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GSE49469
Mus musculus
9 Downloadable Samples
Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Oncolytic viruses exploit common molecular changes in cancer cells, which are not present in normal cells, to target and kill cancer cells. Ras transformation and defects in type I interferon (IFN)-mediated antiviral responses are known to be the major mechanisms underlying viral oncolysis. Previously, we demonstrated that oncogenic RAS/Mitogen-activated protein kinase kinase (Ras/MEK) activation suppresses the transcription of many IFN-inducible genes in human cancer cells, suggesting that Ras transformation underlies type I IFN defects in cancer cells. Here, we investigated how Ras/MEK downregulates IFN-induced transcription. By conducting promoter deletion analysis of IFN-inducible genes, namely guanylate-binding protein 2 and IFN gamma inducible protein 47 (Ifi47), we identified the IFN regulatory factor 1 (IRF1) binding site as the promoter region responsible for the regulation of transcription by MEK. MEK inhibition promoted transcription of the IFN-inducible genes in wild type mouse embryonic fibroblasts (MEFs), but not in IRF1/ MEFs, showing that IRF1 is involved in MEK-mediated downregulation of IFN-inducible genes. Furthermore, IRF1 protein expression was lower in RasV12 cells compared with vector control NIH3T3 cells, but was restored to equivalent levels by inhibition of MEK. Similarly, the restoration of IRF1 expression by MEK inhibition was observed in human cancer cells. IRF1 re-expression in human cancer cells caused cells to become resistant to infection by the oncolytic vesicular stomatitis virus strain. Together, this work demonstrates that Ras/MEK activation in cancer cells downregulates transcription of IFN-inducible genes by targeting IRF1 expression, resulting in increased susceptibility to viral oncolysis.
Publication Title
Oncogenic Ras inhibits IRF1 to promote viral oncolysis.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 30 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Certain oncolytic viruses exploit activated Ras signalling in order to replicate in cancer cells. Constitutive activation of the Ras/MEK pathway is known to suppress the effectiveness of the interferon (IFN) antiviral response, which may contribute to Ras-dependent viral oncolysis. Here, we identified 10 human cancer cell lines (out of 16) with increased sensitivity to the anti-viral effects of IFN- after treatment with the MEK inhibitor U0126, suggesting that the Ras/MEK pathway underlies their reduced sensitivity to IFN. To determine how Ras/MEK suppresses the IFN response in these cells, we used DNA microarrays to compare IFN-induced transcription in IFN-sensitive SKOV3 cells, moderately resistant HT1080 cells, and HT1080 cells treated with U0126. We found that 267 genes were induced by IFN in SKOV3 cells, while only 98 genes were induced in HT1080 cells at the same time point. Furthermore, the expression of a distinct subset of IFN inducible genes, that included RIGI, GBP2, IFIT2, BTN3A3, MAP2, MMP7 and STAT2, was restored or increased in HT1080 cells when the cells were co-treated with U0126 and IFN. Bioinformatic analysis of the biological processes represented by these genes revealed increased representation of genes involved in the anti-viral response, regulation of apoptosis, cell differentiation and metabolism. Furthermore, introduction of constitutively active Ras into IFN sensitive SKOV3 cells reduced their IFN sensitivity and ability to activate IFN-induced transcription. This work demonstrates for the first time that activated Ras/MEK in human cancer cells induces downregulation of a specific subset of IFN-inducible genes.
Publication Title
Suppression of IFN-induced transcription underlies IFN defects generated by activated Ras/MEK in human cancer cells.
Sample Metadata Fields
Cell line, Treatment, Time
View Samples- Homo sapiens
- 27 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
With the goal of specifically dissecting the toxicogenomic signatures of the helper-dependent (HD) human (HAd5) and canine (CAV-2) adenovirus, the VSV-G-pseudotyped SIN HIV-1 (LV) and the Adenoviral-associated vector 2/9 for human neurons (AAV2/9), we transduced a bona fide human neuronal system with HD-HAd5, HD-CAV-2, LV and AAV2/9, we analysed the transcriptional response of more than 47,000 transcripts using gene chips.
Publication Title
Differentiated neuroprogenitor cells incubated with human or canine adenovirus, or lentiviral vectors have distinct transcriptome profiles.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 11 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Brain gene transfer using viral vectors will likely become a therapeutic option for several disorders. Helper-dependent (HD) canine adenovirus type 2 vectors (CAV-2) are well suited for this goal. Indeed, these vectors are poorly immunogenic, efficiently transduce neurons, are retrogradely transported to afferent structures in the brain, and lead to long-term transgene expression. CAV-2 vectors have been exploited to unravel behavior, cognition, neural networks, axonal transport and therapy for orphan diseases. Here we describe the HD-CAV-2 vector induced transcriptional response of human dopaminergic neurospheres derived from midbrain progenitors. In this 3D model system, brain cell functions and dynamics mimic several aspects the dynamic nature of human brain. With the goal of better understanding and characterizing HD CAV-2 for brain therapy, we analyzed the transcriptomic modulation induced by HD-CAV-2 in this brain model system.
Publication Title
Transcriptional Response of Human Neurospheres to Helper-Dependent CAV-2 Vectors Involves the Modulation of DNA Damage Response, Microtubule and Centromere Gene Groups.
Sample Metadata Fields
Specimen part, Time
View Samples- Homo sapiens
- 7 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
We have analyzed 2 normal B cells isolated from peripheral blood and 5 CLL specimens with affy 133A microarray for expression.
Publication Title
Aberrant splicing of the E-cadherin transcript is a novel mechanism of gene silencing in chronic lymphocytic leukemia cells.
