The cellular response to DNA damage is vital for maintaining genomic stability and preventing undue cell death or cancer formation. The DNA damage response (DDR), most robustly mobilized by double-strand breaks (DSBs), rapidly activates an extensive signaling network that affects numerous cellular systems, leading to cell survival or programmed cell death. A major component of the DDR is the widespread modulation of gene expression. We analyzed transcriptional responses to ionizing radiation (IR) in 5 human cell lines to elucidate the scope of this response and identify its gene targets. According to the mRNA expression profiles most of the responses were cell line-specific. Data analysis identified significant enrichment for p53 target genes and cell cycle-related pathways among groups of up-regulated and down-regulated genes, respectively.
Transcriptional modulation induced by ionizing radiation: p53 remains a central player.
Cell line, Time
View SamplesThe DNA damage response network modulates a wide array of signaling pathways, including DNA repair, cell cycle checkpoints, apoptotic pathways and numerous stress signals. The ATM protein kinase, functionally missing in patients with the human genetic disorder ataxia-telangiectasia (A-T), is a master regulator of this network when the inducing DNA lesions are double strand breaks. The ATM gene is also frequently mutated in sporadic cancers of lymphoid origin. Here, we applied a functional genomics approach that combines gene expression profiling and computational promoter analysis to obtain global dissection of the transcriptional response to ionizing radiation (IR) in murine lymphoid tissue. Cluster analysis revealed six major expression patterns in the data. Prominent among them was a gene cluster that contained dozens of genes whose response to irradiation was Atm-dependent. Computational analysis identified significant enrichment of the binding site signatures of the transcription factors NF-kB and p53 among promoters of these genes, pointing to the major role of these two transcription factors in mediating the Atm-dependent transcriptional response in the irradiated lymphoid tissue. Examination of the response showed that pro- and anti-apoptotic signals were simultaneously induced, with the pro-apoptotic pathway mediated by p53, and the pro-survival pathway by NF-kB. These findings further elucidate the molecular network induced by IR and have implications for cancer management as they suggest that a combined treatment that restores the p53-mediated apoptotic arm while blocking the NF-kB-mediated pro-survival arm could be most successful in increasing the radiosensitivity of lymphoid tumors.
Parallel induction of ATM-dependent pro- and antiapoptotic signals in response to ionizing radiation in murine lymphoid tissue.
No sample metadata fields
View SamplesWe intended to investigate effects of mmu-miR-15a-3p on gene expression in mice
Large-scale screening identifies a novel microRNA, miR-15a-3p, which induces apoptosis in human cancer cell lines.
Specimen part
View SamplesSurgical resection is the preferred treatment for Hepatocellular carcinoma; however, it induces tumor recurrence. Our objective was to understand the molecular mechanisms linking liver regeneration under chronic-inflammation to tumorigenesis. Mdr2-knockout mice, a model of inflammation-associated cancer, underwent partial-hepatectomy which led to enhanced hepatocarcinogenesis. Yet, liver regeneration in these mice was severely attenuated. We demonstrate the activation of the DNA damage response machinery and altered genomic instability during early liver inflammatory stages resulting in hepatocyte apoptosis and cell-cycle arrest, and suggest their involvement in tumor recurrence subsequent to partial hepatectomy. We propose that under the regenerative proliferative stress induced by liver resection, the genomic unstable hepatocytes generated during chronic-inflammation, escape apoptosis and reenter the cell-cycle, triggering the enhanced tumorigenesis
Accelerated carcinogenesis following liver regeneration is associated with chronic inflammation-induced double-strand DNA breaks.
No sample metadata fields
View SamplesMKR mice is a Type 2 Diabetic mice, which was created by expressing mutation in IGF1 receptor in the skeletal muscle, and is widely used in diabetes research. Gene expression differences between MKR mice and Healthy (Wild type) mice are poorly understood.
Multi-tissue computational modeling analyzes pathophysiology of type 2 diabetes in MKR mice.
Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Integrator regulates transcriptional initiation and pause release following activation.
Disease, Cell line, Treatment
View SamplesWe investigated the genomic occupancy of INTS11, in normal condition and after stimulation of EGF. Total RNAPII was profiled in the presence or absence of INTS11, along with the Super Elongation Complex proteins AFF4 and ELL2. Additionally, we extensively examined the transcriptional response to EGF, before and after depletion of INTS11, using RNA-seq on ribosome-depleted total RNA and Global Run-on sequencing (GRO-seq).
Integrator regulates transcriptional initiation and pause release following activation.
Cell line, Treatment
View SamplesConditioned media from a human embryonic germ cell-derived line called SDEC was found to be supportive of human embryonic stem cell growth in the absence of feeder layers on a simple type I collagen matrix. We performed gene expression studies comparing this line to non-supportive cell lines (WI-38 and Detroit 551) to try to identify gene targets responsible for this phenomenon.
Proliferation and pluripotency of human embryonic stem cells maintained on type I collagen.
Specimen part, Cell line
View SamplesElectrochemical gradients of monovalent cations across the plasma membrane (high intracellular potassium, [K+]i vs low intracellular sodium, [Na+]i) are created by the Na+,K+-pump and determine a large variety of physiologically important processes. We hypothesized that transcriptomics changes triggered by hypoxia are at least partially caused by Na+i/K+i-mediated excitation-transcription coupling .
Transcriptomic changes triggered by hypoxia: evidence for HIF-1α-independent, [Na+]i/[K+]i-mediated, excitation-transcription coupling.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Polycomb repressive complex 2-dependent and -independent functions of Jarid2 in transcriptional regulation in Drosophila.
Specimen part
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