Long-lasting activation of T cells requires up-regulation of many genes, for example of transcription factors, cytoskeletal proteins and cell surface proteins encluding ion channels. An increase of ion channel density at the cell surface reflects the needs to manage increased Ca2+ influx into the activated T cell. Using oligonucleotide-based arrays we have surveyed changes in ion channel mRNA expression that occur upon T cell activation. We used Affymetrix Analysis to confirmate our data achieved by self-designed glass array analysis.
A truncation variant of the cation channel P2RX5 is upregulated during T cell activation.
No sample metadata fields
View SamplesAmyotrophic lateral sclerosis and primary lateral sclerosis are two syndromic variants within the motor neurone disease spectrum. Whilst primary lateral sclerosis is associated with loss of upper motor neurons and a more benign disease course up to 17yrs, amyotrophic lateral sclerosis is caused by loss of both upper and lower motor neurons and has an average disease course of 2-3 years. The majority of cases are sporadic, thereby limiting the availability of cellular models for investigating pathogenic disease mechanisms.
Gene expression signatures in motor neurone disease fibroblasts reveal dysregulation of metabolism, hypoxia-response and RNA processing functions.
Specimen part, Disease
View SamplesOncolytic 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.
Oncogenic Ras inhibits IRF1 to promote viral oncolysis.
No sample metadata fields
View SamplesCertain 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.
Suppression of IFN-induced transcription underlies IFN defects generated by activated Ras/MEK in human cancer cells.
Cell line, Treatment, Time
View SamplesMononucleotide A and T repeats are abundant in human genome. Many of A repeats are bound by Argonaute proteins (AGOs). To evaluate the role of AGOs and A repeats in gene regulation, HEK293 cells were treated with 8-amino-3,6-dioxaoctanoic acid added peptide nucleic acid (PNA) AAAAAAAAAAAAAAA oligo (OO-A(15)).
Upstream mononucleotide A-repeats play a cis-regulatory role in mammals through the DICER1 and Ago proteins.
Cell line, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Developmentally regulated higher-order chromatin interactions orchestrate B cell fate commitment.
Specimen part
View SamplesProductive rearrangement of the immunoglobulin heavy chain locus triggers a major developmental checkpoint that promotes limited clonal expansion of pre-B cells, culminating in cell cycle arrest and rearrangement of the kappa () or lambda () light-chain loci. B lineage cells lacking the related transcription factors IRF-4 and IRF-8 undergo a developmental arrest at the cycling pre-B cell stage and are blocked for light-chain recombination. Using Irf-4,8-/- pre-B cells we demonstrate that two pathways converge to synergistically drive light-chain rearrangement, a process that is not simply activated by cell cycle exit. One pathway is directly dependent on IRF-4, whose expression is elevated by pre-BCR signaling. IRF-4 targets the 3 and enhancers to increase locus accessibility and positions a kappa allele away from pericentromeric heterochromatin. The other pathway is triggered by attenuation of IL-7 signaling and results in activation of the intronic enhancer via binding of the transcription factor, E2A. Intriguingly, IRF-4 regulates the expression of CXCR4 and promotes the migration of pre-B cells in response to the chemokine CXCL12. We propose that IRF-4 coordinates the two pathways regulating light-chain recombination by positioning pre-B cells away from IL-7 expressing stromal cells.
Regulation of immunoglobulin light-chain recombination by the transcription factor IRF-4 and the attenuation of interleukin-7 signaling.
No sample metadata fields
View SamplesOrganization of the genome in 3D nuclear-space is known to play a crucial role in regulation of gene expression. However, the chromatin architecture that impinges on the B cell-fate choice of multi-potent progenitors remains unclear. By employing in situ Hi-C, we have identified distinct sets of genomic loci that undergo a developmental switch between permissive and repressive compartments during B-cell fate commitment. Intriguingly, we show that topologically associating domains (TADs) represent co-regulated subunits of chromatin and display considerable structural alterations as a result of changes in the cis-regulatory interaction landscape. The extensive rewiring of cis-regulatory interactions is closely associated with differential gene expression programs. Further, we demonstrate the regulatory role of Ebf1 and its downstream factor, Pax5, in chromatin reorganization and transcription regulation. Together, our studies reveal that alterations in promoter and cis-regulatory interactions underlie changes in higher-order chromatin architecture, which in turn determines cell-identity and cell-type specific gene expression patterns.
Developmentally regulated higher-order chromatin interactions orchestrate B cell fate commitment.
Specimen part
View SamplesWe have determined that sustained expression of EBF suppresses alternate lineage genes independently of Pax5.
Transcription factor EBF restricts alternative lineage options and promotes B cell fate commitment independently of Pax5.
No sample metadata fields
View SamplesSolid cancers develop within a supportive microenvironment that promotes tumor formation and continued growth through the elaboration of mitogens and chemokines. Within these tumors, monocytes (macrophages and microglia) represent rich sources of these stromal factors. Leveraging a genetically-engineered mouse model of neurofibromatosis type 1 (NF1) low-grade brain tumor (optic glioma), previous studies have demonstrated that microglia are important for glioma formation and maintenance. To identify the tumor-associated microglial factors that support glioma growth (gliomagens), we employed a comprehensive large scale discovery effort using optimized advanced RNA-sequencing methods. Candidate gliomagens were prioritized to identify potential secreted or membrane-bound proteins, which were next validated by quantitative RT-PCR and RNA FISH following minocycline-mediated microglial inactivation in vivo. Using these selection criteria, Ccl5 was identified as a highly expressed chemokine in both genetically engineered Nf1 mouse and human optic gliomas. As a candidate gliomagen, recombinant Ccl5 increased Nf1-deficient optic nerve astrocyte growth in vitro. Importantly, consistent with its critical role in maintaining tumor growth, Ccl5 inhibition with neutralizing antibodies reduced Nf1 mouse optic glioma growth in vivo. Collectively, these findings establish Ccl5 as critical stromal growth factor in low-grade glioma maintenance relevant to future microglia-targeted therapies for brain tumors. Overall design: Nf1 optic glioma associated microglia from mice were flow sorted. Upregulated genes of glioma associated microglia were verified and further examined.
RNA Sequencing of Tumor-Associated Microglia Reveals Ccl5 as a Stromal Chemokine Critical for Neurofibromatosis-1 Glioma Growth.
No sample metadata fields
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