Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA177730 | ENA |
REPOSITORIES: ENA
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Project description:The cellular response to DNA damage is mediated through multiple pathways that regulate and coordinate DNA repair, cell cycle arrest and cell death. We show that the DNA damage response (DDR) induced by ionizing radiation (IR) is coordinated in breast cancer cells by selective mRNA translation mediated by high levels of translation initiation factor eIF4G1. Increased expression of eIF4G1, common in breast cancers, was found to selectively increase translation of mRNAs involved in cell survival and the DDR, preventing autophagy and apoptosis (Survivin, HIF1α, XIAP), promoting cell cycle arrest (GADD45a, p53, ATRIP, Chk1) and DNA repair (53BP1, BRCA1/2, PARP, Rfc2-5, ATM, MRE-11, others). Reduced expression of eIF4G1, but not its homolog eIF4G2, greatly sensitizes cells to DNA damage by IR, induces cell death by both apoptosis and autophagy, and significantly delays resolution of DNA damage foci with little reduction of overall protein synthesis. While some mRNAs selectively translated by higher levels of eIF4G1 were found to use internal ribosome entry site (IRES)-mediated alternate translation, most do not. The latter group shows significantly reduced dependence on eIF4E for translation, facilitated by an enhanced requirement for eIF4G1. Increased expression of eIF4G1 therefore promotes specialized translation of survival, growth arrest and DDR mRNAs that are important in cell survival and DNA repair following genotoxic DNA damage. The purpose of this study was to identify mRNAs that are selectively increased in translation by high levels of the initiation factor eIF4G1, which occurs in many advanced human cancers, in response to DNA damage caused by ionizing radiation,
2012-10-17 | GSE41627 | GEO
Project description:The cellular response to DNA damage is mediated through multiple pathways that regulate and coordinate DNA repair, cell cycle arrest and cell death. We show that the DNA damage response (DDR) induced by ionizing radiation (IR) is coordinated in breast cancer cells by selective mRNA translation mediated by high levels of translation initiation factor eIF4G1. Increased expression of eIF4G1, common in breast cancers, was found to selectively increase translation of mRNAs involved in cell survival and the DDR, preventing autophagy and apoptosis (Survivin, HIF1α, XIAP), promoting cell cycle arrest (GADD45a, p53, ATRIP, Chk1) and DNA repair (53BP1, BRCA1/2, PARP, Rfc2-5, ATM, MRE-11, others). Reduced expression of eIF4G1, but not its homolog eIF4G2, greatly sensitizes cells to DNA damage by IR, induces cell death by both apoptosis and autophagy, and significantly delays resolution of DNA damage foci with little reduction of overall protein synthesis. While some mRNAs selectively translated by higher levels of eIF4G1 were found to use internal ribosome entry site (IRES)-mediated alternate translation, most do not. The latter group shows significantly reduced dependence on eIF4E for translation, facilitated by an enhanced requirement for eIF4G1. Increased expression of eIF4G1 therefore promotes specialized translation of survival, growth arrest and DDR mRNAs that are important in cell survival and DNA repair following genotoxic DNA damage. The purpose of this study was to identify mRNAs that are selectively increased in translation by high levels of the initiation factor eIF4G1, which occurs in many advanced human cancers, in response to DNA damage caused by ionizing radiation, Polysome isolation was performed by separation of ribosome-bound mRNAs in sucrose gradients. Beckman Ultra-Clear centrifuge tubes were loaded with 5.5 ml of 50% sucrose in low salt buffer (LSB: 200 mM Tris pH7.4 in DEPC H2O, 100 mM NaCl, 30 mM MgCl2) with 1:1000 RNasin (Fermentas) and 100 μg/mL cycloheximide (CHX) in ethanol and incubated at 4°C horizontally overnight. Media was removed from cell cultures, replaced with media containing 100 μg/mL CHX, cells incubated at 37°C for 10 min to halt protein synthesis, and trypsinized in trypsin/EDTA containing 100 μg/mL CHX. Cells were washed twice in PBS containing CHX, RNasin and Roche complete EDTA-free protease inhibitor tablet, lysed in LSB with CHX and RNasin. Lysates were added to a Dounce homogenizer and incubated on ice for 3 min before addition of Triton detergent buffer (1.2% Triton N-100, 0.2M sucrose in LSB) and homogenization. Samples were transferred to cold sterile Eppendorf centrifuge tubes and centrifuged at 13,000 x RPM for 10 min at 4°C. Post-nuclear supernatants were transferred to centrifuge tubes containing 100 μL Heparin solution (10 mg/mL heparin, 1.5M NaCl in LSB) with RNasin and CHX, applied to a sucrose gradient. Gradients were centrifuged at 36K RPM at 4°C for 2 h, and supernatants recovered with an ISCO-UV fractionator. Samples were recovered into Eppendorf centrifuge tubes containing 40 μL RNase-free 0.5M EDTA and kept on ice. One volume acidic phenol-chloroform was added to each sample, which were then mixed and centrifuged at 10,000 x g for 15 min. The acidic phenol-chloroform extraction was repeated with the aqueous phase, which was then extracted twice via chloroform extraction. RNA was precipitated at -20°C overnight by addition of isopropanol with 0.1 vol NaOAc, pH5.2. The following day, RNA pellets were recovered by centrifugation, washed with 70% ethanol, air-dried and resuspended in sterile H2O. RNA from fractions was then pooled based on their relative rate of translation, with fractions containing 4 or more ribosomes considered heavily translated and used for gene chip analysis. The RNA quality was examined via the Agilent Technologies kit.
