Enhancer Sequence Variants and Transcription Factor Deregulation Synergize to Construct Pathogenic Regulatory Circuits in B Cell Lymphoma
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE62246 | GEO | 2015/01/15
SECONDARY ACCESSION(S): PRJNA263570
REPOSITORIES: GEO
Similar Datasets
Project description:Most B-cell lymphomas arise in the germinal center (GC), where humoral immune responses evolve from potentially oncogenic cycles of mutation, proliferation, and clonal selection. Although lymphoma gene expression diverges significantly from GC B cells, underlying mechanisms that alter the activities of corresponding regulatory elements (REs) remain elusive. Here we define the complete pathogenic circuitry of human follicular lymphoma (FL), which activates or decommissions REs from normal GC B cells and commandeers enhancers from other lineages. Moreover, independent sets of transcription factors, whose expression was deregulated in FL, targeted commandeered versus decommissioned REs. Our approach revealed two distinct subtypes of low-grade FL, whose pathogenic circuitries resembled GC B or activated B cells. FL-altered enhancers also were enriched for sequence variants, including somatic mutations, which disrupt transcription-factor binding and expression of circuit-linked genes. Thus, the pathogenic regulatory circuitry of FL reveals distinct genetic and epigenetic etiologies for GC B-cell transformation.
| S-EPMC4302272 | biostudies-literature
Project description:Most B cell lymphomas arise in the germinal center (GC), where humoral immune responses evolve from potentially oncogenic cycles of mutation, proliferation, and clonal selection. Although lymphoma gene expression diverges significantly from GC-B cells, underlying mechanisms that alter the activities of corresponding regulatory elements (REs) remain elusive. Here we define the complete pathogenic circuitry of human follicular lymphoma (FL), which activates or decommissions transcriptional circuits from normal GC-B cells and commandeers enhancers from other lineages. Moreover, independent sets of transcription factors, whose expression is deregulated in FL, target commandeered versus decommissioned REs. Our approach reveals two distinct subtypes of low-grade FL, whose pathogenic circuitries resemble GC-B or activated B cells. Remarkably, FL-altered enhancers also are enriched for sequence variants, including somatic mutations, which disrupt transcription factor binding and expression of circuit-linked genes. Thus, the pathogenic regulatory circuitry of FL reveals distinct genetic and epigenetic etiologies for GC-B transformation. Expression profiles of follicular lymphoma, centrocyte and peripheral blood B cells were generated by deep sequencing, using Illumina Hi-Seq 2000.
2015-01-15 | E-GEOD-62241 | biostudies-arrayexpress
Project description:Most B cell lymphomas arise in the germinal center (GC), where humoral immune responses evolve from potentially oncogenic cycles of mutation, proliferation, and clonal selection. Although lymphoma gene expression diverges significantly from GC-B cells, underlying mechanisms that alter the activities of corresponding regulatory elements (REs) remain elusive. Here we define the complete pathogenic circuitry of human follicular lymphoma (FL), which activates or decommissions transcriptional circuits from normal GC-B cells and commandeers enhancers from other lineages. Moreover, independent sets of transcription factors, whose expression is deregulated in FL, target commandeered versus decommissioned REs. Our approach reveals two distinct subtypes of low-grade FL, whose pathogenic circuitries resemble GC-B or activated B cells. Remarkably, FL-altered enhancers also are enriched for sequence variants, including somatic mutations, which disrupt transcription factor binding and expression of circuit-linked genes. Thus, the pathogenic regulatory circuitry of FL reveals distinct genetic and epigenetic etiologies for GC-B transformation.
