2,3,7,8-TCDD (TCDD) is a reproductive toxicant and endocrine disruptor in nearly all vertebrates, yet the mechanisms by which TCDD induces these reproductive alterations have not been fully characterized. Fish are among the most sensitive vertebrates to the toxic effects of TCDD, and even subtle physiologic changes induced by TCDD can impair reproduction. Previously, we have shown that chronic, sub-lethal exposure to TCDD decreased reproductive capacity, reduced serum estradiol and vitellogenin concentrations, and altered follicular development. Here we investigate the transcriptional changes in zebrafish ovary as they relate to observed attenuated estradiol concentrations and ovarian development. We used quantitative RT-PCR to assess TCDDs effects on the expression of several candidate genes important in the regulation of follicular development and steroidogenesis. Additionally, global changes in gene expression in the ovary caused by TCDD exposure were identified using Affymetrix Gene Chip Analysis. Our data suggest that TCDD may inhibit follicle maturation via attenuated gonadotropin responsiveness and/or depressed estradiol biosynthesis. Additionally, genes involved in glucose and lipid metabolism, regulation of transcription, and immune function were dysregulated by at least 2-fold suggesting that TCDD alters various integrated networks of signaling pathways. Approximately 89% of dysregulated transcripts contain putative AHR response elements (AHRE) within 5kb upstream of the predicted transcriptional start site suggesting ovarian toxicity is AHRE driven. Furthermore, approximately 49% of dysregulated transcripts contain putative estrogen response elements (ERE) suggesting that dysregulation of estrogen-responsive genes may also contribute to TCDD-induced attenuated follicular development. Patterns in gene expression were correlated with putative EREs and AHREs, and suggest that impacts on the regulation of transcription may play a large role in TCDDs ovarian toxicity. Taken together, these data illustrate the complexity of TCDDs ovarian toxicity.
Molecular targets of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) within the zebrafish ovary: insights into TCDD-induced endocrine disruption and reproductive toxicity.
Sex, Specimen part
View SamplesMIcrophthalmia-associated Transcription Factor (MITF) regulates melanocyte and melanoma physiology. ShRNA-mediated silencing of the NURF subunit BPTF revealed its essential role in several melanoma cell lines and in untransformed melanocytes in vitro. Comparative RNA-seq shows that MITF and BPTF co-regulate overlapping gene expression programs in cell lines in vitro. Somatic and specific inactivation of Bptf in developing murine melanoblasts in vivo shows that Bptf regulates their proliferation, migration and morphology. Once born, Bptf-mutant mice display premature greying where the second post-natal coat is white. This second coat is normally pigmented by differentiated melanocytes derived from the adult melanocyte stem cell (MSC) population that is stimulated to proliferate and differentiate at anagen. An MSC population is established and maintained throughout the life of the Bptf- mutant mice, but these MSCs are abnormal and at anagen, give rise to reduced numbers of transient amplifying cells (TACs) that do not express melanocyte markers and fail to differentiate into mature melanin producing melanocytes. MSCs display a transcriptionally repressed chromatin state and Bptf is essential for reactivation of the melanocyte gene expression program at anagen, the subsequent normal proliferation of TACs and their differentiation into mature melanocytes. Overall design: 5 samples corresponding to mRNA profiles of 501Mel and Hermes3A after BPTF shRNA-mediated knockdown were generated by deep sequencing in triplicate (Hermes 3A) or duplicate (501Mel), using HiSeq2500.
Chromatin-Remodelling Complex NURF Is Essential for Differentiation of Adult Melanocyte Stem Cells.
No sample metadata fields
View SamplesWe examined mRNA level changes in two mouse enteroids clones expressing different levels of PLAGL2 from a constitutive Piggybac transposon vector. Overall design: Expression analysis, PLAGL2 O/E vs. GFP O/E
The Zinc Finger Transcription Factor PLAGL2 Enhances Stem Cell Fate and Activates Expression of ASCL2 in Intestinal Epithelial Cells.
Specimen part, Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Histone Variant H2A.Z.2 Mediates Proliferation and Drug Sensitivity of Malignant Melanoma.
Cell line
View SamplesHere we report a novel role for H2A.Z.2 (H2AFV) as a mediator of cell proliferation and sensitivity to targeted therapies in malignant melanoma. While both H2A.Z.1 and H2A.Z.2 are highly expressed in metastatic melanoma and correlate with decreased patient survival, only H2A.Z.2 deficiency results in impaired cellular proliferation of melanoma cells, which occurs via a G1/S arrest. Integrated gene expression and ChIP-seq analyses revealed that H2A.Z.2 positively regulates E2F target genes, and that such genes acquire a distinct H2A.Z occupancy signature over the promoter and gene body in metastatic melanoma cells. We further identified the BET family member BRD2 as an H2A.Z-interacting protein in melanoma cells, and demonstrate that H2A.Z.2 silencing cooperates with BET inhibition to induce cell death.
Histone Variant H2A.Z.2 Mediates Proliferation and Drug Sensitivity of Malignant Melanoma.
Cell line
View SamplesHere we report a novel role for H2A.Z.2 (H2AFV) as a mediator of cell proliferation and sensitivity to targeted therapies in malignant melanoma. While both H2A.Z.1 and H2A.Z.2 are highly expressed in metastatic melanoma and correlate with decreased patient survival, only H2A.Z.2 deficiency results in impaired cellular proliferation of melanoma cells, which occurs via a G1/S arrest. Integrated gene expression and ChIP-seq analyses revealed that H2A.Z.2 positively regulates E2F target genes, and that such genes acquire a distinct H2A.Z occupancy signature over the promoter and gene body in metastatic melanoma cells. We further identified the BET family member BRD2 as an H2A.Z-interacting protein in melanoma cells, and demonstrate that H2A.Z.2 silencing cooperates with BET inhibition to induce cell death. Overall design: Expression levels for non tumorigenic (Melanocytes) and human melanoma cell line SKmel147, before and after JQ1 treatement
Histone Variant H2A.Z.2 Mediates Proliferation and Drug Sensitivity of Malignant Melanoma.
