Pluripotent-specific inhibitors (PluriSIns) make a powerful tool for studying the mechanisms that control the survival of human pluripotent stem cells (hPSCs). Here we characterize PluriSIn#2 as a novel selective indirect inhibitor of topoisomerase II alpha (TOP2A). We find that TOP2A is uniquely expressed in undifferentiated hPSCs, and that its inhibition results in their rapid cell death. These findings reveal a dependency of hPSCs on the activity of TOP2A, which can be harnessed for their selective elimination from culture.
Brief reports: Controlling the survival of human pluripotent stem cells by small molecule-based targeting of topoisomerase II alpha.
Specimen part, Cell line, Treatment
View SamplesBackground: The KRAS gene is mutated in about 40% of colorectal cancer (CRC) cases, which has been clinically validated as a predictive mutational marker of intrinsic resistatnce to anti-EGFR inhibitor (EGFRi) therapy. Since nearly 60% of patients with a wild type KRAS fail to respond to EGFRi treatment, there is a need to develop more reliable molecular signatures to better predict response. Here we address the challenge of adapting a gene expression signature predictive of RAS pathway activation, created using fresh frozen (FF) tissues, for use with more widely available formalin fixed paraffin-embedded (FFPE) tissues. Methods: In this study, we evaluated the translation of an 18-gene RAS pathway signature score from FF to FFPE in 54 CRC cases, using a head-to-head comparison of five technology platforms. FFPE-based technologies included the Affymetrix GeneChip (Affy), NanoString nCounter(NanoS), Illumina whole genome RNASeq (RNA-Acc), Illumina targeted RNASeq(t-RNA), and Illumina stranded Total RNA-rRNA-depletion (rRNA). Results: Using Affy_FF as the "gold" standard, initial analysis of the 18-gene RAS scores on all 54 samples shows varying pairwise Spearman correlations, with (1) Affy_FFPE(r=0.233, p=0.090); (2) NanoS_FFPE(r=0.608, p<0.0001); (3) RNA-Acc_FFPE(r=0.175, p=0.21); (4) t-RNA_FFPE (r=-0.237, p=0.085); and (5) t-RNA (r=-0.012, p=0.93). These results suggest that only NanoString has successful FF to FFPE translation. The subsequent removal of identified "problematic" samples (n=15) and gene (n=2) further improves the correlations of Affy_FF with three of the five technologies: Affy_FFPE (r=0.672, p<0.0001); NanoS_FFPE (r=0.738, p<0.0001); and RNA-Acc_FFPE (r=0.483, p=0.002). Conclusions: Of the five technology platforms tested, NanoString technology provides a more faithful translation of the RAS pathway gene expression signature from FF to FFPE than the Affymetrix GeneChip and multiple RNASeq technologies. Moreover, NanoString was the most forgiving technology in the analysis of samples with presumably poor RNA quality. Using this approach, the RAS signature score may now be reasonably applied to FFPE clinical samples. Overall design: Fifty-four (54) FFPE evaluable tumor specimens were selected from a larger multi-center cohort of 468 well-characterized colorectal adenocarcinoma patients whose tissues were obtained between October 2006 and September 2010 at the University of South Florida. The sample cohort was composed of tumor samples that were available as matched fresh-frozen (FF) and formalin-fixed paraffin-embedded (FFPE) pairs.
Adaptation of a RAS pathway activation signature from FF to FFPE tissues in colorectal cancer.
Specimen part, Subject
View SamplesThe goal of this study is to compare gene expression levels in the livers of larval Tg(fabp10:nls-mcherry) exposed to 1 mM inorganic arsenic from 4-120 hpf to the unexposed siblings. Samples were collected from Tg(fabp10:nls-mcherry) zebrafish larvae that were derived from incrossed parents of the same strain. The background of transgenic lines were typically from mixed outcrosses of the transgenics to AB, TAB5, and TAB14 strains when regenerating the lines as the working stocks aged. All samples were collected at approximately 120 hpf - natural spawning at 8:30-9:00AM EST on day zero, samples were collected at 8-10AM EST on day 5. Overall design: 10-20 livers from 5dpf embryos were pooled per sample of either control or 1 mM inorganic arsenic exposed Tg(fabp10:nls-mcherry) zebrafish larvae and RNA was extracted using the Zymo Quick-RNA Micro Kit with on-column DNase treatment. Libraries were prepared according to Illumina Truseq RNA sample prep kit, version 2, followed by Ribo-Zero Gold treatment.
Inorganic arsenic causes fatty liver and interacts with ethanol to cause alcoholic liver disease in zebrafish.
