Similar Datasets
Project description:We performed a CRISPR-based functional genetic screen targeting CTCF binding elements (CBEs) located in the vicinity of ERα-bound enhancers. The screen identified four functional CBEs whose targeting resulted in a marked negative effect on the proliferation of MCF-7 cells (ERα-positive cells) but no significant effect on MDA-MB-231 (ERα-negative cells) cells. Here, we carried out GRO-seq analysis on MCF-7 cells induced with an sgRNA vector targeting one of the hits detected by the screen: sgRNA_1118, as well as non-targeting sgRNA and sg1830 as control.
2019-11-01 | GSE124572 | GEO
Project description:We performed a CRISPR-based functional genetic screen targeting CTCF binding elements (CBEs) located in the vicinity of ERα-bound enhancers. The screen identified four functional CBEs whose targeting resulted in a marked negative effect on the proliferation of MCF-7 cells (ERα-positive cells) but no significant effect on MDA-MB-231 (ERα-negative cells) cells. We then carried out RNA-seq analysis on MCF-7 cells induced with sgRNA vectors targeting these four CBEs: sgRNA_1118, sgRNA_1659, sgRNA_680 and sgRNA_810, as well as non-targeting sgRNA as control.
2019-11-01 | GSE124573 | GEO
Project description:GRO-seq on MCF7 cells induced with sgRNA vectors targeting CTCF binding elements
| PRJNA512524 | ENA
Project description:RNA-Seq and GRO-seq on MCF7 cells induced with sgRNA vectors targeting CTCF binding elements
| PRJNA512518 | ENA
Project description:RNA-seq on MCF7 cells induced with sgRNA vectors targeting CTCF binding elements
| PRJNA512525 | ENA
Project description:Modifications to the global run-on and sequencing (GRO-seq) protocol that enrich for 5'-capped RNAs can be used to reveal active transcriptional regulatory elements (TREs) with high accuracy. Here, we introduce discriminative regulatory-element detection from GRO-seq (dREG), a sensitive machine learning method that uses support vector regression to identify active TREs from GRO-seq data without requiring cap-based enrichment (https://github.com/Danko-Lab/dREG/). This approach allows TREs to be assayed together with gene expression levels and other transcriptional features in a single experiment. Predicted TREs are more enriched for several marks of transcriptional activation—including expression quantitative trait loci, disease-associated polymorphisms, acetylated histone 3 lysine 27 (H3K27ac) and transcription factor binding—than those identified by alternative functional assays. Using dREG, we surveyed TREs in eight human cell types and provide new insights into global patterns of TRE function.
| S-EPMC4507281 | biostudies-literature
Project description:Immunoglobulin heavy chain (IgH) variable region exons are assembled from V(H), D and J(H) gene segments in developing B lymphocytes. Within the 2.7-megabase mouse Igh locus, V(D)J recombination is regulated to ensure specific and diverse antibody repertoires. Here we report in mice a key Igh V(D)J recombination regulatory region, termed intergenic control region 1 (IGCR1), which lies between the V(H) and D clusters. Functionally, IGCR1 uses CTCF looping/insulator factor-binding elements and, correspondingly, mediates Igh loops containing distant enhancers. IGCR1 promotes normal B-cell development and balances antibody repertoires by inhibiting transcription and rearrangement of D(H)-proximal V(H) gene segments and promoting rearrangement of distal V(H) segments. IGCR1 maintains ordered and lineage-specific V(H)(D)J(H) recombination by suppressing V(H) joining to D segments not joined to J(H) segments, and V(H) to DJ(H) joins in thymocytes, respectively. IGCR1 is also required for feedback regulation and allelic exclusion of proximal V(H)-to-DJ(H) recombination. Our studies elucidate a long-sought Igh V(D)J recombination control region and indicate a new role for the generally expressed CTCF protein.
