Gene expression microarray profile for human embryonic kidney cells (HEK293T, CRL-11268) under untreated conditions.
The identification of protein kinase C iota as a regulator of the Mammalian heat shock response using functional genomic screens.
Specimen part, Cell line
View SamplesWe have determined the gene expression profile induced by 17 alpha-ethynyl estradiol (EE) in Ishikawa cells, a human uterine-derived estrogen-sensitive cell line, at various doses (1 pM, 100 pM, 10 nM, and 1 microM) and time points (8, 24, and 48 h). The transcript profiles were compared between treatment groups and controls (vehicle-treated) using high-density oligonucleotide arrays to determine the expression level of approximately 38,500 human genes. By trend analysis, we determined that the expression of 2560 genes was modified by exposure to EE in a dose- and time-dependent manner (p </= 0.0001). The annotation available for the genes affected indicates that EE exposure results in changes in multiple molecular pathways affecting various biological processes, particularly associated with development, morphogenesis, organogenesis, cell proliferation, cell organization, and biogenesis. All of these processes are also affected by estrogen exposure in the uterus of the rat. Comparison of the response to EE in both the rat uterus and the Ishikawa cells showed that 71 genes are regulated in a similar manner in vivo as well as in vitro. Further, some of the genes that show a robust response to estrogen exposure in Ishikawa cells are well known to be estrogen responsive, in various in vivo studies, such as PGR, MMP7, IGFBP3, IGFBP5, SOX4, MYC, EGR1, FOS, CKB, and CCND2, among others. These results indicate that transcript profiling can serve as a viable tool to select reliable in vitro systems to evaluate potential estrogenic activities of target chemicals and to identify genes that are relevant for the estrogen response.
The genomic response of a human uterine endometrial adenocarcinoma cell line to 17alpha-ethynyl estradiol.
No sample metadata fields
View SamplesGenomic, proteomic, and metabolomic technologies continue to receive increasing interest from environmental toxicologists. This interest is due to the great potential of these technologies to identify detailed modes of action and to provide assistance in the evaluation of a contaminant’s risk to aquatic organisms. Our experimental model is the zebrafish (Danio rerio) exposed to reference endocrine disrupting compounds in order to investigate compound-induced changes in gene transcript profiles. Adult, female zebrafish were exposed to 0, 15, 40, and 100 ng/L of 17 alpha-ethynylestradiol (EE2) and concentration and time-dependent changes in hepatic gene expression were examined using Affymetrix GeneChip® Zebrafish Genome Microarrays. At 24, 48, and 168 hours, fish were sacrificed and liver mRNA was extracted for gene expression analysis (24 and 168 hours only). In an effort to link gene expression changes to effects on higher levels of biological organization, body and ovary weights were measured and blood was collected for measurement of plasma steroid hormones (17 beta-estradiol (E2), testosterone (T)) and vitellogenin (VTG) using ELISA. EE2 exposure significantly affected GSI, E2, T, VTG and gene expression. We observed 1575 genes that were significantly affected (up- or down-regulated by at least 1.5-fold (p ? 0.001) in a concentration-dependent manner by EE2 exposure at either 24 or 168 hours. EE2 exposure altered transcription of genes involved in steroid hormone homeostasis, cholesterol homeostasis, retinoic acid metabolism, and cell growth and proliferation. Plasma VTG was significantly increased at 24, 48, and 168 hours (p<0.05) at 40 and 100 ng/L and at 15 ng/L at 168 hours. E2 and T were significantly reduced following EE2 exposure at 48 and 168 hours. GSI was decreased in a dose-dependent manner at 168 hours. In this study, we identified genes involved in a variety of biological functions that have the potential to be used as markers of exposure to estrogenic substances. Future work will evaluate the use of these genes in zebrafish exposed to weak estrogens to determine if these genes are indicative of exposure to estrogens with varying potencies.
Hepatic gene expression profiling using Genechips in zebrafish exposed to 17alpha-ethynylestradiol.
Sex, Specimen part, Compound, Time
View SamplesSox3 has been shown to be expressed within neural progenitors of the developing mouse central nervous system. However, identification of Sox3 targets within neural progenitors has remained elusive.
Dbx1 is a direct target of SOX3 in the spinal cord.