2012-10-17 | E-GEOD-41627 | biostudies-arrayexpress
Project description:We report the application of polysome profiling sequencing technology for high-throughput transcriptomics and translatomics in mammalian cells. We compare reduction of Dap5 to control in metastatic breast cancer cells in transcription and polysome enriched translation using RNA sequencing. Genome-wide transcriptomic and translatomic analyses indicate that DAP5 is required for translation of many transcription factor and receptor capped mRNAs and their mRNA targets involved in cell survival, motility, DNA repair and translation initiation, among other mRNAs.
2018-06-30 | GSE115142 | GEO
Project description:Identification of genes in DNA damage response and repair pathways differentially transcribed or translated under anoxia or hypoxia in GM05757 normal human fibroblast cells and DU145 human prostate cancer cells. Comparison of mRNA abundance and translation efficiency of genes in DNA damage response and repair pathways in selected anoxia/hypoxia-treated cells with those in normoxia-treated controls.
2015-07-01 | E-GEOD-52461 | biostudies-arrayexpress
Project description:Translation initiation factor 4G (eIF4G) is an integral component of the eIF4F complex which is key to translation initiation for most eukaryotic mRNAs. Many eIF4G isoforms have been described in diverse eukaryotic organisms but we currently have a poor understanding of their functional roles and whether they regulate translation in an mRNA specific manner. The yeast Saccharomyces cerevisiae expresses two eIF4G isoforms, eIF4G1 and eIF4G2, that have previously been considered as functionally redundant with any phenotypic differences arising due to alteration in eIF4G expression levels. Using homogenic strains that express eIF4G1 or eIF4G2 as the sole eIF4G isoforms at comparable expression levels to total eIF4G, we show that eIF4G1 is specifically required to mediate the translational response to oxidative stress. We use quantitative proteomics to show that eIF4G1 promotes oxidative stress-specific proteome changes.
2023-10-24 | PXD041682 | Pride
Project description:Cancer cells are known to reprogram their metabolism to adapt to adverse conditions dictated by tumor growth and microenvironment. A subtype of cancer cells with stem-like properties, known as cancer stem cells (CSC), is thought to be responsible for tumor recurrence. In this study, we demonstrated that CSC and chemoresistant cells derived from triple negative breast cancer cells display an enrichment of up- and downregulated proteins from metabolic pathways that suggests their dependence on mitochondria for survival. Here, we selected antibiotics, in particular - linezolid, inhibiting translation of mitoribosomes and inducing mitochondrial dysfunction. We provided the first in vivo evidence demonstrating that linezolid suppressed tumor growth rate, accompanied by increased autophagy. In addition, our results revealed that bactericidal antibiotics used in combination with autophagy blocker decrease tumor growth. This study puts mitochondria in a spotlight for cancer therapy and places antibiotics as effective agents for eliminating CSC and resistant cells.
2019-08-19 | MTBLS678 | MetaboLights
Project description:mTORC1/2 inhibition re-sensitizes platinum-resistant ovarian cancer by disrupting selective translation of DNA damage and survival mRNAs
| PRJNA478373 | ENA
Project description:The Ribo-seq and TI-seq analysis following i14G1s (eI1-eIF4G1 inhibitors) treatments uncover opposing roles of eIF1-eIF4G1 and eIF4E-eIF4G1 in scanning-dependent and independent translation. Furthermore, i14G1s inhibition of eIF4G1-eIF1 resulted in translation activation of ER/UPR stress-response genes via enhanced ribosome loading, elevated 5’UTR translation at near cognate AUGs, and unexpected concomitant upregulation of coding-region translation.
2022-07-07 | GSE166743 | GEO
Project description:The Ribo-seq and TI-seq analysis following i14G1s (eI1-eIF4G1 inhibitors) treatments uncover opposing roles of eIF1-eIF4G1 and eIF4E-eIF4G1 in scanning-dependent and independent translation. Furthermore, i14G1s inhibition of eIF4G1-eIF1 resulted in translation activation of ER/UPR stress-response genes via enhanced ribosome loading, elevated 5’UTR translation at near cognate AUGs, and unexpected concomitant upregulation of coding-region translation.
2022-07-07 | GSE166742 | GEO
Project description:We report the application of polysome profiling sequencing technology for high-throughput transcriptomics and translatomics in 4T1 cells. We compare reduction of Dap5 to control in a BALB/c mouse breast cancer cell line in transcription and polysome enriched translation using RNA sequencing. Genome-wide transcriptomic and translatomic analyses indicate that DAP5 is required for translation of many transcription factors and their mRNA targets involved in EMT, angiogenesis, DNA repair and translation initiation, among other mRNAs. Metastatic potential of cells is significanlty decreased upon Dap5 silencing as confirmed by different in vivo models.
2023-06-01 | GSE188733 | GEO