Project description:We report the application of circular chromatin conformation capture (4C) sequencing technology for master transcription factor (KLF5 and ELF3) in human esophageal adenocarcinoma cancer cell lines (ESO26) . By baiting the promoters of KLF5 and ELF3, we esatblished the interaction with unknown enhnacer marks.
Project description:We profiled fresh-frozen esophageal tumor and normal samples and cell lines with chromatin immunoprecipitation sequencing (ChIP-Seq). Mathematically modeling was performed to establish (super)-enhancers landscapes and inter-connected transcriptional circuitry formed by master TFs. Coregulation and cooperation between master TFs was investigated by ChIP-Seq, RNASeq, 4C-Seq and luciferase assay. Biological functions of candidate factors were evaluated by measuring cell proliferation, colony formation, cell apoptosis and xenograft growth.
Project description:Master transcription factors form interconnected circuitry and orchestrate transcriptional networks in esophageal adenocarcinoma [ChIP-Seq]
Project description:We mapped the transcriptional regulatory circuitry for six master regulators in human hepatocytes using chromatin immunoprecipitation and high-resolution promoter microarrays. The results show that these regulators form a highly interconnected core circuitry, and reveal the local regulatory network motifs created by regulator-gene interactions. Auto-regulation was a prominent theme among these regulators. We found that hepatocyte master regulators tend to bind promoter regions combinatorially and that the number of transcription factors bound to a promoter corresponds with observed gene expression. Our studies reveal portions of the core circuitry of human hepatocytes.
Project description:Enhancer looping governs gene regulatory circuitry but is challenging to detect. Here we present Tri-4C, an ultrafine mapping method for distal chromatin contacts using triple restriction enzyme (RE) digestion. Tri-4C identifies enhancer loops that are undetectable by current single RE- based methods and reveals quantitative loop strengths in enhancer interaction networks underlying dynamic gene control. This multi-RE approach may be applied to general 3C-derived methods for accurate detection of enhancer loops.
Project description:Enhancer looping governs gene regulatory circuitry but is challenging to detect. Here we present Tri-4C, an ultrafine mapping method for distal chromatin contacts using triple restriction enzyme (RE) digestion. Tri-4C identifies enhancer loops that are undetectable by current single RE- based methods and reveals quantitative loop strengths in enhancer interaction networks underlying dynamic gene control. This multi-RE approach may be applied to general 3C-derived methods for accurate detection of enhancer loops.
Project description:Tremendous progress has been made in identifying individual transcription factors that regulate hematopoietic differentiation, but many aspects of the global architecture of hematopoiesis remain unknown. Here, we profiled gene expression in 38 distinct purified populations of human hematopoietic cells and used probabilistic models of gene expression patterns and sequence-based analysis of motifs in gene promoters to decipher the general organization of their regulatory circuitry. We identified modules of highly co-expressed genes, some of which are restricted to a single lineage, but most are expressed at variable levels across multiple lineages. We found densely interconnected cis-regulatory circuits and a large number of transcription factors that are differentially expressed across hematopoietic states, suggesting a more complex regulatory system than previously assumed. We functionally validated a subset of candidate factors using RNA interference and ChIP-Seq. Our dataset, analytic tools, and findings, available on a web-based portal, provide a unique resource to study the regulatory architecture of hematopoiesis. We defined 38 distinct hematopoietic cell states based on cell surface marker expression, representing hematopoietic stem and progenitor cells, terminally differentiated cells, and intermediate states. For each state, we purified samples separately from 4 to 7 independent donors by multiparameter flow cytometry, yielding 211 profiled samples. Cells from all stem and progenitor populations were purified from umbilical cord blood. Terminally differentiated lymphocyte populations were purified from peripheral blood.