| S-EPMC3342812 | biostudies-literature
Project description:RAG endonuclease initiates antibody heavy chain variable region exon assembly from V, D, and J segments within a chromosomal V(D)J recombination center (RC) by cleaving between paired gene segments and flanking recombination signal sequences (RSSs). The IGCR1 control region promotes DJH intermediate formation by isolating Ds, JHs, and RCs from upstream VHs in a chromatin loop anchored by CTCF-binding elements (CBEs). How VHs access the DJHRC for VH to DJH rearrangement was unknown. We report that CBEs immediately downstream of frequently rearranged VH-RSSs increase recombination potential of their associated VH far beyond that provided by RSSs alone. This CBE activity becomes particularly striking upon IGCR1 inactivation, which allows RAG, likely via loop extrusion, to linearly scan chromatin far upstream. VH-associated CBEs stabilize interactions of D-proximal VHs first encountered by the DJHRC during linear RAG scanning and thereby promote dominant rearrangement of these VHs by an unanticipated chromatin accessibility-enhancing CBE function.
| S-EPMC6026039 | biostudies-literature
Project description:CCCTC-binding factor (CTCF)-mediated stable topologically associating domains (TADs) play a critical role in constraining interactions of DNA elements that are located in neighboring TADs. CTCF plays an important role in regulating the spatial and temporal expression of HOX genes that control embryonic development, body patterning, hematopoiesis, and leukemogenesis. However, it remains largely unknown whether and how HOX loci associated CTCF boundaries regulate chromatin organization and HOX gene expression. In the current protocol, a specific sgRNA pooled library targeting all CTCF binding sites in the HOXA/B/C/D loci has been generated to examine the effects of disrupting CTCF-associated chromatin boundaries on TAD formation and HOX gene expression. Through CRISPR-Cas9 genetic screening, the CTCF binding site located between HOXA7/HOXA9 genes (CBS7/9) has been identified as a critical regulator of oncogenic chromatin domain, as well as being important for maintaining ectopic HOX gene expression patterns in MLL-rearranged acute myeloid leukemia (AML). Thus, this sgRNA library screening approach provides novel insights into CTCF mediated genome organization in specific gene loci and also provides a basis for the functional characterization of the annotated genetic regulatory elements, both coding and noncoding, during normal biological processes in the post-human genome project era.
| S-EPMC7607627 | biostudies-literature
Project description:The interplay between mitogenic and proinflammatory signaling pathways play key roles in determining the phenotypes and clinical outcomes of breast cancers. We have used global nuclear run-on coupled with deep sequencing to characterize the immediate transcriptional responses of MCF-7 breast cancer cells treated with estradiol, TNFα, or both. In addition, we have integrated these data with chromatin immunoprecipitation coupled with deep sequencing for estrogen receptor alpha (ERα), the pioneer factor FoxA1 and the p65 subunit of the NF-κB transcription factor. Our results indicate extensive transcriptional interplay between these two signaling pathways, which is observed for a number of classical mitogenic and proinflammatory protein-coding genes. In addition, GRO-seq has allowed us to capture the transcriptional crosstalk at the genomic locations encoding for long non-coding RNAs, a poorly characterized class of RNAs which have been shown to play important roles in cancer outcomes. The synergistic and antagonistic interplay between estrogen and TNFα signaling at the gene level is also evident in the patterns of ERα and NF-κB binding, which relocalize to new binding sites that are not occupied by either treatment alone. Interestingly, the chromatin accessibility of classical ERα binding sites is predetermined prior to estrogen treatment, whereas ERα binding sites gained upon co-treatment with TNFα require NF-κB and FoxA1 to promote chromatin accessibility de novo. Our data suggest that TNFα signaling recruits FoxA1 and NF-κB to latent ERα enhancer locations and directly impact ERα enhancer accessibility. Binding of ERα to latent enhancers upon co-treatment, results in increased enhancer transcription, target gene expression and altered cellular response. This provides a mechanistic framework for understanding the molecular basis for integration of mitogenic and proinflammatory signaling in breast cancer. Using GRO-seq and ChIP-seq (ER, FoxA1 and p65) to assay the molecular crosstalk of MCF-7 cells treated with E2, TNFα or both E2+TNFα.
| S-ECPF-GEOD-59531 | biostudies-other