The effect of drugs, disease and other perturbations on mRNA levels are studied using gene expression microarrays or RNA-seq, with the goal of understanding molecular effects arising from the perturbation. Previous comparisons of reproducibility across laboratories have been limited in scale and focused on a single model. The use of model systems, such as cultured primary cells or cancer cell lines, assumes that mechanistic insights derived with would have been observed via in vivo studies. We examined the concordance of compound-induced transcriptional changes using data from several sources: rat liver and rat primary hepatocytes (RPH) from Drug Matrix (DM) and open TG-GATEs (TG), primary human hepatocytes (HPH) from TG, and mouse liver / HepG2 results from the Gene Expression Omnibus (GEO) repository. Gene expression changes for treatments were normalized to controls and analyzed with three methods: 1) gene level for 9071 high expression genes in rat liver, 2) gene set analysis (GSA) using canonical pathways and gene ontology sets, 3) weighted gene co-expression network analysis (WGCNA). Co-expression networks performed better than genes or GSA on a quantitative metric when comparing treatment effects within rat liver and rat vs. mouse liver. Genes and modules performed similarly at Connectivity Map-style analyses, where success at identifying similar treatments among a collection of reference profiles is the goal. Comparisons between rat liver and RPH, and those between RPH, HPH and HepG2 cells reveal low concordance for all methods. We investigate differences in the baseline state of cultured cells in the context of drug-induced perturbations in rat liver and highlight the striking similarity between toxicant-exposed cells in vivo and untreated cells in vitro.
Assessing Concordance of Drug-Induced Transcriptional Response in Rodent Liver and Cultured Hepatocytes.
Sex, Specimen part
View SamplesChronic alcohol consumption can lead to alchohol-related brain damage (ARBD). Despite the well known acute effects of alcohol the mechanism responsible for chronic brain damage is largely unknown. Pathologically the major change is the loss of white matter while neuronal loss is mild and restricted to a few areas such as the prefrontal cortex. In order to improve our understanding of ARBD pathogenesis we used microarrays to explore the white matter transcriptome of alcoholics and controls.
Comorbidities, confounders, and the white matter transcriptome in chronic alcoholism.
Specimen part, Disease, Disease stage
View SamplesMouse lung epithelial subpopulations (alveolar type 2, basal and airway luminal cells) freshly dissociated from mouse lung and trachea were isolated by FACS. RNA-seq gene expression profiling was used to determine gene signature from each population. Overall design: Cells were isolated from the small airway (SA) and large airway (LA) of 6 mouse lungs
Lung Basal Stem Cells Rapidly Repair DNA Damage Using the Error-Prone Nonhomologous End-Joining Pathway.
Specimen part, Cell line, Subject
View SamplesDespite investment in toxicogenomics, nonclinical safety studies are still used to predict clinical liabilities for new drug candidates. Network-based approaches for genomic analysis help overcome challenges with whole-genome transcriptional profiling using limited numbers of treatments for phenotypes of interest. Herein, we apply co-expression network analysis to safety assessment using rat liver gene expression data to define 415 modules, exhibiting unique transcriptional control, organized in a visual representation of the transcriptome (the TXG-MAP). Accounting for the overall transcriptional activity resulting from treatment, we explain mechanisms of toxicity and predict distinct toxicity phenotypes using module associations. We demonstrate that early network responses compliment traditional histology-based assessment in predicting outcomes for longer studies and identify a novel mechanism of hepatotoxicity involving endoplasmic reticulum stress and Nrf2 activation. Module-based molecular subtypes of cholestatic injury derived using rat translate to human. Moreover, compared to gene-level analysis alone, combining module and gene-level analysis performed in sequence identifies significantly more phenotype-gene associations, including established and novel biomarkers of liver injury.
Toxicogenomic module associations with pathogenesis: a network-based approach to understanding drug toxicity.
Sex, Specimen part
View SamplesWe report the differences in gene expression between wild type and Tgif1;Tgif2 double null mouse embryos at approximately 9.0 days after fertilization. Overall design: Stage matched individual mouse embryos at approximately 9.0 days after fertilization (~9-10 somites) were analyzed by RNA-seq. We analyzed four wild type embryos and eight conditional double mutant embryos, lacking both alleles of Tgif1 and both Tgif2 alleles.
Tgif1 and Tgif2 Repress Expression of the RabGAP Evi5l.
Age, Specimen part, Subject
View SamplesMicroRNAs (miRNAs) are short noncoding RNA molecules regulating the expression of mRNAs. Target identification of miRNAs is computationally difficult due to the relatively low homology between miRNAs and their targets. We provide data here utilizing an experimental approach to identify targets of mmu-miR-378-3p, where mmu-miR-378-3p was overexpressed and silenced in NIH-3T3 murine fibroblasts and compared to control RNA transfected cells (RISC-free siRNA). Expression of mRNAs was profiled and differentially expressed genes following either treatment as compared to control transfected cells were identified. In this way we identified 491 significantly differentially expressed genes with more than 1.4 fold change in either comparison. One of the putative targets Akt-1 was subsequently confirmed by luciferase reporter assay.
Induction of IL-4Rα-dependent microRNAs identifies PI3K/Akt signaling as essential for IL-4-driven murine macrophage proliferation in vivo.
