The methyl-cytosine binding protein 2 (MeCP2) is a reader of epigenetic DNA methylation marks and necessary and sufficient to reorganize 3D heterochromatin structure during cellular differentiation, e.g., myogenesis. In addition to global expression profile changes, myogenic differentiation is accompanied by 3D-heterochromatin reorganization that is dependent on MeCP2. MeCP2 is enriched at pericentric heterochromatin foci (chromocenters). During myogenesis, the total heterochromatin foci number per nucleus decreases while foci volumes and MeCP2 protein levels increase. Ectopic MeCP2 is able to mimic similar heterochromatin restructuring in the absence of differentiation.
Gene repositioning within the cell nucleus is not random and is determined by its genomic neighborhood.
Specimen part, Cell line
View SamplesThe transcriptional response to many widely used drugs and its modulation by genetic variability is poorly understood. Here we present an analysis of RNAseq profiles from heart tissue of 18 inbred mouse strains treated with the ß-blocker atenolol (ATE) and the ß-agonist isoproterenol (ISO). Differential expression analyses revealed a large set of genes responding to ISO (n=1770 at FDR=0.0001) and a comparatively small one responding to ATE (n=23 at FDR=0.0001). At a less stringent definition of differential expression, the transcriptional responses to these two antagonistic drugs are reciprocal for many genes, with an overall anti-correlation of r= -0.3. This trend is also observed at the level of most individual strains even though the power to detect differential expression is significantly reduced. The inversely expressed gene sets are enriched with genes annotated for heart-related functions. Modular analysis revealed gene sets that exhibited coherent transcription profiles across some strains and/or treatments. Correlations between such modules and a broad spectrum of cardiovascular traits are stronger than expected by chance. This provides evidence for the overall importance of transcriptional regulation for these organismal responses and explicits links between co-expressed genes and the traits they are associated with. Gene set enrichment analysis of differentially expressed groups of genes pointed to pathways related to heart development and functionality. Our study provides new insights into the transcriptional response of the heart to perturbations of the ß-adrenergic system, implicating several new genes that had not been associated to this system previously. Overall design: Cardiac mRNA expression profiles of the various inbred mouse strains were examined either under baseline condition (control) or in response to chronic administration of isoproterenol or atenolol at 10 mg/kg per day for 2 weeks. Expression data were produced by RNA-sequencing, in triplicates, using the HiSeq 2000 Illumina platform. Only males, aged ten to twelve weeks on average, were included in the experimental protocol. Mouse ID numbers refer to those described in Berthonneche C. et al. PLoS One. 2009 Aug 12;4(8):e6610 (doi: 10.1371/journal.pone.0006610. PMID: 19672458). Corresponding individual phenotypic values, in particular heart rate, systolic blood pressure, electrocardiogaphic measurements and heart weight are available in dataset "maurer1" of the Mouse Phenome Database (http://phenome.jax.org/). Preparation of the sequencing libraries, RNA-sequencing and RNA expression quantitations were performed by the BGI.
RNAseq analysis of heart tissue from mice treated with atenolol and isoproterenol reveals a reciprocal transcriptional response.
Sex, Specimen part, Treatment, Subject
View SamplesBackground: The prognostic value of histologic grade (HG) in invasive lobular carcinoma (ILC) remains uncertain, and most ILC tumors are graded as HG2. Genomic grade (GG) is a 97-gene signature that improves the prognostic value of HG. This study evaluates whether GG may overcome the limitations of HG in ILC.
Genomic grade adds prognostic value in invasive lobular carcinoma.
Sex, Specimen part, Disease, Disease stage
View SamplesWe used Au nanoparticles (Au-NPs) as a model for studying particle specific effects of manufactured nanomaterials (MNMs) by examining the toxicogenomic responses in a model soil organism, free living nematode Caenorhabditis elegans. Global genome expression for nematodes exposed to 4-nm citrate-coated Au-NPs at the LC10 (5.9 mg L-1) revealed significant differential expression of 797 genes. The levels of expression for five genes (apl-1, dyn-1, act-5, abu-11, and hsp-4) were confirmed independently with qRT-PCR. Seven common biological pathways associated with 38 of these genes were identified. Activation of 26 pqn/abu genes from noncanonical Unfolded Protein Response (UPR) pathway and up-regulation of molecular chaperones (hsp-16.1, hsp-70, hsp-3 and hsp-4) were observed and are likely indicative of endoplasmic reticulum stress. Inhibition of abu-11 with RNAi showed increase in mortality in Au-NP exposed nematodes suggesting possible involvement of abu-11 (a gene associated with specific to C. elegans UPR) in a protective mechanism against Au-NPs. Exposure to Au-NPs also caused activation of genes involved in apoptosis and necrosis and resulted ultimately in 10% mortality. These results demonstrate that Au-NPs are bioavailable and cause adverse effects to a model ecoreceptor which activate both general and specific biological pathways.
Toxicogenomic responses of the model organism Caenorhabditis elegans to gold nanoparticles.
