The mTOR (mammalian Target of Rapamycin) pathway is constitutively activated in Diffuse Large B-Cell Lymphoma (DLBCL). mTOR inhibition has been shown to have clinical activity in patients with DLBCL, although overall response rates remain low. We therefore evaluated differences in the transcriptome between DLBCL cell lines with differential sensitivity to the mTOR inhibitor Rapamycin, to (A) identify gene-expression patterns(GEP) capable of identifying sensitivity to Rapamycin, (B) understand the underlying mechanisms of resistance to Rapamycin in DLBCL and (C) identify bioactive molecules likely to synergize with mTOR inhibitors. Using Affymetrix HuGene ST 1.0 microarrays, we were able to identify a gene expression signature capable of accurately predicting sensitivity and resistance to Rapamycin in DLBCL cell lines. Pathway analysis identified the serine/threonine kinase Akt as central to the differentially-expressed gene network. Connectivity mapping of our datasets identified compounds targeting the AKT pathway with a high likelihood of reversing the GEP associated with resistance to Rapamycin. Specifically, we evaluated the HIV protease inhibitor (PI) Nelfinavir, which is known to have anti-cancer and Akt-inhibitory properties, as well as the small molecule Akt inhibitor MK-2206, for their potential to synergize with to Rapamycin in DLBCL. Nelfinavir and MK-2206 caused profound inhibition of cell viability in combination with Rapamycin in DLBCL cell lines. Low nanomolar concentrations of Rapamycin inhibited phosphorylation of Akt and also downstream targets of activated mTOR when used in combination with these Akt inhibitors. These findings have the potential to significantly improve patient selection for mTOR inhibitor therapy, and to improve rates and depths of response. More broadly, they support the use of global RNA expression and connectivity mapping to improve patient selection and identify synergistic drug combinations for cancer therapy.
Akt inhibitors MK-2206 and nelfinavir overcome mTOR inhibitor resistance in diffuse large B-cell lymphoma.
Cell line
View SamplesGastrocnemius muscle biopsies were obtained from 15 health older adults without peripheral artery disease (PAD), 20 PAD patients with intermittent claudication, and 16 patients with critical limb ischemia undergoing limb amputation. Gene expression analysis was performed using RNA sequencing analysis. Overall design: Examination of gene expression differences across the clinical spectrum of PAD (healthy vs. claudicant vs. critical limb ischemia)
Extensive skeletal muscle cell mitochondriopathy distinguishes critical limb ischemia patients from claudicants.
Specimen part, Disease, Subject
View SamplesZFP57 is necessary for maintaining repressive epigenetic modifications at Imprinting control regions (ICRs). In mouse embryonic stem cells (ESCs), ZFP57 binds ICRs (ICRBS) and many other loci (non-ICRBS). To address the role of ZFP57 on all its target sites, we performed high-throughput and multi-locus analyses of inbred and hybrid mouse ESC lines carrying different gene knockouts. By using an allele-specific RNA-seq approach, we demonstrate that ZFP57 loss results in derepression of the imprinted allele of multiple genes in the imprinted clusters. We also find marked epigenetic differences between ICRBS and non-ICRBS suggesting that different cis-acting regulatory functions are repressed by ZFP57 at these two classes of target loci. Overall, these data demonstrate that ZFP57 is pivotal to maintain the allele-specific epigenetic modifications of ICRs that in turn are necessary for maintaining the imprinted expression over long distances. At non-ICRBS, ZFP57 inactivation results in acquisition of epigenetic features that are characteristic of poised enhancers, suggesting that another function of ZFP57 in early embryogenesis is to repress cis-acting regulatory elements whose activity is not yet required. Overall design: Examination of mRNA levels in Zfp57-/- mouse ESCs compared to the wild-type.
ZFP57 maintains the parent-of-origin-specific expression of the imprinted genes and differentially affects non-imprinted targets in mouse embryonic stem cells.
Specimen part, Cell line, Subject
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Cyclical expression of the Notch/Wnt regulator Nrarp requires modulation by Dll3 in somitogenesis.
Age, Specimen part
View SamplesRecent data from our group, demonstrate that infusion of myelin oligodendrocyte glycoprotein (MOG35-55) peptide, leads to induction of MOG35-55-specific Tregs and subsequent suppression of Experimental Autoimmune Encephalomyelitis (EAE), the mouse model of multiple sclerosis. Amelioration of EAE was accompanied by reduced MOG-specific Th1 and Th17 responses in the draining lymph nodes (dLNs). Phenotypic analysis of the dLNs of MOG-infused mice revealed a significant Treg-mediated reduction in the recruitment of 7AAD-CD3-CD19-CD11c+CD11bhighGr-1+ iDCs compared to non-infused control immunized mice. Focusing on the delineation of novel molecules/genes that are involved in the MOG-specific Treg-mediated suppression of autoimmune responses, we have isolated highly purified iDCs from MOG infused and non-infused control immunized mice.
