Browse
Submit Data
Databases
API
Help

Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Revisiting Global Gene Expression Analysis (Microarray)

ABSTRACT: Gene expression analysis is a widely used and powerful method for investigating the transcriptional behavior of biological systems, for classifying cell states in disease and for many other purposes. Recent studies indicate that common assumptions currently embedded in experimental and analytical practices can lead to misinterpretation of global gene expression data. We discuss these assumptions and describe solutions that should minimize erroneous interpretation of gene expression data from multiple analysis platforms. RNA was extracted from cells expressing low or high levels of c-Myc. A panel of synthetic RNA's was added to these populations, based on cell number. Total RNA was then extracted and processed on Affymetrix microarrays in biological duplicate.

ORGANISM(S): Homo sapiens

SUBMITTER: Richard Young

PROVIDER: E-GEOD-40782 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Json Xml

Similar Datasets

Revisiting Global Gene Expression Analysis (RNA-Seq)

Project description:Gene expression analysis is a widely used and powerful method for investigating the transcriptional behavior of biological systems, for classifying cell states in disease and for many other purposes. Recent studies indicate that common assumptions currently embedded in experimental and analytical practices can lead to misinterpretation of global gene expression data. We discuss these assumptions and describe solutions that should minimize erroneous interpretation of gene expression data from multiple analysis platforms. Polyadenylated RNA depleted of ribosomal content was used for preparation of two independent sequencing libraries (low-Myc & high-Myc). A panel of synthetic RNA's was added to these populations, based on cell number.

2012-10-25 | E-GEOD-40783 | biostudies-arrayexpress

Chromatin occupancy of key transcriptional regulators in P493-6 cells with various levels of c-Myc expression

Project description:P493-6 cells are immortalized human peripheral B cells that carry a conditional, tetracycline-regulated myc gene. We present ChIP-seq analysis of key transcritional regulators in P493-6 cells expressing various levels of c-Myc: 0hr (low c-Myc levels), 1hr (intermediate c-Myc levels), 24hr (very high c-Myc levels) and No Tet (steady-state c-Myc levels). Brd4, c-Myc, Max, Med1, RNAPII, and the chromatin modification H3K27Ac were profiled in P493-6 cells

2012-11-14 | E-GEOD-42262 | biostudies-arrayexpress

Systematic Identification of Defined Conditions for Induction and Maintenance of Naive Human Pluripotency [expression]

Project description:Embryonic stem cells (ESCs) of mice and humans have distinct molecular and biological characteristics, raising the question whether an earlier ‘naive’ state of pluripotency may exist in humans. Here we took a systematic approach to identify small molecules that support autonomous self-renewal of naive human ESCs based on maintenance of endogenous OCT4 distal enhancer activity, a molecular signature of ground state pluripotency. Iterative chemical screening identified a combination of five kinase inhibitors that induces and maintains OCT4 distal enhancer activity when applied directly to conventional human ESCs. These inhibitors generate a homogeneous population of human pluripotent stem cells in which transcription factors associated with the ground state of pluripotency are highly upregulated. Comparison with previously reported naive human ESCs indicates that our kinase inhibitor cocktail captures a novel pluripotent state in humans that closely resembles mouse ESCs. Expression analysis was performed on two groups of human ESC samples: WIBR2 (P12 and P14), WIBR3 (P9) and WIN1 (P10) human ESCs derived in our optimized naive medium (5i/L/A or 6i/L/A, as indicated), and parental WIBR2 and WIBR3 human ESCs in primed human ESC medium.

2014-07-16 | E-GEOD-59430 | biostudies-arrayexpress

Systematic Identification of Defined Conditions for Induction and Maintenance of Naive Human Pluripotency

Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series

2014-07-16 | E-GEOD-59435 | biostudies-arrayexpress

Functional Retinal Pigment Epithelium-like Cells from Human Fibroblasts

Project description:The retinal pigment epithelium (RPE) provides vital support to photoreceptor cells and its dysfunction is associated with the onset and progression of age-related macular degeneration (AMD). Surgical provision of RPE cells may ameliorate AMD and thus it would be valuable to develop sources of patient-matched RPE cells for this application of regenerative medicine. We describe here the generation of functional RPE-like cells from fibroblasts that represent an important step toward that goal. We identified candidate master transcriptional regulators of RPEs using a novel computational method and then used these regulators to guide exploration of the transcriptional regulatory circuitry of RPE cells and to reprogram human fibroblasts into RPE-like cells. The RPE-like cells share key features with RPEs derived from healthy individuals, including morphology, gene expression and function, and thus represent a step toward the goal of generating patient-matched RPE cells for treatment of macular degeneration. Expression analysis was performed on induced retinal pigment epithelium-like cells.

