MYC activation and BCL2L11 silencing by a tumor virus through the large-scale reconfiguration of enhancer-promoter hubs [Bcell]
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ABSTRACT: 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 Epstein-Barr virus infection of CD19+ primary B cells. B cells physiologically activated by treatment with CD40 ligand and IL-4 were studied as a control.
ORGANISM(S): Homo sapiens
SUBMITTER: Simon Andrews
PROVIDER: E-GEOD-82148 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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