No sample metadata fields
View SamplesPurpose: The goal of the present study is to provide an independent assessment of the retinal transcriptome signatures of the C57BL/6J (B6) and DBA/2J (D2) mice and to enhance existing microarray datasets for accurately defining the allelic differences in the BXD recombinant inbred strains. Methods: Retinas from both B6 and D2 mice (3 of each) were used for the RNA-seq analysis. Transcriptome features were examined for both strains. Differentially expressed genes between the 2 strains were identified and bioinformatic analysis was performed to analyze the transcriptome differences between B6 and D2 strains, including Gene ontology (GO) analysis, Phenotype and Reactome enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. The RNA-seq data were then directly compared with one of the microarray datasets (DoD Retina Normal Affy MoGene 2.0 ST RMA Gene Level Microarray Database) hosted on GeneNetwork (www.genenetwork.org). Results: RNA-seq provided an in-depth analysis of the transcriptome of the B6 and D2 retina with a total of more than 30,000,000 reads per sample. Over 70% of the reads were uniquely mapped, resulting in a total of 18,100 gene counts for all 6 samples. 1,665 genes were differentially expressed, with 858 of these more highly expressed in B6 and 807 more highly expressed in D2. Several molecular pathways were differentially active between the two strains, including the retinoic acid metabolic process, endoplasmic reticulum lumen, extracellular matrix organization, and PI3K-Akt signaling pathway. The most enriched KEGG pathways were the pentose and glucuronate interconversions pathway, the cytochrome P450 pathway, protein digestion and absorption pathway and the ECM-receptor interaction pathway. Each of these pathways had a more than 4-fold enrichment. The DoD normal retina microarray database provided expression profiling for 26,191 annotated transcripts for B6 mouse, D2 mouse and 53 BXD strains. A total of 13,793 genes in this microarray dataset were comparable to the RNA-seq dataset. For both B6 and D2, the RNA-seq data and microarray data were highly correlated with each other (Pearson's r = 0.780 for B6 and 0.784 for D2). Our results suggest that the microarray dataset can reliably detect differentially expressed genes between the B6 and D2 retinas, with a positive predictive value of 45.6%, and a negative predictive value of 93.6%. Examples of true positive and false positive genes are provided. Conclusions: Retinal transcriptome features of B6 and D2 mouse strains provide a useful reference for a better understanding of the mouse retina. Generally, the microarray database presented on GeneNetwork shows good agreement with the RNA-seq data, while we note that any allelic difference between B6 and D2 should be verified with the latter. Overall design: Retinal mRNA profiles of 2 strains of mice, C57BL/6J and DBA/2J, were generated by deep sequencing, in triplicate, using Illumina TruSeq Stranded Total RNA kit.
RNA sequencing profiling of the retina in C57BL/6J and DBA/2J mice: Enhancing the retinal microarray data sets from GeneNetwork.
Specimen part, Cell line, Subject
View SamplesWe applied ribosome profiling and RNA sequencing to examine gene expression regulation during oncogenic cell transformation. One model involves normal mammary epithelial cells (MCF10A) containing ER-Src. Treatment of such cells with tamoxifen rapidly induces Src, thereby making it possible to kinetically follow the transition between normal and transformed cells. The other model consists of three isogenic cell lines derived from primary fibroblasts in a serial manner (Hahn et al., 1999). EH cell is immortalized by overexpression of telomerase (hTERT), and exhibits normal fibroblast morphology. EL cell expresses hTERT along with both large and small T antigens of Simian virus 40, and it displays an altered morphology but is not transformed. ELR cell expresses hTERT, T antigens, and an oncogenic derivative of Ras (H-RasV12). Overall design: Ribosome profiling and RNA sequencing in two cancer cell models
Many lncRNAs, 5'UTRs, and pseudogenes are translated and some are likely to express functional proteins.
No sample metadata fields
View SamplesMicrophthalmia-associated transcription factor (MITF) is the master regulator of the melanocyte lineage. By tandem affinity purification and mass spectrometry, we present a comprehensive characterisation of the MITF interactome comprising multiple novel cofactors involved in transcription, DNA replication and repair and chromatin organisation, including a BRG1 chromatin remodelling complex comprising CHD7. BRG1 is essential for melanoma cell proliferation in vitro and for normal melanocyte development in vivo. MITF and SOX10 actively recruit BRG1 to a set of MITF-associated regulatory elements (MAREs) at active enhancers. MITF, SOX10 and YY1 bind between two BRG1-occupied nucleosomes thus defining both a combinatorial signature of transcription factors essential for the melanocyte lineage and a specific chromatin organisation of MAREs. Nevertheless, BRG1 silencing enhances MITF occupancy at MAREs showing that BRG1 acts to promote dynamic MITF interactions with chromatin. Overall design: 19 samples corresponding to mRNA profiles of 501Mel and Hermes3A after MITF, BRG1 or control shRNA-mediated knockdown were generated by deep sequencing in triplicate (in duplicate for 501_shMITF and corresponding control 501_shSCR2), using HiSeq2500.
Transcription factor MITF and remodeller BRG1 define chromatin organisation at regulatory elements in melanoma cells.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
The nuclear bile acid receptor FXR is a PKA- and FOXA2-sensitive activator of fasting hepatic gluconeogenesis.
Sex, Specimen part, Treatment
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