Filters
Technology
Platform
GSE55372
Saccharomyces cerevisiae
17 Downloadable Samples
Affymetrix Yeast Genome S98 Array (ygs98)
Description
Diurnal temperature cycling is an intrinsic characteristic of many exposed microbial ecosystems. However, its influence on yeast physiology and transcriptome has not been studied in detail. In this study, 24-h sinoidal temperature cycles, oscillating between 12 and 30C, were imposed on anaerobic, glucose-limited chemostat cultures of Saccharomyces cerevisiae. After three diurnal temperature cycles (DTC), concentrations of glucose, and extracellular metabolites, as well as CO2-production rates showed regular, reproducible circadian rhytms. DTC also led to waves of transcriptional activation and repression, which involved one sixth of the yeast genome. A substantial fraction of these DTC-responsive genes appeared to primarily respond to changes in glucose concentration. Elimination of known glucose-responsive genes revealed overrepresentation of previously identified temperature-responsive genes as well as genes involved in cell cycle and de novo purine biosynthesis. Analyses of budding index and flow cytomery demonstrated that DTC led to a partial synchronization of the cell cycle of the yeast populations in the chemostat cultures, which was lost upon release from DTC. Comparison of DTC results with data from steady-state cultures showed that DTC was sufficiently slow to allow S. cerevisiae chemostat cultures to almost completely acclimatize their transcriptome and physiology at the DTC temperature maximum, and to approach acclimation at the DTC temperature minimum.
Publication Title
Physiological and transcriptional responses of anaerobic chemostat cultures of Saccharomyces cerevisiae subjected to diurnal temperature cycles.
Sample Metadata Fields
No sample metadata fields
View Samples- Arabidopsis thaliana
- 6 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Systemic transcriptional responses in Arabidopsis thaliana distal leaves to wounding
Publication Title
The plant NADPH oxidase RBOHD mediates rapid systemic signaling in response to diverse stimuli.
Sample Metadata Fields
Age, Specimen part
View Samples- Homo sapiens
- 8 Downloadable Samples
- Affymetrix Human Genome U133A 2.0 Array (hgu133a2)
Description
The clinical efficacy of EGFR kinase inhibitors gefitinib and erlotinib is limited by the development of drug resistance. The most common mechanism of drug resistance is the secondary EGFR T790M mutation. Strategies to overcome EGFR T790M mediated drug resistance include the use of mutant selective EGFR inhibitors, including WZ4002, or by the use of high concentrations of irreversible quinazoline EGFR inhibitors such as PF299804. In the current study we develop drug resistant versions of the EGFR mutant PC9 cell line which reproducibly develops EGFR T790M as a mechanism of drug resistance to gefitinib. Neither PF299804 resistant (PFR) or WZ4002 resistant (WZR) clones of PC9 harbor EGFR T790M. Instead, they demonstrate activated IGF1R signaling as a result of loss of expression of IGFBP3 and the IGF1R inhibitor, BMS 536924, restores EGFR inhibitor sensitivity. Intriguingly, prolonged exposure to either PF299804 or WZ4002 results in the emergence of a more drug resistant subclone which contains ERK activation. A MEK inhibitor, CI-1040, partially restores sensitivity to EGFR/IGF1R inhibitor combination. Moreover, an IGF1R or MEK inhibitor used in combination with either PF299804 or WZ4002 completely prevents the emergence of drug resistant clones in this model system. Our studies suggest that more effective means of inhibiting EGFR T790M will prevent the emergence of this common drug resistance mechanism in EGFR mutant NSCLC. However, multiple drug resistance mechanisms can still emerge. Preventing the emergence of drug resistance, by targeting pathways activated in resistant cancers before they emerge, may be a more effective clinical strategy.
Publication Title
Resistance to irreversible EGF receptor tyrosine kinase inhibitors through a multistep mechanism involving the IGF1R pathway.
Sample Metadata Fields
Specimen part
View Samples- Danio rerio
- 6 Downloadable Samples
IlluminaHiSeq2500
Description
We report gene expression data for FACS sorted zebrafish mpeg1:mCherry + and mpx:EGFP + cells collected from whole embryos at 72 hours post fertilization (hpf). We also report gene expression data for the remaining, transgene negative, portion of these embryos. Overall design: ~1,000 mpeg1:mCherry+; mpx:EGFP+ transgenic embryos were homogenized, filtered, and sorted using FACS into PBS, collecting >50,000 cells for each of the three populations: mpeg1:mCherry+, mpx:EGFP+ and double negative (no double positive cells were collected as there was almost no overlap between mCherry and EGFP expression).