Sample Metadata Fields
Specimen part, Disease, Disease stage
View Samples- Homo sapiens
- 12 Downloadable Samples
- Affymetrix Human Transcriptome Array 2.0 (hta20)
Description
Lung cancers are documented to have remarkable intratumoral genetic heterogeneity. However, little is known about the heterogeneity of biophysical properties, such as cell motility, and its relationship to early disease pathogenesis and micrometastatic dissemination. In this study, we identified and selected a subpopulation of highly migratory premalignant pulmonary epithelial cells that were observed to migrate through microscale constrictions at up to 100-fold the rate of unselected cells. This enhanced migratory capacity was found to be Rac1-dependent and heritable, as evidenced by maintenance of the phenotype through multiple cell divisions continuing more than 8-weeks post-selection. The morphology of this lung epithelial subpopulation was characterized by increased cell protrusion intensity. In a murine model of micrometastatic seeding and pulmonary colonization, the motility-selected premalignant cells exhibit both enhanced survival in short term assays and enhanced outgrowth of premalignant lesions in longer term assays, thus overcoming important aspects of metastatic inefficiency. Overall, our findings indicate that among premalignant pulmonary epithelial cells, subpopulations with heritable motility-related biophysical properties exist, and these may explain micrometastatic seeding occurring early in the pathogenesis of lung cancer. Understanding, targeting, and preventing these critical biophysical traits and their underlying molecular mechanisms may provide a new approach to prevent metastatic behavior.
Publication Title
Identification of a Human Airway Epithelial Cell Subpopulation with Altered Biophysical, Molecular, and Metastatic Properties.
Sample Metadata Fields
Age, Specimen part
View Samples- Mus musculus
- 6 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
PU.1 is a key transcription factor for macrophage differentiation. Novel PU.1 target genes were identified by mRNA profiling of PU.1-deficient progenitor cells (PUER) before and after PU.1 activation. We used two different types of Affymetrix DNA-microarrays (430 2.0 arrays and ST 1.0 exon arrays) to characterize the global PU.1-regulated transcriptional program underlying the early processes of macrophage differentiation.
Publication Title
Transcriptomic profiling identifies a PU.1 regulatory network in macrophages.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 32 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Mecp2 loss-of-function has been associated with altered gene expression in many tissues. We characterized gene expression changes within the hippocampi of 3 different Mecp2 loss-of-function mouse models.
Publication Title
An AT-hook domain in MeCP2 determines the clinical course of Rett syndrome and related disorders.
Sample Metadata Fields
Age, Specimen part
View Samples- Saccharomyces cerevisiae
- 18 Downloadable Samples
Illumina HiSeq 2000
Description
Classic ‘position effect’ experiments repositioned genes to the telomere to demonstrate that the epigenetic landscape can dramatically alter gene expression. Here we show that systematic gene knockout collections provide an exceptional resource for interrogating position effects, not only at the telomere but at every single genetic locus. Because deleted genes are replaced by the same reporter gene, interrogation of this reporter provides a sensitive probe into many different chromatin environments while controlling for genetic context. Using this approach we find that, whereas replacement of yeast genes with the kanMX marker does not perturb the chromatin landscape, differences due to gene position account for more than 35% of marker gene activity. We observe chromatin influences different from those reported previously, including an antagonistic interaction between histone H3 lysine 36 trimethylation (H3K36me3) and the Rap1 transcriptional activation site in kanMX that is mediated through a Set2-Rpd3-dependent pathway. This interaction explains why some yeast genes have been resistant to deletion and allows successful generation of these deletion strains using a modified transformation procedure. These findings demonstrate that chromatin regulation is not governed by a uniform ‘histone code’, but by specific interactions between chromatin and genetic factors. Overall design: Data included are RNA-Seq data for 4 heterzygous diploid yeast strains and diploid wild-type. Therea re three replicates for each heterzygous strain, and six replicates for wild-type.
Publication Title
Decoupling epigenetic and genetic effects through systematic analysis of gene position.
Sample Metadata Fields
Subject
View Samples- Homo sapiens
- 12 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Silver nanoparticles are used in consumer products like food contact materials, drinking water technologies and supplements, due to their antimicrobial properties. This leads to an oral uptake and exposure of intestinal cells. In contrast to other studies we found no apoptosis induction by surfactant coated silver nanoparticles in the intestinal cell model Caco-2 in a previous study, although the particles induced oxidative stress, morphological changes and cell death. Therefore, this study aimed to analyze the molecular mechanism of silver nanoparticles in Caco-2 cells. We used global gene expression profiling in differentiated Caco-2 cells, supported by verification of the microarray data by quantitative real time RT-PCR and microscopic analysis, impedance measurements and assays for apoptosis and oxidative stress. Our results revealed that the majority of surfactant coated silver nanoparticles are not taken up into differentiated Caco-2 cells. and probably affect the cells by outside-in signaling. They induce oxidative stress and have an influence on canonical pathways related to FAK, ILK, ERK, MAPK, integrins and adherence and tight junctions, thereby inducing transcription factors like AP1, NFB and NRF2, which mediate cellular reactions in response to oxidative stress and metal ions and induce changes in the cytoskeleton and cell-cell and cell-matrix contacts. The present data confirm the absence of apoptotic cell death. Non-apoptotic, necrotic cell death, especially in the intestine, can cause inflammation and influence the mucosal immune response.
Publication Title
Molecular mechanism of silver nanoparticles in human intestinal cells.
Sample Metadata Fields
Cell line
View Samples