Biology subjects

Corcoran, A.

Publications and source records attributed to Corcoran, A..

2 recordsLinked to original sources

bioRxiv2020

Epigenomic translocation of H3K4me3 broad domains following super-enhancer hijacking

Chromosomal translocations are important drivers of haematological malignancies whereby proto-oncogenes are activated by juxtaposition with enhancers, often called enhancer hijacking. We analysed the epigenomic consequences of rearrangements between the super-enhancers of the immunoglobulin heavy 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 its gene body. We observed similar cancer-specific H3K4me3-BDs associated with hijacking of super-enhancers of other common oncogenes in B-cell (MAF, MYC and FGFR3/NSD2) and T-cell malignancies (LMO2, TLX3 and TAL1). Our analysis suggests that H3K4me3-BDs can be created by super-enhancers and supports the new concept of epigenomic translocation, where the relocation of H3K4me3-BDs from cell identity genes to oncogenes accompanies the translocation of super-enhancers.

genomics↗

bioRxiv2019

Network analysis of promoter interactions reveals the hierarchical differences in genome organisation between human pluripotent states

SO_SCPCAPUMMARYC_SCPCAPA complex and poorly understood interplay between 3D genome organisation, transcription factors and chromatin state underpins cell identity. To gain a systems-level understanding of this interplay, we generated a high-resolution atlas of annotated chromatin interactions in naive and primed human pluripotent stem cells and developed a network-graph approach to examine the atlas at multiple spatial scales. Investigating chromatin interactions as a network uncovered highly connected hubs that changed substantially in interaction frequency and in transcriptional co-regulation between pluripotent states. Small hubs frequently merged to form larger networks in primed cells, often linked by newly-formed Polycomb-associated interactions. Importantly, we identified state-specific differences in enhancer activity and interactivity that corresponded with widespread reconfiguration of transcription factor binding and target gene expression. These findings provide multilayered insights into the gene regulatory control of human pluripotency and our systems-based network approach could be applied broadly to uncover new principles of 3D genome organisation.

genomics↗