Hepatic iron overload is a risk factor for progression of hepatocellular carcinoma (HCC), although the molecular mechanisms underlying this association have remained unclear. We now show that the iron-sensing ubiquitin ligase FBXL5 is previously unrecognized oncosuppressor in liver carcinogenesis in mice. Hepatocellular iron overload evoked by FBXL5 ablation gives rise to oxidative stress, tissue damage, inflammation and compensatory proliferation in hepatocytes and to consequent promotion of liver carcinogenesis induced by exposure to a chemical carcinogen. The tumor-promoting effect of FBXL5 deficiency in the liver is also operative in a model of virus-induced HCC. FBXL5-deficient mice thus constitute the first genetically engineered mouse model of liver carcinogenesis induced by iron overload. Dysregulation of FBXL5-mediated cellular iron homeostasis was also found to be associated with poor prognosis in human HCC, implicating FBXL5 plays a significant role in defense against hepatocarcinogenesis. Overall design: Total RNA was extracted from the nontumor and tumor tissue of an Alb-Cre/Fbxl5F/F male mouse (nontumor, n = 5; tumor, n = 5) or two littermate control Fbxl5F/F mice (nontumor, n = 6; tumor, n = 6) at 45 weeks of age.
Disruption of FBXL5-mediated cellular iron homeostasis promotes liver carcinogenesis.
Specimen part, Cell line, Subject
View SamplesThe development of trichomes (leaf hairs) from pluripotent epidermal cells in Arabidopsis provides a powerful system to investigate the regulatory motifs involved in plant cell differentiation. Genetic studies have revealed that a bHLH transcription factor, GL3, activates downstream genes required for trichome initiation by interacting with a R2R3-MYB protein, GL1. In order to investigate genome-wide regulatory functions of GL1 and GL3, we performed genome-wide expression analyses using GR inducible systems of GL1 and GL3.
A systems approach reveals regulatory circuitry for Arabidopsis trichome initiation by the GL3 and GL1 selectors.
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View SamplesThe development of trichomes (leaf hairs) from pluripotent epidermal cells in Arabidopsis provides a powerful system to investigate the regulatory motifs involved in plant cell differentiation. Genetic studies have revealed that a bHLH transcription factor, GL3, activates downstream genes required for trichome initiation by interacting with a R2R3-MYB protein, GL1. We have taken advantage of several mutants in the trichome developmental pathway and gene expression analyses to identify a set of genes expressed predominantly in Arabidopsis trichomes.
A systems approach reveals regulatory circuitry for Arabidopsis trichome initiation by the GL3 and GL1 selectors.
No sample metadata fields
View SamplesAlcoholism is a complex disorder determined by interactions between genetic and environmental risk factors. Drosophila represents a powerful model system to dissect the genetic architecture of alcohol sensitivity, as large numbers of flies can readily be reared in defined genetic backgrounds and under controlled environmental conditions. Furthermore, flies exposed to ethanol undergo physiological and behavioral changes that resemble human alcohol intoxication, including loss of postural control, sedation, and development of tolerance.
Phenotypic and transcriptional response to selection for alcohol sensitivity in Drosophila melanogaster.
No sample metadata fields
View SamplesInnate immune cells control acute eosinophilic lung inflammation induced by cystein proteases. Here we characterize the dynamic change of gene expression profile in basophils, natural helper cells and eosinophils during lung inflammation via cystein protease Overall design: Examination of mRNA levels in individual cell populations, basophils, natural helper cells and eosinophils of the lung from naïve mice and papain treated mice.
Basophil-derived interleukin-4 controls the function of natural helper cells, a member of ILC2s, in lung inflammation.
No sample metadata fields
View SamplesThe neural transcription factor SOX11 is overexpressed in aggressive lymphoid neoplasms mainly in mantle cell lymphoma (MCL), but its functional role in malignant B-cells is unknown. To identify target genes transcriptionally regulated by SOX11 in malignant lymphoid cells, we have used Gene Expression Profiling (GEP) after SOX11 silencing in MCL cell lines.
SOX11 regulates PAX5 expression and blocks terminal B-cell differentiation in aggressive mantle cell lymphoma.