No sample metadata fields
View SamplesWe''ve recently shown that we can accelerate disease in a model of SLE (the NZB/W F1 model) using an anti-Ox40 mAb treatment regimen. The disease acceleration is rapid (within 2 weeks) but its unclear, mechanistically, how OX40 functions to promote disease. To that end we want to perform RNASeq on the sorted OX40-expressing CD4 T cells during treatment to understand how they function in response to OX40 signaling in vivo Overall design: RNASeq was performed on FACS sorted CD4 T cells from the spleen and kidney of NZB/W F1 lupus mice following anti-Ox40 agonist mAb treatment and disease acceleration
The Ox40/Ox40 Ligand Pathway Promotes Pathogenic Th Cell Responses, Plasmablast Accumulation, and Lupus Nephritis in NZB/W F1 Mice.
Cell line, Treatment, Subject
View SamplesWe''ve recently shown that we can accelerate disease in a model of SLE (the NZB/W F1 model) using an anti-Ox40 mAb treatment regimen. The disease acceleration is rapid (within 2 weeks) but its unclear, mechanistically, how Ox40 promotes disease. To that end we performed RNASeq on in vitro cultured CD4 T cells during Ox40 and TCR stimulation (in a reductionist setting) to understand how Ox40 signaling impacts cellular phenotype and function, including with and without TCR stimulation Overall design: RNASeq was performed on in vitro cultured CD4 T cells from the spleen of NZB/W F1 lupus prone mice, following anti-Ox40 mAb and anti-CD3/CD28 bead stimulation
The Ox40/Ox40 Ligand Pathway Promotes Pathogenic Th Cell Responses, Plasmablast Accumulation, and Lupus Nephritis in NZB/W F1 Mice.
Cell line, Subject
View SamplesWe hypothesized that patients with sarcoidosis have characteristic mRNA profiles. Microarray analysis of gene expression was done on peripheral blood. Comparing peripheral blood from patients with sarcoidosis to controls, 872 transcripts were upregulated and 1039 were downregulated at >1.5-fold change and a significant q value. Several transcripts associated with interferon and STAT1 were upregulated. Lung and lymph node analyses also showed dramatic increases in STAT1 and STAT1-regulated chemokines. Granulomas in lymph nodes of patients with sarcoidosis expressed abundant STAT1 and phosphorylated STAT1. STAT1 might play an important role in sarcoidosis. This novel hypothesis unites seemingly disparate observations with regard to sarcoidosis including implication of a casual role for interferons, a suspected infectious trigger, TH1 predominating lymphocytes in bronchoalveolar lavage, and the association with hypercalcemia.
Insights in to the pathogenesis of axial spondyloarthropathy based on gene expression profiles.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesThe response to the presence of the ncpBVDV-infected PI or TI fetus is expected to provide information on the impact of the PI fetus on the immune response of the dam
Persistent fetal infection with bovine viral diarrhea virus differentially affects maternal blood cell signal transduction pathways.
No sample metadata fields
View SamplesThe highly conserved Epidermal Growth Factor-receptor (Egfr) pathway is required in all animals for normal development and homeostasis; consequently, aberrant Egfr signaling is implicated in a number of diseases. Genetic analysis of Drosophila melanogaster Egfr has contributed significantly to understanding this conserved pathway and has led to the discovery of new components and targets. Here we used microarray analysis of Drosophila third instar wing discs, in which Egfr signaling was perturbed, to identify new Egfr-responsive genes. Upregulated transcripts included five known targets suggesting the approach was valid. We investigated the function of 29 previously uncharacterized genes, which had pronounced responses. The Egfr pathway is important for wing-vein patterning and using reverse genetic analysis we identified five genes that showed venation defects. Three of these genes are expressed in vein primordia and all showed transcriptional changes in response to altered Egfr activity consistent with being targets of the pathway. Genetic interactions with Egfr further linked two of the genes, Sulfated (Sulf1), an endosulfatase gene, and CG4096, an ADAMTS (A Disintegrin And Metalloproteinase with ThromboSpondin motifs) gene, to the pathway. Sulf1 showed a strong genetic interaction with the neuregulin-like ligand vein (vn) and may influence binding of Vn to heparan-sulfated proteoglycans (HSPGs). Genetic evidence also shows that CG4096 functions by modulating activity of the Egfr ligands. The substrate(s) and how ligand activity is affected are unknown, but interestingly vertebrate EGF ligands are regulated by a related ADAMTS protein. We conclude Sulf1 and CG4096 are negative feedback regulators of Egfr signaling that function in the extracellular space to influence ligand activity.
New negative feedback regulators of Egfr signaling in Drosophila.
Specimen part
View SamplesExamine global gene expression patterns in control and 35S:PAP1 Arabidopsis plants upon environmental perturbation (light and temperature) over the course of the experiments.
Environmental regulation of leaf colour in red 35S:PAP1 Arabidopsis thaliana.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
LEAFY target genes reveal floral regulatory logic, cis motifs, and a link to biotic stimulus response.
Specimen part
View Samples