De novo-induced self-antigen-specific Foxp3+ regulatory T cells impair the accumulation of inflammatory dendritic cells in draining lymph nodes.
Sex, Specimen part
View SamplesInhibition of FOXO1 activity in kidney microvascular endothelial cells improves angiogenesis Overall design: Kidney microvascular endothelial cells were serum starved and treated with DMSO control or FOXO1 inhibitor for one hour, then stimulated with VEGF for 30 minutes
Hyperactive FOXO1 results in lack of tip stalk identity and deficient microvascular regeneration during kidney injury.
Specimen part, Treatment, Subject, Time
View SamplesGold is widely considered to be a biologically inert element; however, it can elicit a profound biological response in plants. Plants can be exposed to significant levels of this precious metal in the environment from naturally occurring sources, as the result of mining activities or more recently resulting from the escalating use of nanoparticles in industry. In this microarray study we have investigated the gene expression response of Arabidopsis thaliana (Arabidopsis) to gold. Although the uptake of metal cations by plant transporters is well characterised, little is known about the uptake of gold, which exists in soil predominantly in a zero-valent state (Au0). We used this study to monitor the expression of candidate genes involved in metal uptake and transport. These show the down-regulation of a discreet number of genes known to be involved in the transport of copper, cadmium, nickel and iron.
Arabidopsis Glutathione Transferases U24 and U25 Exhibit a Range of Detoxification Activities with the Environmental Pollutant and Explosive, 2,4,6-Trinitrotoluene.
Specimen part, Treatment
View SamplesDifferential gene expression in preimplantation embryos has been documented, but few focused studies have been done to compare differential expression in human embryos after embryonic genome activation and specifically how they relate to blastocyst development. We hypothesized that blastocyst stage embryos would differentially express genes in pathways important in cell division, mobilization, and processes important in embryo implantation including endometrial apposition, adhesion, and invasion. We analyzed gene expression in 6 preimplantation human embryos.
Differentially expressed genes in preimplantation human embryos: potential candidate genes for blastocyst formation and implantation.
Specimen part
View SamplesNext to the two-component and quorum sensing systems, cell-surface signaling (CSS) has been recently identified as an important regulatory system in Pseudomonas aeruginosa. CSS senses signals from outside the cell and transmits them into the cytoplasm. It consists of a TonB-dependent outer membrane receptor, a cytoplasmic membrane-localized sigma factor regulator (or anti-sigma factor), and an extracytoplasmic function (ECF) sigma factor. Upon perception of the extracellular signal by the receptor the ECF sigma factor is activated and promotes the transcription of a specific set of gene(s). Although most P. aeruginosa ECF sigma factors are involved in the regulation of iron uptake, we have identified a novel ECF sigma factor (PA0675) involved in the regulation of virulence. By microarray analysis of cells overexpressing PA0675 from the pMUM3 plasmid we have identified the genes regulated by this sigma factor.
A Novel extracytoplasmic function (ECF) sigma factor regulates virulence in Pseudomonas aeruginosa.
No sample metadata fields
View SamplesAims/hypothesis: While lipid deposition in skeletal muscle is considered to be involved in obesity-associated insulin resistance, neutral intramyocellular lipid (IMCL) accumulation per se does not necessarily induce insulin resistance. We previously demonstrated that overexpression of the lipid droplet coat protein perilipin 2 augments intramyocellular lipid content while improving insulin sensitivity. Another member of the perilipin family, perilipin 5 (PLIN5), is predominantly expressed in oxidative tissues like skeletal muscle. Here we investigated the effects of PLIN5 overexpression in comparison with effects of PLIN2 on skeletal muscle lipid levels, gene expression profiles and insulin sensitivity. Methods: Gene electroporation was used to overexpress PLIN5 in tibialis anterior muscle of rats fed a high fat diet. Eight days after electroporation, insulin-mediated glucose uptake in skeletal muscle was measured by means of a hyperinsulinemic euglycemic clamp. Electron microscopy, fluorescence microscopy and lipid extractions were performed to investigate IMCL accumulation. Gene expression profiles were obtained using microarrays. Results: TAG storage and lipid droplet size increased upon PLIN5 overexpression. Despite the higher IMCL content, insulin sensitivity was not impaired and DAG and acylcarnitine levels were unaffected. In contrast to the effects of PLIN2 overexpression, microarray data analysis revealed a gene expression profile favoring FA oxidation and improved mitochondrial function. Conclusions/interpretation: Both PLIN2 and PLIN5 increase neutral IMCL content without impeding insulin-mediated glucose uptake. As opposed to the effects of PLIN2 overexpression, overexpression of PLIN5 in skeletal muscle promoted expression of a cluster of genes under control of PPAR and PGC1 involved in FA catabolism and mitochondrial oxidation.
Overexpression of PLIN5 in skeletal muscle promotes oxidative gene expression and intramyocellular lipid content without compromising insulin sensitivity.
Sex, Age, Specimen part, Treatment
View Samples