Treatment
View SamplesECRG4 is a promising tumor suppressor gene (TSG) recently identified in esophageal carcinoma. Its expression and prognostic value have never been explored in breast cancer. Using DNA microarray, we examined ECRG4 mRNA expression in 353 invasive breast cancer samples. A meta-analysis was performed on a large public retrospective gene expression dataset (n=1,387) to analyze correlation between ECRG4 expression and histo-clinical features including survival.
Down-regulation of ECRG4, a candidate tumor suppressor gene, in human breast cancer.
Age, Specimen part
View SamplesMetastasis is a complex process involving loss of adhesion, migration, invasion and proliferation of cancer cells. Cell adhesion molecules play a pivotal role in this phenomenon by regulating cell-cell and cell-matrix interactions. CD146 (MCAM) is associated with advanced tumor stage in melanoma, prostate and ovarian cancers.
CD146 expression is associated with a poor prognosis in human breast tumors and with enhanced motility in breast cancer cell lines.
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View SamplesPediatric Acute Myeloid Leukemia (AML) is an aggressive and poor prognosis malignancy for which there are few effective targeted approaches, despite the numerous genetic alterations, including MLL gene rearrangements (MLL-r). The histone methyltransferase DOT1L is involved in supporting proliferation of MLL-r cells, for which a target inhibitor, Pinometostat, has been evaluated in a clinical trial recruiting pediatric MLL-r leukemic patients. However, modest clinical effects have been reported. Recent studies reported that additional leukemia subtypes lacking MLL-r are sensitive to DOT1L inhibition. Here we report that targeting DOT1L with Pinometostat sensitizes pediatric AML cells to further treatment with the multi-kinase inhibitor Sorafenib, irrespectively of MLL-r. DOT1L pharmacologic inhibition induces AML cell differentiation and modulated expression of genes with relevant roles in cancer development. Such modifications in transcriptional program impact on further treatments, inducing a strong sensitization to Sorafenib, with increased apoptosis and growth suppression of both AML cell lines and primary pediatric AML cells with diverse genotypes. We used microarrays to define differential regulation of gene expression in AML cell lines with or without MLL gene rearrangements following pharmacologic inhibition of DOT1L.
Inhibition of Methyltransferase DOT1L Sensitizes to Sorafenib Treatment AML Cells Irrespective of <i>MLL</i>-Rearrangements: A Novel Therapeutic Strategy for Pediatric AML.
Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Depletion of DNMT1 in differentiated human cells highlights key classes of sensitive genes and an interplay with polycomb repression.
Sex, Specimen part, Time
View SamplesDNA methylation plays a vital role in the cell, but loss-of-function mutations of the maintenance methyltransferase DNMT1 in normal human cells are lethal, precluding target identification, and existing hypomorphic lines are tumour cells. We generated instead a hypomorphic series in normal hTERT-immortalised fibroblasts using stably integrated short hairpin RNA. Approx 2/3 of sites showed demethylation as expected, with 1/3 showing hypermethylation, and targets were shared between the three independently-derived lines. Enrichment analysis indicated significant losses at promoters and gene bodies with four gene classes most affected: 1)protocadherins, which are key to neural cell identity; 2)genes involved in fat homeostasis/body mass determination; 3)olfactory receptors and 4) cancer/testis antigen (CTA) genes. Overall effects on transcription were relatively small in these fibroblasts, but CTA genes showed robust derepression. Comparison with siRNA-treated cells indicated that shRNA lines show substantial remethylation over time. Regions showing persistent hypomethylation in the shRNA lines were associated with polycomb repression, and were derepressed on addition of an EZH2 inhibitor. Persistent hypermethylation in shRNA lines was in contrast associated with poised promoters. Our results suggest polycomb marking blocks remethylation and indicate the sensitivity of key neural, adipose, and cancer-associated genes to chronic depletion of maintenance methylation activity.
Depletion of DNMT1 in differentiated human cells highlights key classes of sensitive genes and an interplay with polycomb repression.
Sex, Specimen part, Time
View SamplesPurpose:To take a comprehensive effort in characterizing the brain vasculature gene expression upon hyperglycemia. Methods: We extracted mRNA from brain microvasculature fragments isolated from a genetic mouse model of hyperglycemia (Ins2-AKITA) and WT mice and analyzed their transcriptome with RNA sequencing The samples were sequenced on an Illumina HiSeq 2500 sequencer at the SNP&SEQ sequencing facility (Science for Life laboratory (SciLifeLab), Uppsala sequencing node). The reads were aligned to the Ensembl mouse gene assembly (NCBIM37) using Tophat2 software (version 2.0.4). The duplicated reads were removed using the picard tool (version 1.92). To identify the genes significantly enriched in the pericyte samples as compared with microvascular samples, statistical tests were performed using the Cufflinks tool (version 2.2.1) Results: Twenty-three genes were significantly regulated in mutant when compared to WT (False Discovery Rate < 0.05) Overall design: The microvascular RNA from two male heterozygous Ins2-AKITA mice and three littermate wild-type controls were processed and sequenced on the Illumina HiSeq 2500 platform in the sequencing facility in Uppsala University.
Prolonged systemic hyperglycemia does not cause pericyte loss and permeability at the mouse blood-brain barrier.
Sex, Specimen part, Subject
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