17 | E-GEOD-22420 | biostudies-arrayexpress
Project description:A hallmark feature of mature B cell tumors in humans is the occurrence of balanced chromosomal translocations, most often involving immunoglobulin (Ig) genes and a wide range of partner genes. Ig/oncogene translocations also occur in mice. However, they are regularly associated with a specific tumor type only for plasmacytomas (PCT), a neoplasm that features Ig/Myc translocations in over 95% of cases. In addition to the contribution of Myc signaling to mouse B cell lymphomagenesis, to identify any other oncogenic pathway in mouse PCT, expression profiling of mouse PCT was performed. six biological replicates of mouse PCT from IL-6 TG mice vs. five biological replicates of normal spleen.
2010-05-19 | E-GEOD-12157 | biostudies-arrayexpress
Project description:A hallmark feature of mature B cell tumors in humans is the occurrence of balanced chromosomal translocations, most often involving immunoglobulin (Ig) genes and a wide range of partner genes. Ig/oncogene translocations also occur in mice. However, they are regularly associated with a specific tumor type only for plasmacytomas (PCT), a neoplasm that features Ig/Myc translocations in over 95% of cases. In addition to the contribution of Myc signaling to mouse B cell lymphomagenesis, to identify any other oncogenic pathway in mouse PCT, expression profiling of mouse PCT was performed.
2008-09-30 | GSE12157 | GEO
Project description:Cohesin extrusion is thought to play a central role in establishing the architecture of mammalian genomes. However, extrusion has not been visualized in vivo, and thus, its functional impact and energetics are unknown. Using ultra-deep Hi-C, we show that loop domains form by a process that requires cohesin ATPases. Once formed, however, loops and compartments are maintained for hours without energy input. Strikingly, without ATP, we observe the emergence of hundreds of CTCF-independent loops that link regulatory DNA. We also identify architectural "stripes" where a loop anchor interacts with entire domains at high frequency. Stripes often tether super-enhancers to cognate promoters, and in B cells, they facilitate Igh transcription and recombination. Stripe anchors represent major hotspots for topoisomerase-mediated lesions, which promote chromosomal translocations and cancer. In plasmacytomas, stripes can deregulate Igh-translocated oncogenes. We propose that higher organisms have coopted cohesin extrusion to enhance transcription and recombination, with implications for tumor development.
2018-05-01 | GSE98119 | GEO
Project description:Chromosomal translocations are important drivers of haematological malignancies whereby proto-oncogenes are activated by juxtaposition with super-enhancers, often called super-enhancer hijacking. We analysed the epigenomic consequences of rearrangements between the enhancers of the immunoglobulin heavy chain locus (IGH) and proto-oncogene CCND1 that are common in B-cell malignancies. By integrating BLUEPRINT epigenomic data with DNA breakpoint detection, we characterised the normal chromatin landscape of the human IGH locus and its dynamics after pathological genomic rearrangement. We detected an H3K4me3 broad domain (BD) within the IGH locus of healthy B-cells that was absent in samples with IGH-CCND1 translocations. The appearance of H3K4me3-BD over CCND1 in the latter was associated with overexpression and extensive chromatin accessibility of this locus. We observed similar cancer-specific H3K4me3-BDs associated with super-enhancer hijacking of other common oncogenes in B-cell (MAF, MYC and FGFR3) and in T-cell malignancies (LMO2, TLX3 and TAL1). Our analysis suggests that H3K4me3-BDs are created by super-enhancers and supports the new concept of epigenomic translocation, where the relocation of H3K4me3-BDs accompanies the translocation of super-enhancers.
2020-08-12 | GSE151556 | GEO