2015-09-23 | E-GEOD-64264 | biostudies-arrayexpress

CDK7-dependent Transcriptional Addiction in Triple-Negative Breast Cancer (Microarray)

Project description:Triple-negative breast cancer (TNBC) is a highly aggressive form of breast cancer that exhibits extremely high levels of genetic complexity and yet a relatively uniform transcriptional program. We postulate that TNBC might be highly dependent on uninterrupted transcription of a key set of genes within this gene expression program and might therefore be exceptionally sensitive to inhibitors of transcription. Utilizing a novel kinase inhibitor and CRISPR/Cas9-mediated gene editing, we show here that triple-negative but not ER/PR+ breast cancer cells are exceptionally dependent on CDK7, a transcriptional cyclin-dependent kinase. TNBC cells are unique in their dependence on this transcriptional CDK and suffer apoptotic cell death upon CDK7 inhibition. An “Achilles cluster” of TNBC-specific genes are extremely sensitive to CDK7 inhibition and frequently associated with super-enhancers. We conclude that CDK7 mediates transcriptional addiction to a vital cluster of genes in TNBC and CDK7 inhibition may be useful therapy for this challenging cancer. Expression microarrays in H3K27ac in triple-negative breast cancer +/- treatment with covalent CDK7 inhibitor THZ1 treatment

2015-09-24 | E-GEOD-69106 | biostudies-arrayexpress

Selective transcriptional regulation by Myc in cellular growth control and lymphomagenesis [ChIP-Seq]

Project description:The c-myc proto-oncogene product, Myc, is a transcription factor that binds thousands of genomic loci. Recent work suggested that rather than up- and down-regulating selected groups of genes, Myc targets all active promoters and enhancers in the genome (a phenomenon termed "invasion") and acts as a general amplifier of transcription. However, the available data did not readily discriminate between direct and indirect effects of Myc on RNA biogenesis. We addressed this issue with genome-wide chromatin immunoprecipitation and RNA expression profiles during B-cell lymphomagenesis in mice, in cultured B-cells and fibroblasts. Consistent with long-standing observations, we detected general increases in total RNA or mRNA copies per cell (hereby termed "amplification") when comparing actively proliferating cells with control quiescent cells: this was true whether cells were stimulated by mitogens (requiring endogenous Myc for a proliferative response) or by deregulated, oncogenic Myc activity. RNA amplification and promoter/enhancer invasion by Myc were separable phenomena that could occur without one another. Moreover, whether or not associated with RNA amplification, Myc drove the differential expression of distinct subsets of target genes. Hence, while having the potential to interact with all active/poised regulatory elements in the genome, Myc does not directly act as a global transcriptional amplifier. Instead, our results imply that Myc activates and represses transcription of discrete gene sets, leading to changes in cellular state that can in turn feed back on global RNA production and turnover. Mapping c-Myc, RNAPII and H3K4me3, H3K4me1 and H3K27ac in four different models of Myc regulation Note: GEO Sample GSM894093 was used as input sample to generate processed data files P493.Myc.NoMyc.bed, P493.Myc.LowMyc.bed, P493.Myc.HighMyc.bed, P493.Myc.t1h.bed, P493.Myc.t24h.bed, P493.Pol2.NoMyc.bed, P493.Pol2.t24h.bed

2014-07-07 | E-GEOD-51004 | biostudies-arrayexpress

Enhancer Invasion and Transcriptional Amplification in Tumor Cells with Elevated c-Myc

Project description:Excessive expression of c-Myc occurs frequently in human cancers, where high levels are associated with tumor aggression and poor clinical outcome, but the effect of high levels of c-Myc on global gene regulation is poorly understood. We report here that in tumor cells expressing high levels of c-Myc, the transcription factor binds to E-box sequences in the core promoters of most actively transcribed genes and, unexpectedly, the enhancers of these active genes. The predominant effect of increasing c-Myc levels at both proximal and distal promoter elements is to produce higher levels of transcription at existing active genes by promoting RNA polymerase II elongation, as opposed to stimulating transcription of novel target genes. Our results argue that c-Myc overexpression drives increased transcription of growth-promoting genes, and does so by amplifying the levels of transcripts associated with the entire gene expression program of the cancer cell. Thus, excess c-Myc functions to elicit the transcriptional amplification of existing active genes through the invasion of enhancers across the cancer cell genome, thereby reducing the rate-limiting constraints required for continuous tumor growth and proliferation. ChIP-Seq of multiple factors and histone modifications in a variety of human tumor cell lines

2012-04-04 | E-GEOD-36354 | biostudies-arrayexpress

NF-kB coordinates rapid, BRD4-dependent remodeling of proinflammatory super-enhancers [Affymetrix]

Project description:Proinflammatory stimuli rapidly and globally remodel chromatin landscape, thereby enabling transcriptional responses. Yet, the mechanisms coupling chromatin regulators to the master regulatory inflammatory transcription factor NF-kB remain poorly understood. We report in human endothelial cells (ECs) that activated NF-kB binds to enhancers, provoking a rapid, global redistribution of BRD4 preferentially at super-enhancers, large enhancer domains highly bound by chromatin regulators. Newly established NF-kB super-enhancers drive nearby canonical inflammatory response genes. In both ECs and macrophages BET bromodomain inhibition prevents super-enhancer formation downstream of NF-kB activation, abrogating proinflammatory transcription. In TNFa-activated endothelium this culminates in functional suppression of leukocyte rolling, adhesion and transmigration. Sustained BET bromodomain inhibitor treatment of LDLr -/- animals suppresses atherogenesis, a disease process rooted in pathological vascular inflammation involving endothelium and macrophages. These data establish BET-bromodomains as key effectors of inflammatory response through their role in the dynamic, global reorganization of super-enhancers during NF-kB activation. Gene expression analysis of human endothelial cells in resting state, treatment with TNFalpha or TNFalpha with the BET bromodomain inhibitor JQ1

2014-09-29 | E-GEOD-53999 | biostudies-arrayexpress

Targeting of Super-Enhancer-Associated Oncogenic Transcription in MYCN-driven tumor cells by CDK7 inhibition [Gene Expression]

Project description:Global gene expression after CDK7 inhibition by THZ1 Global gene expression after genetic knockdown or overexpression of MYCN

2014-11-21 | E-GEOD-62724 | biostudies-arrayexpress