Time-course and concentration-effect experiments with multiple time points and drug concentrations provide far more valuable information than experiments with just two design-points (treated vs. control), as commonly performed in most microarray studies. Analysis of the data from such complex experiments, however, remains a challenge. Here we present a semi-automated method for fitting time profiles and concentration-effect patterns, simultaneously, to gene expression data. The submodels for time-course included exponential increase and decrease models with parameters such as initial expression level, maximum effect, and rate-constant (or half-time). The submodel for concentration-effect was a 4-parameter Hill model.
Simultaneous modeling of concentration-effect and time-course patterns in gene expression data from microarrays.
No sample metadata fields
View SamplesThe HIF (hypoxia-inducible factor) transcription factor is the master regulator of the metazoan response to chronic hypoxia. In addition to promoting adaptations to low oxygen, HIF drives cytoprotective mechanisms in response to stresses and modulates neural circuit function. How most HIF targets act in the control of the diverse aspects of HIF-regulated biology remains unknown. We discovered that a HIF target, the C. elegans gene cyp-36A1, is required for numerous HIF-dependent processes, including modulation of gene expression, stress resistance, and behavior. cyp-36A1 encodes a cytochrome P450 enzyme that we show controls expression of more than a third of HIF-induced genes. CYP-36A1 acts cell non-autonomously by regulating the activity of the nuclear hormone receptor NHR-46, suggesting that CYP-36A1 functions as a biosynthetic enzyme for a hormone ligand of this receptor. We propose that regulation of HIF effectors through activation of cytochrome P450 enzyme/nuclear receptor signaling pathways could similarly occur in humans. Overall design: RNA-seq experiment characterizing C. elegans strains mutant for one or more member of the egl-9/hif-1/cyp-36A1 signaling pathway. Experiment was performed with two biological replicates per strain. N2 was used as the wild-type control.
Hypoxia-inducible factor cell non-autonomously regulates <i>C. elegans</i> stress responses and behavior via a nuclear receptor.
Specimen part, Subject
View SamplesHere we studied the effects of anticonvulsant drug exposure in a human embryonic stem cell (hESC) based neuro- developmental toxicity test (hESTn). During neural differentiation the cells were exposed, for either 1 or 7 days, to non-cytotoxic concentration ranges of valproic acid (VPA) or carbamazepine (CBZ), anti-epileptic drugs known to cause neurodevelopmental toxicity.
Gene Expression Regulation and Pathway Analysis After Valproic Acid and Carbamazepine Exposure in a Human Embryonic Stem Cell-Based Neurodevelopmental Toxicity Assay.
Time
View SamplesTo gain insight into the signaling pathway(s) required for ABL1/ABL2-dependent bone metastasis, we evaluated the consequences of single or double inactivation of ABL1 and ABL2 on the transcriptome of breast cancer cells. Double ABL1/ABL2 knockdown was required to decrease the levels of p-CrKL by more than 90%, indicative of inactivation of the endogenous ABL kinases. To examine the consequences of depleting the ABL kinases on the transcriptome of metastatic breast cancer cells we employed next generation sequencing (RNAseq) analysis. We found that 180 genes were significantly down-regulated and 40 genes were significantly up-regulated in ABL1/ABL2 knockdown cells. Overall design: Four samples were analyzed control, Abl single knockdown, Arg single knockdown, Abl/Arg double knockdown. Experiments were performed in triplicate.
ABL kinases promote breast cancer osteolytic metastasis by modulating tumor-bone interactions through TAZ and STAT5 signaling.
No sample metadata fields
View SamplesTo gain insight into the signaling pathway(s) required for ABL1/ABL2-dependent non-small cell carcinoma cells metastasis Overall design: Samples were analyzed by pair of either control versus ABL Kinase inhibitor GNF5, Or using scrambled shRNA versus ABL1/ABL2-specific shRNAs.
Inactivation of ABL kinases suppresses non-small cell lung cancer metastasis.
No sample metadata fields
View SamplesMYC is induced early in human adipose stem cells in response to a standard MDIR adipogenic cocktail. The objective of this experiment was to identify key gene networks impacted by MYC loss-of-function in a mixed donor pool of human derived adipose stem cells.
MYC is an early response regulator of human adipogenesis in adipose stem cells.
Sex, Race
View SamplesZebrafish embryos have been proposed as an attractive alternative model system for hepatotoxicity testing.
A transcriptomics-based hepatotoxicity comparison between the zebrafish embryo and established human and rodent in vitro and in vivo models using cyclosporine A, amiodarone and acetaminophen.
Compound
View SamplesAs part of a larger effort to provide proof-of-concept in vitro only risk assessments, we have developed a suite of high throughput assays for key readouts in the p53 DNA damage response toxicity pathway: DSB DNA damage (p-H2AX), permanent chromosomal damage (micronuclei; MN), p53 activation, p53 transcriptional activity, and cell fate (cell cycle arrest, apoptosis,MN). Dose-response studies were performed with these protein and cell fate assays, together with whole genome transcriptomics, for three prototype chemicals: etoposide (ETP), quercetin (QUE) and methyl methanesulfonate (MMS). Data were collected in a human cell line expressing wild-type p53 (HT1080) and results were confirmed in a second p53 competent cell line (HCT 116). At chemical concentrations causing similar increases in p53 protein expression, p53-mediated protein expression and cellular processes showed substantial chemical-specific differences. These chemical-specific differences in the p53 transcriptional response appear to be determined by augmentation of the p53 response by co-regulators. More importantly, dose-response data for each of the chemicals indicates that the p53 transcriptional response does not prevent MN induction at low concentrations. In fact, the no observed effect levels (NOELs) and benchmark doses (BMDs) for MN induction were less than or equal to those for p53-mediated gene transcription regardless of the test chemical, indicating that p53s post-translational responses may be more important than transcriptional activation in the response to low dose DNA damage. This effort demonstrates the process of defining key assays required for a pathway-based, in vitro-only risk assessment, using the p53-mediated DNA damage response pathway as a prototype.
Profiling dose-dependent activation of p53-mediated signaling pathways by chemicals with distinct mechanisms of DNA damage.
Specimen part, Cell line
View SamplesIn acute promyelocytic leukemia (APL), differentiation therapy with all-trans retinoic acid (ATRA)
Chemokine induction by all-trans retinoic acid and arsenic trioxide in acute promyelocytic leukemia: triggering the differentiation syndrome.
Specimen part
View SamplesWT J1 and 3B3L cells (in which Dnmt3B and Dnm3L are constitutively expressed from an exogenous construct) were cultured under both serum/LIF and 2i/LIF conditions. 3B3L cells do not show ground state-associated hypomethylation phenotype. This experiment sought to analyse the gene expression changes between the two conditions. Overall design: Three biological replicates per condition J1 serum, J1 2i, 3B3-3l serum, 3B3-3l 2i.
DNA Methylation Directs Polycomb-Dependent 3D Genome Re-organization in Naive Pluripotency.
Specimen part, Cell line, Subject
View Samples