During normal or pathological epithelial-to-mesenchymal transition, epithelium-specific gene expression is shut down, with the DNA-binding factor ZEB1 acting as a master suppressor of epithelial identity. Here, we show that ZEB1 occupies primate-specific tandem repeats (TRs) harboring dozens of copies of its DNA-binding motif and located within genomic loci relevant for epithelial identity. Deletion of one such repeat in a quasi-mesenchymal human cancer cell line induced the reacquisition of epithelial features and phenocopied the effects of ZEB1 gene deletion. Since ZEB1 binds clustered motifs in a non-cooperative manner, changes in its nuclear concentration enable graded adjustments of TR occupancy, thus fine-tuning repression level. In addition, high motif density in TRs allows ZEB1 binding (and shutdown of epithelial programs) despite differences in chromatin organization and accessibility among epithelial cell types. Overall design: Total RNA from human pancreatic ductal adenocarcinoma cell lines was processed for multiparallel sequencing. Experiments were carried out in genome edited clonal MiaPaCa2 cells (3 ZEB1-deleted CRISPR-Cas9 clones and 3 wt clones).
Co-optation of Tandem DNA Repeats for the Maintenance of Mesenchymal Identity.
Cell line, Subject
View SamplesWe found that the non-essential amino acid L-Proline (L-Pro) acts as a signaling molecule that promotes the conversion of embryonic stem cells (ESCs) into mesenchymal-like, spindle-shaped, highly motile, invasive pluripotent stem cells. This embryonic stem cell-to-mesenchymal-like transition (esMT) is accompanied by a genome-wide remodeling of the transcriptome
L-Proline induces a mesenchymal-like invasive program in embryonic stem cells by remodeling H3K9 and H3K36 methylation.
Cell line
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Integrated approaches to miRNAs target definition: time-series analysis in an osteosarcoma differentiative model.
Specimen part, Cell line, Time
View SamplesCellular responses to carcinogens are typically studied in transformed cell lines, which do not reflect the physiological status of normal tissues. To address this question, we have characterized the transcriptional program and cellular responses of normal human lung WI-38 fibroblasts upon exposure to the ultimate carcinogen benzo[a]pyrene diol epoxide (BPDE). Exposure to BPDE induces a strong inflammatory response in WI-38 primary fibroblasts. Whole-genome microarray analysis shows induction of several genes related to the production of inflammatory factors, including those that encode interleukins (ILs), growth factors, and enzymes related to prostaglandin synthesis and signaling. This is the first demonstration that a strong inflammatory response is triggered in primary fibroblasts in response to a reactive diol epoxide derived from a polycyclic aromatic hydrocarbon.
Benzo[a]pyrene diol epoxide stimulates an inflammatory response in normal human lung fibroblasts through a p53 and JNK mediated pathway.
Specimen part
View SamplesWe explored the transcriptional modification induced by CD99 transfection in the osteosarcoma cell lines SaOS-2 after 0, 7 and 14 days in differentiation medium.
Integrated approaches to miRNAs target definition: time-series analysis in an osteosarcoma differentiative model.
Specimen part, Cell line, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
IRF-8 extinguishes neutrophil production and promotes dendritic cell lineage commitment in both myeloid and lymphoid mouse progenitors.
Specimen part
View SamplesWhile most blood lineages are assumed to mature through a single cellular and developmental route downstream of hematopoietic stem cells (HSCs), dendritic cells (DCs) can be derived from both myeloid and lymphoid progenitors in vivo. To determine how distinct progenitors can generate similar downstream lineages, we examined the transcriptional changes that accompany loss of in vivo myeloid potential as common myeloid progenitors (CMPs) differentiate into common dendritic cell progenitors (CDPs), and as lymphoid-primed multipotent progenitors (LMPPs) differentiate into all lymphoid progenitors (ALPs). Microarray studies revealed that Interferon regulatory factor 8 (IRF-8) expression increased during each of these transitions. Competitive reconstitutions using Irf8-/- bone marrow demonstrated cell-intrinsic defects in the formation of CDPs and all splenic dendritic cell subsets. Irf8-/- CMPs and, unexpectedly, Irf8-/- ALPs produced more neutrophils in vivo than their wild type counterparts at the expense of DCs. Retroviral expression of IRF-8 in multiple progenitors led to reduced neutrophil production and increased numbers of DCs, even in the granulocyte-macrophage progenitor (GMP), which does not normally possess conventional DC potential. These data suggest that IRF-8 represses a neutrophil module of development and promotes convergent DC development from multiple lymphoid and myeloid progenitors autonomously of cellular context.
IRF-8 extinguishes neutrophil production and promotes dendritic cell lineage commitment in both myeloid and lymphoid mouse progenitors.
Specimen part
View SamplesCarbonyl chloride (phosgene) is a toxic industrial compound (TIC) widely used in industry for the production of synthetic products, such as polyfoam rubber, plastics, and dyes. Exposure to phosgene results in a latent (1-24 hr), potentially life-threatening pulmonary edema and irreversible acute lung injury. A genomic approach was utilized to investigate the molecular mechanism of phosgene-induced lung injury. CD-1 male mice were exposed whole-body to either air or a concentration x time (c x t) amount of 32 mg/m3 (8 ppm) phosgene for 20 min (640 mg x min/m3). Lung tissue was collected from air- or phosgene-exposed mice at 0.5, 1, 4, 8, 12, 24, 48, and 72 hr post-exposure. RNA was extracted from the lung and used as starting material for the probing of oligonucleotide microarrays to determine changes in gene expression following phosgene exposure. The data were analyzed using principal component analysis (PCA) to determine the greatest sources of data variability. A three-way analysis of variance (ANOVA) based on exposure, time, and sample was performed to identify the genes most significantly changed as a result of phosgene exposure. These genes were rank ordered by p-values and categorized based on molecular function and biological process. Some of the most significant changes in gene expression reflect changes in glutathione synthesis and redox regulation of the cell, including upregulation of glutathione S-transferase alpha-2, glutathione peroxidase 2, and glutamate-cysteine ligase, catalytic subunit (also known as -glutamyl cysteine synthetase). This is in agreement with previous observations describing changes in redox enzyme activity after phosgene exposure. We are also investigating other pathways that are responsive to phosgene exposure to identify mechanisms of toxicity and potential therapeutic targets.
Genomic analysis of murine pulmonary tissue following carbonyl chloride inhalation.
No sample metadata fields
View SamplesSulfur mustard (HD) is a vesicating agent that targets the eyes, skin, and lungs, producing skin burns, conjunctivitis, and compromised respiratory function.
Acute Gene Expression Profile of Lung Tissue Following Sulfur Mustard Inhalation Exposure in Large Anesthetized Swine.
Sex, Specimen part
View SamplesOverexpression of the AP-2 transcription factor in breast tumours has been identified as an independent predictor of poor outcome and failure of hormone therapy, even in ER positive, ErbB2 negative tumours; markers of a more favourable prognosis. To understand further the role of AP-2 in breast carcinoma, we have used an RNA interference and gene expression profiling strategy using the MCF-7 cell line as a model for ER positive, ErbB2 negative tumours with AP-2 overexpression.
AP-2gamma promotes proliferation in breast tumour cells by direct repression of the CDKN1A gene.
Cell line
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