Ovarian granulosa cells play a central role in steroidogenesis, which is critical for female reproduction. Follicle-stimulating hormone (FSH) promotes cAMPmediated signaling to regulate granulosa cell steroidogenesis. We have shown previously that 2, 2-bis-(p-hydroxyphenyl)-1, 1, 1-trichloroethane (HPTE) inhibits FSH- and dibutyryl cAMP-stimulated steroidogenesis, and affects the mRNA levels of steroidogenic pathway enzymes in rat granulosa cells. However, HPTE showed a differential effect in FSH- and cAMP-stimulated cells in that HPTE more completely blocked FSH- when compared to cAMP-driven steroidogenesis. The objective of this study was to analyze the effects of HPTE on global gene expression profiles in untreated granulosa cells and those challenged with FSH or cAMP. Granulosa cells from immature rats were cultured with 0, 1, 5, or 10 M HPTE in the presence and absence of either 3 ng FSH/ml or 1 mM cAMP for 48 h. Total RNA was isolated for microarray analysis using the GeneChip Rat Genome 230 2.0 and ArrayAssist Microarray Suite. An investigation of changes in gene expression across all HPTE treatments showed that HPTE altered more genes in FSH- (~670 genes) than in cAMP-stimulated cells (~366 genes). Analysis confirmed that HPTE more effectively inhibited FSH- than cAMP-induced steroid pathway gene expression and steroidogenesis. Furthermore, expression patterns of novel genes regulating signal transduction, transport, cell cycle, adhesion, differentiation, motility and growth, apoptosis, development, and metabolism were all altered by HPTE. This study further established that HPTE exerts differential effects within the granulosa cell steroidogenic pathway, and revealed that these effects include broader changes in gene expression.
Effect of the methoxychlor metabolite HPTE on the rat ovarian granulosa cell transcriptome in vitro.
No sample metadata fields
View SamplesTo analyze the role of DNA methylation during differentiation, we performed genome-wide expression analysis of undifferentiated wild type, dnmt1-/- and triple knock out (TKO; dnmt1-/-, dnmt3a-/-, dnmt3b-/-) ESCs as well as respective embryoid bodies (EBs) at two stages of differentiation
Global DNA hypomethylation prevents consolidation of differentiation programs and allows reversion to the embryonic stem cell state.
Specimen part
View SamplesTCP transcription factors from the CYC2-class are involved in the development of monosymmetric flowers in all core eudicot species analysed so far. In Antirrhinum majus, the CYC2/TCP transcription factor CYCLOIDEA (CYC) is the molecular key regulator driving the development of flower monosymmetry (Luo D, Carpenter R, Vincent C, Copsey L, Coen E: Origin of floral asymmetry in Antirrhinum. Nature 1996, 383:794-799). In the Brassicaceae Iberis amara, a stronger expression of the CYC2 gene IaTCP1 in the small adaxial petals likely leads to the reduced petal size in comparison to large abaxial petals, with hardly any IaTCP1 expression. This results in the formation of the monosymmetric Iberis flower (Busch A, Zachgo S: Control of corolla monosymmetry in the Brassicaceae Iberis amara. PNAS 2007, 104:16714-16719). In contrast, the orthologous TCP/CYC2 transcription factor TCP1 from Arabidopsis thaliana, which forms equally sized and shaped petal pairs, only shows an early and transient expression in the adaxial area of floral primordia. This implies that monosymmetry in the Brassicaceae evolved through a heterochronic expression shift of the TCP/CYC2 key regulator gene IaTCP1.
Differential transcriptome analysis reveals insight into monosymmetric corolla development of the crucifer Iberis amara.
Specimen part
View SamplesOver activation of the aryl hydrocarbon receptor (AhR) by TCDD results ampng other phenotypes in severe thymic atrophy accompanied by immunosuppression. The link between thymic atrophy, skewed thymocyte differntiation and immunosuppression is still not fully resolved. This study investigates the TCDD elicted exprssion changes in the ET, cortical thymus epithelial cell line.
Promoter analysis of TCDD-inducible genes in a thymic epithelial cell line indicates the potential for cell-specific transcription factor crosstalk in the AhR response.