Specimen part, Cell line
View SamplesInterstitial cells of Cajal (ICC) are electrical pacemakers and mediators of neuromuscular neurotransmission in the gastrointestinal tract. Gastrointestinal stromal tumors (GIST) arise within the ICC lineage due to activating KIT/PDGFRA mutations. In this study we developed a method for isolation of human ICC by immunolabeling and fluorescence-activated cell sorting (FACS). Briefly, human gastric musculature was dissociated and incubated with antibodies against CD45, FCER1A, CD11B, KIT, and CD34. ICC (defined as HP-KIT+CD34- cells), NOT ICC (defined as HP-KIT-CD34- cells), and hematopoietic (HP) cells (defined as HP+ cells) were isolated using FACS. Microarray was performed on ICC, NOT ICC, HP+ cells, and unfractionated gastric tunica muscularis. This study utilized micorarray for the phenotypic characterization of FACS-sorted human ICC, allowing comparison of ICC to other cells of the gastric musculature, including GIST.
Hedgehog pathway dysregulation contributes to the pathogenesis of human gastrointestinal stromal tumors via GLI-mediated activation of KIT expression.
Specimen part
View SamplesProper functioning of tissues requires cells to behave in uniform, well-organized ways. Conversely, many diseases involve increased cellular heterogeneity due to genetic and epigenetic alterations. Defining the mechanisms that counteract phenotypic variability is therefore critical to understand how tissues sustain homeostasis. Here, we carried out a single-cell resolution screen of zebrafish embryonic blood vessels upon mutagenesis of single microRNA (miRNA) genes and multi-gene miRNA families. We found that miRNA mutants exhibit a profound increase in cellular phenotypic variability of specific vascular traits. Genome-wide analysis of endothelial miRNA target genes identified antagonistic regulatory nodes of vascular growth and morphogenesis signaling that allow variable cell behaviors when derepressed. Remarkably, lack of such miRNA activity greatly sensitized the vascular system to microenvironmental changes induced by pharmacological stress. We uncover a previously unrecognized role of miRNAs as a widespread protective mechanism that limits variability in cellular phenotypes. This discovery marks an important advance in our comprehension of how miRNAs function in the physiology of higher organisms. Overall design: Analysis of differential genes expression in Zebrafish endothelial cells for 4 different developmental stages
MicroRNAs Establish Uniform Traits during the Architecture of Vertebrate Embryos.
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View SamplesTranslocator protein (TSPO), previously known as the peripheral benzodiazepine receptor is a protein of unclear function in the outer mitochondrial membrane. Using TSPO gene-deleted mice, we recently demonstrated that the dogma surrounding mammalian TSPO as a cholesterol transporter essential for steroid hormone production is highly inaccurate. TSPO global knockout mice are apparently healthy and do not have any deficits in steroid hormone production. We present whole transcriptome shotgun sequencing data comparing adrenal gene expression between Tspo floxed (Tspofl/fl) and Tspo knockout (Tspo-/-) mice.
Peripheral benzodiazepine receptor/translocator protein global knock-out mice are viable with no effects on steroid hormone biosynthesis.
No sample metadata fields
View SamplesA chromosomal translocation fusion gene product EWS-WT1 is the defining genetic event in Desmoplastic Small Round Cell Tumor (DSRCT), a rare but aggressive tumor with a high rate of mortality. EWS-WT1 oncogene acts as an aberrant transcription factor that drives tumorigenesis, but the mechanism by which EWS-WT1 causes tumorigenesis is not well understood. To delineate the oncogenic mechanisms, we generated the EWS-WT1 fusion in the mouse using a gene targeting (knock-in) approach, enabling physiologic expression of EWS-WT1 under the native Ews promoter. We derived mouse embryonic fibroblasts (MEFs) and performed genome-wide expression profiling to identify transcripts directly regulated by EWS-WT1. Remarkably, expression of EWS-WT1 led to a dramatic induction of many neuronal genes. Notably, a neural reprogramming factor, ASCL1 (achaete-scute complex-like 1), was highly induced by EWS-WT1 in MEFs and in primary DSRCT. Further analysis demonstrated that EWS-WT1 directly binds to the proximal promoter region of ASCL1 and activates its transcription through multiple WT1-responsive elements. Depletion of EWS-WT1 in a DSRCT cell line resulted in severe reduction in ASCL1 expression and cell viability. Remarkably, when stimulated with neuronal induction media, cells expressing EWS-WT1 expressed neural markers and generated neurite-like projections. These results demonstrate for the first time that EWS-WT1 activates neural gene expression and is capable of directing partial neuronal differentiation, likely via ASCL1. These findings suggest that stimulating DSRCT tumor cells with biological or chemical agents that promote neural differentiation might be a useful approach to develop novel therapeutics against this incurable disease.
EWS-WT1 oncoprotein activates neuronal reprogramming factor ASCL1 and promotes neural differentiation.
Specimen part, Time
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