Project description:Super-enhancer (SE) plays a vital role in the determination of cell identity and cell fate through the control of cell- or tissue-specific gene regulation. Upregulated expression of coding genes is frequently associated with SE. However, the transcription dysregulation driven by SE, from long non-coding RNAs (lncRNAs) viewpoint, remains unclear. Here, SE-associated lncRNAs in HCC were comprehensively screened.
Project description:Super-enhancer (SE) plays a vital role in the determination of cell identity and cell fate through the control of cell- or tissue-specific gene regulation. Upregulated expression of coding genes is frequently associated with SE. However, the transcription dysregulation driven by SE, from long non-coding RNAs (lncRNAs) viewpoint, remains unclear. Here, SE-associated lncRNAs in HCC were comprehensively screened. The result shows that pol2-mediated transcription of SE-associated lncRNAs is more sensitive to JQ1 treatment in a genome-wide manner.
Project description:Here we apply integrated epigenomic and transcriptomic profiling to uncover super-enhancer heterogeneity between breast cancer subtypes, and provide clinically relevant biological insights towards TNBC. Using CRISPR/Cas9-mediated gene editing, we identify genes that are specifically regulated by TNBC-specific super-enhancers, including FOXC1 and MET, thereby unveiling a mechanism for specific overexpression of the key oncogenes in TNBC. We also identify ANLN as a novel TNBC-specific gene regulated by super-enhancer. Our studies reveal a TNBC-specific epigenomic landscape, contributing to the dysregulated oncogene expression in breast tumorigenesis.
Project description:A large “gene desert” located far upstream from Fshb and Kcna4 contains several gonadotrope-specific accessible chromatin sites which, in chromatin conformation capture (3C), were seen to make distinct contacts with both genes. The region displays several features of a super-enhancer and both genes were strongly suppressed by JQ-1, which represses super-enhancer activity. The sites of open chromatin were seen, in chromatin immunoprecipitation (ChIP), to bind Brd4 and Med1, most notably at a site located -67 kb from the Fshb gene, as well as binding Ctcf further upstream (at -123 kbp), all of which were increased following activin exposure. The locus is also transcribed to chromatin-associated lncRNAs whose levels correlate with Fshb and Kcna4 mRNA levels in vivo and in cultured gonadotrope cells, indicating coordinated regulation. CRISPR interference (CRISPRi) confirmed distinct functions for each of the elements on these genes and, together with the 3C data, indicate that the -67 kb locus mediates specifically both basal and activin-stimulated Fshb expression, while the site at -59 kb contributes to activin-stimulation of both genes. Single-cell multiomics showed that the -67 kb element is accessible in pituitary stem cells and during gonadotrope differentiation, preceding opening of the Fshb promoter, although it is closed in other differentiated cell types. Foxl2 was found to bind this element and contributes to maintaining its chromatin accessibility, seemingly by recruiting Supt16H, a component of the FACT complex, with which it interacts. These findings define a distal, activin-responsive super-enhancer that regulates Fshb transcription and shapes the gonadotrope regulatory landscape.