Publication Title
Distinct Roles for Matrix Metalloproteinases 2 and 9 in Embryonic Hematopoietic Stem Cell Emergence, Migration, and Niche Colonization.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 96 Downloadable Samples
- Illumina HumanHT-12 V4.0 expression beadchip
Description
High-throughput transcriptomic (HTTr) technologies are increasingly being used to screen environmental chemicals in vitro to identify molecular targets and provide mechanistic context for regulatory testing. The androgen receptor (AR, NR3C4) regulates male sexual development, is involved in the pathogenesis of a number of cancers, and is often the target of endocrine disruptors. Here, we describe the development and validation of a novel gene expression biomarker to identify AR-modulating chemicals using a pattern matching method. AR biomarker genes were identified by their consistent expression after exposure to 4 AR agonists and opposite expression after exposure to 4 AR antagonists. A genetic filter was used to include only those genes that were regulated by AR. Most of the resulting 51 biomarker genes were shown to be directly regulated by AR as determined by ChIP-Seq analysis of AR-DNA interactions. The biomarker was evaluated as a predictive tool using the fold-change rank-based Running Fisher algorithm which compares the expression of AR biomarker genes under various treatment conditions. Using 163 comparisons from cells treated with 98 chemicals, the biomarker gave balanced accuracies for prediction of AR activation or AR suppression of 97% or 98%, respectively. The biomarker was able to correctly classify 16 out of 17 AR reference antagonists including those that are weak and very weak. Predictions based on comparisons from AR-positive LAPC-4 cells treated with 28 chemicals in antagonist mode were compared to those from an AR pathway model based on 11 in vitro high-throughput screening assays that queried different steps in AR signaling. The balanced accuracy was 93% for suppression. Using our approach, we identified conditions in which AR was modulated in a large collection of microarray profiles from prostate cancer cell lines including 1) AR constitutively active mutants or knockdown of AR, 2) depletion of androgens by castration or removal from media, and 3) modulators that work through indirect mechanisms including suppression of AR expression. These results demonstrate that the AR gene expression biomarker could be a useful tool in HTTr to identify AR modulators in large collections of microarray data derived from AR-positive prostate cancer cell lines.
Publication Title
Identification of Androgen Receptor Modulators in a Prostate Cancer Cell Line Microarray Compendium.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 26 Downloadable Samples
- Illumina HiSeq 2500
Description
We studied alterations in gene expression profiles of the MCF7 human breast cancer cells caused by bisphenol A, bisphenol AF and glyphosate using Illumina RNA sequencing platform. Overall design: Examination of endocrine disrupting effects of xenobiotics using the MCF7 cell line
Publication Title
Editor's Highlight: Transcriptome Profiling Reveals Bisphenol A Alternatives Activate Estrogen Receptor Alpha in Human Breast Cancer Cells.
Sample Metadata Fields
Specimen part, Cell line, Subject
View Samples- Rattus norvegicus
- 34 Downloadable Samples
- Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
In order to gain insight into the effects of aging on susceptibility to environmental toxins, we characterized the expression of xenobiotic metabolizing enzymes (XMEs) from the livers of male Brown Norway and F344 rats across the adult lifespan. To examine metabolic processes across lifespan after challenge with a xenobiotic compound, Brown Norway rats were exposed to 1.0 g/kg body weight toluene by oral gavage in corn oil (4ml/kg body weight) or corn oil alone.
Publication Title
Coordinated changes in xenobiotic metabolizing enzyme gene expression in aging male rats.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 15 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Characterization of Peroxisome Proliferator-Activated Receptor alpha (PPAR(alpha)) - Independent Effects of PPAR(alpha) Activators in the Rodent Liver: Di-(2-ethylhexyl) phthalate Activates the Constitutive Activated Receptor
Publication Title
Characterization of peroxisome proliferator-activated receptor alpha--independent effects of PPARalpha activators in the rodent liver: di-(2-ethylhexyl) phthalate also activates the constitutive-activated receptor.
Sample Metadata Fields
Sex, Age, Treatment
View Samples- Mus musculus
- 3 Downloadable Samples
- Affymetrix Mouse Genome 430A 2.0 Array (mouse430a2)
Description
We analyzed the generation of mouse gliomas following the overexpression of PDGF-B in embryonic neural progenitors. Comparison of our microarray data, with published gene expression data sets for many different murine neural cell types, revealed a closest relationship between our tumor cells and oligodendrocyte progenitor cells, confirming definitively that PDGF-B-induced gliomas are pure oligodendrogliomas.
Publication Title
PDGF-B induces a homogeneous class of oligodendrogliomas from embryonic neural progenitors.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 21 Downloadable Samples
- Illumina HiSeq 2000
Description
Angioimmunoblastic T-cell lymphoma (AITL) is an aggressive lymphoid tumor derived from malignant transformation of T follicular helper (Tfh) cells. Genetically, AITL is characterized by loss of function mutations in the Ten-Eleven Translocation 2 (TET2) epigenetic tumor suppressor and a highly recurrent mutation (p.Gly17Val, G17V) in the RHOA small GTPase gene Moreover, RHOA G17V expression in Tet2 deficient hematopoietic progenitors resulted in the specific development of lymphoid tumors resembling human AITL. Notably, inhibition of ICOS signaling impaired the growth of RHOA G17V-induced mouse lymphomas in vivo, thus providing a potential new rational approach for the treatment of AITL. Overall design: We analyzed mRNA expression profiles of primary tumor cells expressing Rhoa G17V or Rhoa wild type.
Publication Title
RHOA G17V Induces T Follicular Helper Cell Specification and Promotes Lymphomagenesis.
Sample Metadata Fields
Specimen part, Subject
View Samples