Specimen part, Cell line
View SamplesWe profile gene expression changes in two mutant strains lacking the D. melanogaster HP1 homolog HP1B at the third instar larval stage. Compared to the yw control strain, several hundred genes are deregulated, with metabolic genes being over-represented among the deregulated gene set. Overall design: Examination of gene expression in two genotypes
HP1B is a euchromatic Drosophila HP1 homolog with links to metabolism.
Specimen part, Cell line, Subject
View SamplesGene expression profiling is a promising diagnostic and prognostic tool. Expression profiles are snap-shots of mRNA levels at time of extraction and they have been shown to be affected by tissue handling during sample collection. The effect of cold (room temperature) ischemia in the time interval between surgical removal of the specimen and freezing has been described in a number of studies. However, not much is known about the effect of warm (body temperature) ischemia during surgery.
Differential effect of surgical manipulation on gene expression in normal breast tissue and breast tumor tissue.
Sex, Specimen part, Disease, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Profiling of the transcriptional response to all-trans retinoic acid in breast cancer cells reveals RARE-independent mechanisms of gene expression.
Cell line
View SamplesThe primary goal of toxicology and safety testing is to identify agents that have the potential to cause adverse effects in humans. Unfortunately, many of these tests have not changed significantly in the past 30 years and most are inefficient, costly, and rely heavily on the use of animals. The rodent cancer bioassay is one of these safety tests and was originally established as a screen to identify potential carcinogens that would be further analyzed in human epidemiological studies. Today, the rodent cancer bioassay has evolved into the primary means to determine the carcinogenic potential of a chemical and generate quantitative information on dose-response behavior in chemical risk assessments. Due to the resource-intensive nature of these studies, each bioassay costs $2 to $4 million and takes over three years to complete. Over the past 30 years, only 1,468 chemicals have been tested in a rodent cancer bioassay. By comparison, approximately 9,000 chemicals are used by industry in quantities greater than 10,000 lbs and nearly 90,000 chemicals have been inventoried by the U.S. Environmental Protection Agency as part of the Toxic Substances Control Act. Given the disparity between the number of chemicals tested in a rodent cancer bioassay and the number of chemicals used by industry, a more efficient and economical system of identifying chemical carcinogens needs to be developed.
Application of genomic biomarkers to predict increased lung tumor incidence in 2-year rodent cancer bioassays.
Sex, Age, Subject
View SamplesRetinoids, derivatives of vitamin A, are key physiological molecules with regulatory effects on cell differentiation, proliferation and apoptosis. As a result, they are of interest for cancer therapy. Specifically, models of breast cancer have varied responses to manipulations of the retinoid signaling cascade. This study characterizes the transcriptional response of MDA-MB-231 and MDA-MB-468 breast cancer cells to retinaldehyde dehydrogenase 1A3 (ALDH1A3) and to all-trans retinoic acid (atRA). We demonstrate limited overlap between ALDH1A3-induced gene expression and atRA-induced gene expression in both cell lines, suggesting that the function of ALDH1A3 in breast cancer progression extends beyond its role as a retinaldehyde dehydrogenase. Our data reveals divergent transcriptional responses to atRA, which are largely independent of genomic retinoic acid response elements (RAREs) and consistent with the opposing responses of MDA-MB-231 and MDA-MB-468 to in vivo atRA treatment. We identify transcription factors associated with each gene set. Manipulation of one of the transcription factors (i.e. interferon regulatory factor 1; IRF1) demonstrates that it is the level of atRA-inducible and epigenetically regulated transcription factors that determine expression of target genes (e.g. CTSS, cathepsin S). This study provides a paradigm for complex, combinatorial responses of breast cancer models to atRA treatment, and illustrates the need to characterize RARE-independent responses to atRA in a variety of models.
Profiling of the transcriptional response to all-trans retinoic acid in breast cancer cells reveals RARE-independent mechanisms of gene expression.
Cell line
View SamplesTo determine whether immortalized cells derived from the rat SCN (SCN 2.2) retain intrinsic rhythm-generating properties characteristic of the SCN, oscillatory properties of the SCN2.2 transcriptome were analyzed and compared to those found in the rat SCN in vivo using rat U34A Affymetrix GeneChips. SCN2.2 cells were expanded in 6-well plates. At 6-hour interval across 2 circadian cycles, cells from single 6-well plates were harvested and pooled for total RNA extraction.
Circadian profiling of the transcriptome in immortalized rat SCN cells.
No sample metadata fields
View Samples