2015-01-15 | GSE61912 | GEO
Project description:Most B cell lymphomas arise in the germinal center (GC), where humoral immune responses evolve from potentially oncogenic cycles of mutation, proliferation, and clonal selection. Although lymphoma gene expression diverges significantly from GC-B cells, underlying mechanisms that alter the activities of corresponding regulatory elements (REs) remain elusive. Here we define the complete pathogenic circuitry of human follicular lymphoma (FL), which activates or decommissions transcriptional circuits from normal GC-B cells and commandeers enhancers from other lineages. Moreover, independent sets of transcription factors, whose expression is deregulated in FL, target commandeered versus decommissioned REs. Our approach reveals two distinct subtypes of low-grade FL, whose pathogenic circuitries resemble GC-B or activated B cells. Remarkably, FL-altered enhancers also are enriched for sequence variants, including somatic mutations, which disrupt transcription factor binding and expression of circuit-linked genes. Thus, the pathogenic regulatory circuitry of FL reveals distinct genetic and epigenetic etiologies for GC-B transformation.
2015-01-15 | GSE62241 | GEO
Project description:Most B cell lymphomas arise in the germinal center (GC), where humoral immune responses evolve from potentially oncogenic cycles of mutation, proliferation, and clonal selection. Although lymphoma gene expression diverges significantly from GC-B cells, underlying mechanisms that alter the activities of corresponding regulatory elements (REs) remain elusive. Here we define the complete pathogenic circuitry of human follicular lymphoma (FL), which activates or decommissions transcriptional circuits from normal GC-B cells and commandeers enhancers from other lineages. Moreover, independent sets of transcription factors, whose expression is deregulated in FL, target commandeered versus decommissioned REs. Our approach reveals two distinct subtypes of low-grade FL, whose pathogenic circuitries resemble GC-B or activated B cells. Remarkably, FL-altered enhancers also are enriched for sequence variants, including somatic mutations, which disrupt transcription factor binding and expression of circuit-linked genes. Thus, the pathogenic regulatory circuitry of FL reveals distinct genetic and epigenetic etiologies for GC-B transformation. Molecular profiling of follicular lymphoma, resting peripheral blood and tonsillar B cells using Formaldehyde-Assisted Isolation of Regulatory Elements (FAIRE) and chromatin immunoprecipitation (H3ac and H3K27ac).
2015-01-15 | E-GEOD-62245 | biostudies-arrayexpress
Project description:Most B cell lymphomas arise in the germinal center (GC), where humoral immune responses evolve from potentially oncogenic cycles of mutation, proliferation, and clonal selection. Although lymphoma gene expression diverges significantly from GC-B cells, underlying mechanisms that alter the activities of corresponding regulatory elements (REs) remain elusive. Here we define the complete pathogenic circuitry of human follicular lymphoma (FL), which activates or decommissions transcriptional circuits from normal GC-B cells and commandeers enhancers from other lineages. Moreover, independent sets of transcription factors, whose expression is deregulated in FL, target commandeered versus decommissioned REs. Our approach reveals two distinct subtypes of low-grade FL, whose pathogenic circuitries resemble GC-B or activated B cells. Remarkably, FL-altered enhancers also are enriched for sequence variants, including somatic mutations, which disrupt transcription factor binding and expression of circuit-linked genes. Thus, the pathogenic regulatory circuitry of FL reveals distinct genetic and epigenetic etiologies for GC-B transformation.
2015-01-15 | GSE62245 | GEO
Project description:Enhancer Sequence Variants and Transcription Factor Deregulation Synergize to Construct Pathogenic Regulatory Circuits in B Cell Lymphoma
| PRJNA263570 | ENA
Project description:Human genetic variants are classified on the basis of potential pathogenicity to guide clinical decisions. However, mechanistic uncertainties often preclude definitive categorization. Germline coding and enhancer variants within the hematopoietic regulator GATA2 create a bone marrow failure and leukemia predisposition. The conserved murine enhancer promotes hematopoietic stem cell (HSC) genesis, and a single-nucleotide human variant in an Ets motif attenuates chemotherapy-induced hematopoietic regeneration. We describe “conditionally pathogenic” (CP) enhancer motif variants that differentially affect hematopoietic development and regeneration. The Ets motif variant functioned autonomously in hematopoietic cells to disrupt hematopoiesis. Because an epigenetically silenced normal allele can exacerbate phenotypes of a pathogenic heterozygous variant, we engineered a bone marrow failure model harboring the Ets motif variant and a severe enhancer mutation on the second allele. Despite normal developmental hematopoiesis, regeneration in response to chemotherapy, inflammation, and a therapeutic HSC mobilizer was compromised. The CP paradigm informs mechanisms underlying phenotypic plasticity and clinical genetics.