Specimen part, Cell line
View SamplesSquamous cell carcinoma (SCC) of lung is a devastating malignancy with no effective treatments, due to its complex genomic profile. Therefore, pre-clinical models mimicking its salient features are urgently needed. Here we describe mouse models bearing various combinations of genetic lesions predominantly found in human SCC. We show that Sox2 but not Fgfr1 overexpression in tracheobronchial basal cells combined with Cdkn2ab and Pten loss results in SCC closely resembling the human counterpart. Interestingly, Sox2;Pten;Cdkn2ab mice develop SCC with a more peripheral location when Club or Alveolar type 2 (AT2) cells are targeted. Our model highlights the essential role of Sox2 in promoting a squamous cell fate from different cells-of-origin and represents an invaluable tool for the developing better intervention strategies. Overall design: After RNA extraction and Bioanalyzer analysis, we processed samples with high quality RNA profiles using Illumina Hiseq2500.
SOX2 Is the Determining Oncogenic Switch in Promoting Lung Squamous Cell Carcinoma from Different Cells of Origin.
Specimen part, Disease, Disease stage, Subject
View SamplesZinc finger nucleases (ZFN) are powerful tools for editing genes in cells. Here we use ZFNs to interrogate the biological function of human ADPGK, which encodes an ADP-dependent glucokinase (ADPGK), in tumour cell lines. The hypothesis tested is that ADPGK utilises ADP to phosphorylate glucose under conditions where ATP becomes limiting, such as hypoxia. We characterised two ZFN knockout clones in each of two tumour cell lines (H460 and HCT116). All four lines had frameshift mutations in all alleles at the target site in exon 1 of ADPGK, and were ADPGK-null by immunoblotting. ADPGK knockout had little or no effect on cell proliferation, but compromised the ability of H460 cells to survive siRNA silencing of hexokinase-2 under oxic conditions, with clonogenic survival falling from 213% for the parental line to 6.40.8% (p=0.002) and 4.30.8% (p=0.001) for the two knockouts. A similar increased sensitivity to clonogenic cell killing was observed under anoxia. No such changes were found when ADPGK was knocked out in HCT116 cells, for which the parental line was less sensitive than H460 to anoxia and to hexokinase-2 silencing. While knockout of ADPGK in HCT116 cells caused few changes in global gene expression, knockout of ADPGK in H460 cells caused notable up-regulation of mRNAs encoding cell adhesion proteins. Surprisingly, we could discern no effect on glycolysis as measured by glucose consumption or lactate formation under oxic or anoxic conditions, or extracellular acidification rate (Seahorse XF analyser) under oxic conditions in a variety of media. However, oxygen consumption rates were generally lower in the ADPGK knockouts, in some cases markedly so. Collectively, the results demonstrate that ADPGK can contribute to tumour cell survival under conditions of high glycolytic dependence, but the phenotype resulting from knockout of ADPGK is cell line dependent and appears to be unrelated to priming of glycolysis.
Expression and role in glycolysis of human ADP-dependent glucokinase.
Cell line
View SamplesEpithelial (CD31-CD45-EpCAM+) cells were isolated by FACS from Grhl2-deficient (Shh-Cre;Grhl2f/-) and control (Shh-Cre;Grhl2f/+) embryonic lungs at day E16.5 (3 biological replicates/genotype). Total RNA extracted from the samples was subjected to next-generation sequencing (NGS) library preparation using standard Illumina protocols. Completed libraries from individual samples were sequenced on a HiSeq2500 at the Australian Genome Research Facility. Overall design: RNA-seq was performed on Grhl2-deficient and control epithelium isolated from the lungs of E16.5 embryos (n=3 replicates/genotype/cell population).
Lung morphogenesis is orchestrated through Grainyhead-like 2 (Grhl2) transcriptional programs.
Sex, Specimen part, Subject
View SamplesWhereas DNA methylation is essential for genomic imprinting, the importance of histone methylation in the allelic repression of imprinted genes is unclear. Imprinting control regions (ICRs), however, are consistently marked by histone H3 K9 methylation on their DNA-methylated allele. In the placenta, the paternal silencing along the Kcnq1 domain on distal chromosome 7 also correlates with the presence of H3-K9 methylation, but imprinted repression at these genes is maintained independently of DNA methylation. To explore which histone methyltransferase (HMT) could mediate the allelic H3-K9 methylation on distal chromosome 7, and at ICRs, we generated mouse conceptuses deficient for the SET-domain protein G9a. We find that in the embryo and placenta, the differential DNA methylation at ICRs and imprinted genes is maintained in the absence of G9a. Accordingly, in embryos, imprinted gene expression is unchanged at the domains analysed, in spite of a global loss of H3-K9 di-methylation (H3K9me2). In contrast, the placenta-specific imprinting of genes on distal chromosome 7 is lost in the absence of G9, and this correlates with a loss of H3K9me2 and H3K9me3. These findings provide the first in vivo evidence for the involvement of a SET domain protein in imprinting and highlight the importance of histone lysine methylation rather than DNA methylation in the maintenance of imprinting in the trophoblast lineage.
G9a histone methyltransferase contributes to imprinting in the mouse placenta.
Age, Specimen part
View Samples