Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA391866 | ENA |
REPOSITORIES: ENA
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Project description:Whilst the association of Epstein-Barr virus (EBV) with Burkitt lymphoma (BL) has long been recognized, the precise role of the virus in BL pathogenesis is not fully resolved. EBV can be lost spontaneously from some BL cell lines, and these EBV-loss lymphoma cells reportedly have a survival disadvantage. We have generated an extensive panel of EBV-loss clones from multiple BL backgrounds and examined their phenotype comparing them to their isogenic EBV-positive counterparts. Whilst loss of EBV from BL cells is rare, it is consistently associated with an enhanced predisposition to undergo apoptosis and reduced tumorigenicity in vivo. We investigated whether there were common gene expression changes between EBV-positive and loss clones derived for four endemic Burkitt lyphoma cell lines that could explain the apoptosis sensitivity of clones that had lost EBV.
2018-01-25 | GSE100458 | GEO
Project description:In this study we have investigated the gene expression profiles of three different types of subclone all generated by single cell cloning of the same parental EBV positive Burkitt lymphoma cell line Awia-BL. These included EBV negative clones which have lost the virus episome, EBV positive clones with a conventional Latency I form of infection and EBV positive clones with an atypical Wp-restricted form of infection.
2013-01-22 | GSE42867 | GEO
Project description:In this study we have investigated the gene expression profiles of three different types of subclone all generated by single cell cloning of the same parental EBV positive Burkitt lymphoma cell line Awia-BL. These included EBV negative clones which have lost the virus episome, EBV positive clones with a conventional Latency I form of infection and EBV positive clones with an atypical Wp-restricted form of infection. Gene expression was compared between two different EBV negative clones (both performed in biological duplicate), four different Latency I clones and four different Wp-restricted clones using HG U133 Plus 2.0 gene chip arrays.
2013-01-22 | E-GEOD-42867 | biostudies-arrayexpress
Project description:Transition of Akata Burkitt lymphoma (BL) cells from a malignant to nonmalignant phenotype upon loss of Epstein-Barr virus (EBV) genomes in vitro is evidence for a viral contribution to tumor maintenance despite the tightly restricted pattern of EBV gene expression in BL. Akata cells retaining virus manifest increased resistance to apoptosis under growth limiting conditions, although ambiguity exists regarding the exact mechanisms involved. By examining global cellular gene expression differences in Akata subclones that had either retained or lost EBV, we identified spermidine/spermine N1-acetyltransferase (SSAT), an inducible acetylating enzyme whose catabolism of polyamines affects both apoptosis and cell growth, as one of a limited number of cellular genes up-regulated upon loss of EBV. Keywords: Disease state analysis We used Affymetrix microarrays to examine variations in global gene expression between the paired EBV-positive (1B6) and EBV-negative (2A8) Akata Burkitt's lymphoma clones. EBV-negative Akata clones were generated by treatment with hydroxyurea, an inhibitor of ribonucleotide reductase that forced rapid loss of EBV episomes and compared to their EBV-positive counterparts. Logarithmically growing EBV-negative and positive Akata EBV clones were seeded at 2.5x10^5 cells/ml in RPMI1640 supplemented with 10% fetal bovine serum, 2mM glutamine, and 100units/ml penicillin/streptomycin. The next day, the cells were incubated for 4 hours in media containing 1% fetal bovine serum (low serum), 2mM glutatmine and 100units/ml penicillin/streptomycin to begin selection of the Akata tumor phenotype. The short incubation time was intended to minimize cell death and other potential downstream effects of low serum treatment, while at the same time initiating expression changes contributing to the tumorigenic phenotype.
2010-01-19 | E-GEOD-19761 | biostudies-arrayexpress
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:Epstein-Barr virus (EBV) causes endemic Burkitt lymphoma and immunosuppression-related lymphomas. These B-cell malignancies arise by distinct transformation pathways and utilize divergent viral and host expression programs. To identify host dependency factors elicited by EBV latent-infection states, we performed parallel genome-wide CRISPR/Cas9 screens in Burkitt lymphoma (BL) and lymphoblasotid cell lines (LCL). Our results highlighted 57 BL and 87 LCL genes selectively critical for their growth and survival. LCL hits were enriched for EBV-induced genes, including viral super-enhancer targets and multiple kinases. We uncovered key CD19/CD81 roles in EBV membrane protein-driven PI3K/AKT activation and mechanisms by which EBV evades tumor suppressor responses to its growth program. LMP1-induced cFLIP was critical for LCL defense against TNFa-mediated programmed cell death, while EBV-induced BATF/IRF4 were critical for LCL BIM suppression and MYC induction. EBV super-enhancer targeted IRF2 protected LCLs against BLIMP1 responses. Collectively, our results identify host/pathogen interaction-driven synthetic lethal targets for therapeutic intervention.