Treatment, Time
View SamplesIncreased ploidy is common in tumors but treatments for tumors with excess chromosome sets are not available. Here, we characterize high-ploidy breast cancers and identify potential anticancer compounds selective for the high-ploidy state. Among 354 human breast cancers, 10% have mean chromosome copy number exceeding 3, and this is most common in triple negative and HER2-positive types. Women with high-ploidy breast cancers have higher risk of recurrence and death in two patient cohorts, demonstrating that it represents an important group for improved treatment. Because high-ploidy cancers are aneuploid, rather than triploid or tetraploid, we devised a two-step screen to identify selective compounds. The screen was designed to assure both external validity on diverse karyotypic backgrounds and specificity for high-ploidy cell types. This screen identified novel therapies specific to high-ploidy cells. First, we discovered 8-azaguanine, an antimetabolite that is activated by hypoxanthine phosphoribosyltransferase (HPRT), suggesting an elevated gene-dosage of HPRT in high-ploidy tumors can control sensitivity to this drug. Second, we discovered a novel compound, 2,3-Diphenylbenzo[g]quinoxaline-5,10-dione (DPBQ). DPBQ activates p53 and triggers apoptosis in a polyploid-specific manner, but does not inhibit topoisomerase or bind DNA. Mechanistic analysis demonstrates that DPBQ elicits a hypoxia gene signature and its effect is replicated, in part, by enhancing oxidative stress. Structure-function analysis defines the core benzo[g]quinoxaline-5,10 dione as being necessary for the polyploid-specific effects of DPBQ. We conclude that polyploid breast cancers represent a high-risk subgroup and that DPBQ provides a functional core to develop polyploid-selective therapy.
Identification of Selective Lead Compounds for Treatment of High-Ploidy Breast Cancer.
Cell line
View SamplesDose-dependent femoral gene expression was examined following repeated exposure (every 4 days for 28 days) to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). These data were used to examine the effect of repeated TCDD exposure on gene expression in the femur of C57BL/6 male mice. Overall design: Three biological replicates for each dose (0.01, 0.03, 0.1, 0.3, 1, 3, 10, 30) of TCDD and sesame oil vehicle
2,3,7,8-Tetrachlorodibenzo-p-dioxin dose-dependently increases bone mass and decreases marrow adiposity in juvenile mice.
Sex, Specimen part, Cell line, Treatment, Subject
View SamplesMicroarray data from G2-synchronized p53(+) and p53(-) fibroblasts before and after 3 h release from cell cycle blockade in the presence of 5 M sodium arsenite.
Exit from arsenite-induced mitotic arrest is p53 dependent.
No sample metadata fields
View SamplesDuring organogenesis of the intestine, reciprocal crosstalk between the endodermally-derived epithelium and the underlying mesenchyme is required for regional patterning and proper differentiation. Though both of these tissue layers participate in patterning, the mesenchyme is thought to play a prominant role in the determination of epithelial phenotype during development and in adult life. However, the molecular basis of this instructional dominance is unclear. In fact, surprisingly little is known about the cellular origins of many of the critical signaling molecules and the gene transcriptional events that they impact. Here, we profile genes that are expressed in separated mesenchymal and epithelial compartments of the perinatal mouse intestine. The data indicate that the vast majority of soluble modulators of signaling pathways such as Hedgehog, Bmp, Wnt, Fgf and Igf are expressed predominantly or exclusively by the mesenchyme, accounting for its ability to dominate instructional crosstalk. We also catalog the most highly enriched transcription factors in both compartments and find evidence for a major role for Hnf4alpha and Hnf4 gamma in the regulation of epithelial genes. Finally, we find that while epithelially enriched genes tend to be highly tissue-restricted in their expression, mesenchymally-enriched genes tend to be broadly expressed in multiple tissues. Thus, the unique tissue-specific signature that characterizes the intestinal epithelium is instructed and supported by a mesenchyme that itself expresses genes that are largely non-tissue specific.
Deconvoluting the intestine: molecular evidence for a major role of the mesenchyme in the modulation of signaling cross talk.
No sample metadata fields
View SamplesDose-dependent ileal gene expression was examined following repeated exposure (every 4 days for 28 days) to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). These data were used to examine the effect of repeated TCDD exposure on gene expression in the intestinal epithelium of C57BL/6 male mice. Overall design: Three biological replicates for each dose (0.01, 0.03, 0.1, 0.3, 1, 3, 10, 30) of TCDD and sesame oil vehicle
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)-elicited effects on bile acid homeostasis: Alterations in biosynthesis, enterohepatic circulation, and microbial metabolism.
Sex, Cell line, Treatment, Subject
View SamplesDose-dependent duodenal gene expression was examined following repeated exposure (every 4 days for 28 days) to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). These data were used to examine the effect of repeated TCDD exposure on gene expression in the intestinal epithelium of C57BL/6 male mice. Overall design: Three biological replicates for each dose (0.01, 0.03, 0.1, 0.3, 1, 3, 10, 30) of TCDD and sesame oil vehicle
Convergence of hepcidin deficiency, systemic iron overloading, heme accumulation, and REV-ERBα/β activation in aryl hydrocarbon receptor-elicited hepatotoxicity.
Sex, Specimen part, Cell line, Treatment, Subject
View Samples