| S-EPMC8664263 | biostudies-literature
Project description:Mutations in enhancer-associated chromatin-modifying components and genomic alterations in non-coding regions of the genome occur frequently in cancer, and other diseases pointing to the importance of enhancer fidelity to ensure proper tissue homeostasis. In this review, I will use specific examples to discuss how mutations in chromatin-modifying factors might affect enhancer activity of disease-relevant genes. I will then consider direct evidence from single nucleotide polymorphisms, small insertions, or deletions but also larger genomic rearrangements such as duplications, deletions, translocations, and inversions of specific enhancers to demonstrate how they have the ability to impact enhancer activity of disease genes including oncogenes and tumor suppressor genes. Considering that the scientific community only fairly recently has begun to focus its attention on "enhancer malfunction" in disease, I propose that multiple new enhancer-regulated and disease-relevant processes will be uncovered in the near future that will constitute the mechanistic basis for novel therapeutic avenues.
| S-EPMC5160997 | biostudies-other
Project description:BackgroundPulmonary arterial hypertension (PAH) is a rare disease characterized by remodeling of the pulmonary arteries, increased vascular resistance, and right-sided heart failure. Genome-wide association studies of idiopathic/heritable PAH established novel genetic risk variants, including conserved enhancers upstream of transcription factor (TF) SOX17 containing 2 independent signals. SOX17 is an important TF in embryonic development and in the homeostasis of pulmonary artery endothelial cells (hPAEC) in the adult. Rare pathogenic mutations in SOX17 cause heritable PAH. We hypothesized that PAH risk alleles in an enhancer region impair TF-binding upstream of SOX17, which in turn reduces SOX17 expression and contributes to disturbed endothelial cell function and PAH development.MethodsCRISPR manipulation and siRNA were used to modulate SOX17 expression. Electromobility shift assays were used to confirm in silico-predicted TF differential binding to the SOX17 variants. Functional assays in hPAECs were used to establish the biological consequences of SOX17 loss. In silico analysis with the connectivity map was used to predict compounds that rescue disturbed SOX17 signaling. Mice with deletion of the SOX17-signal 1 enhancer region (SOX17-4593/enhKO) were phenotyped in response to chronic hypoxia and SU5416/hypoxia.ResultsCRISPR inhibition of SOX17-signal 2 and deletion of SOX17-signal 1 specifically decreased SOX17 expression. Electromobility shift assays demonstrated differential binding of hPAEC nuclear proteins to the risk and nonrisk alleles from both SOX17 signals. Candidate TFs HOXA5 and ROR-α were identified through in silico analysis and antibody electromobility shift assays. Analysis of the hPAEC transcriptomes revealed alteration of PAH-relevant pathways on SOX17 silencing, including extracellular matrix regulation. SOX17 silencing in hPAECs resulted in increased apoptosis, proliferation, and disturbance of barrier function. With the use of the connectivity map, compounds were identified that reversed the SOX17-dysfunction transcriptomic signatures in hPAECs. SOX17 enhancer knockout in mice reduced lung SOX17 expression, resulting in more severe pulmonary vascular leak and hypoxia or SU5416/hypoxia-induced pulmonary hypertension.ConclusionsCommon PAH risk variants upstream of the SOX17 promoter reduce endothelial SOX17 expression, at least in part, through differential binding of HOXA5 and ROR-α. Reduced SOX17 expression results in disturbed hPAEC function and PAH. Existing drug compounds can reverse the disturbed SOX17 pulmonary endothelial transcriptomic signature.
| S-EPMC7614572 | biostudies-literature