2017-05-11 | GSE93681 | GEO
Project description:Lymphomagenesis in the presence of deregulated MYC expression requires suppression of MYC-driven apoptosis, often through downregulation of the pro-apoptotic BCL2L11 gene (Bim). Transcription factors (EBNAs) encoded by the lymphoma-associated Epstein-Barr virus (EBV) activate MYC and silence BCL2L11. We show that EBNA2 upregulates MYC by reconfiguring the 3 Mb MYC locus to increase upstream and decrease downstream enhancer-promoter interactions. EBNA2 recruits the SWI/SNF ATPase BRG1 to drive MYC enhancer-promoter interactions. MYC-Immunoglobulin translocation breakpoints in EBV-positive endemic Burkitt lymphoma localise to EBNA2-activated upstream MYC regions. This implicates EBV in the genesis and localisation of breakpoints, since active enhancers are targeted by activation-induced cytidine deaminase. We identify a novel haematopoietic BCL2L11 enhancer hub that is inactivated by EBNA3A and EBNA3C through recruitment of the H3K27 methyltransferase EZH2. Reversal of enhancer inactivation using an EZH2 inhibitor upregulates BCL2L11 and induces apoptosis. EBV therefore drives lymphomagenesis by hijacking long-range enhancer hubs and specific cellular co-factors.
2016-08-04 | GSE82149 | GEO
Project description:Lymphomagenesis in the presence of deregulated MYC expression requires suppression of MYC-driven apoptosis, often through downregulation of the pro-apoptotic BCL2L11 gene (Bim). Transcription factors (EBNAs) encoded by the lymphoma-associated Epstein-Barr virus (EBV) activate MYC and silence BCL2L11. We show that EBNA2 upregulates MYC by reconfiguring the 3 Mb MYC locus to increase upstream and decrease downstream enhancer-promoter interactions. EBNA2 recruits the SWI/SNF ATPase BRG1 to drive MYC enhancer-promoter interactions. MYC-Immunoglobulin translocation breakpoints in EBV-positive endemic Burkitt lymphoma localise to EBNA2-activated upstream MYC regions. This implicates EBV in the genesis and localisation of breakpoints, since active enhancers are targeted by activation-induced cytidine deaminase. We identify a novel haematopoietic BCL2L11 enhancer hub that is inactivated by EBNA3A and EBNA3C through recruitment of the H3K27 methyltransferase EZH2. Reversal of enhancer inactivation using an EZH2 inhibitor upregulates BCL2L11 and induces apoptosis. EBV therefore drives lymphomagenesis by hijacking long-range enhancer hubs and specific cellular co-factors.
2016-08-04 | GSE82148 | GEO
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:Lymphomagenesis in the presence of deregulated MYC expression requires suppression of MYC-driven apoptosis, often through downregulation of the pro-apoptotic BCL2L11 gene (Bim). Transcription factors (EBNAs) encoded by the lymphoma-associated Epstein-Barr virus (EBV) activate MYC and silence BCL2L11. We show that EBNA2 upregulates MYC by reconfiguring the 3 Mb MYC locus to increase upstream and decrease downstream enhancer-promoter interactions. EBNA2 recruits the SWI/SNF ATPase BRG1 to drive MYC enhancer-promoter interactions. MYC-Immunoglobulin translocation breakpoints in EBV-positive endemic Burkitt lymphoma localise to EBNA2-activated upstream MYC regions. This implicates EBV in the genesis and localisation of breakpoints, since active enhancers are targeted by activation-induced cytidine deaminase. We identify a novel haematopoietic BCL2L11 enhancer hub that is inactivated by EBNA3A and EBNA3C through recruitment of the H3K27 methyltransferase EZH2. Reversal of enhancer inactivation using an EZH2 inhibitor upregulates BCL2L11 and induces apoptosis. EBV therefore drives lymphomagenesis by hijacking long-range enhancer hubs and specific cellular co-factors. A study of MYC enhancer-promoter interactions using 4C on induction of MYC by the Epstein-Barr virus transcription factor EBNA2 in a lymphoblastoid cell line.
2016-08-04 | E-GEOD-82149 | biostudies-arrayexpress