Estimation of miRNAs
Ontology highlight
ABSTRACT:
ORGANISM(S): synthetic construct
SUBMITTER: Xiaoxiao Zhang
PROVIDER: E-GEOD-11176 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Our genome wide analyses of microRNA expression profiles involve the hybridization of fluorescently labeled RNA samples to custom made, DNA microarrays based on the GAPSII coated slides. We describe the differences in genome wide miRNA expressions between wild type 293 T mammalian cells and Ago2 transformed stable cell lines. Keywords: Expression Comparing one control and three Ago2-overexpressing stable cell lines (A, B, C). One replicate per array.
2010-05-19 | E-GEOD-11168 | biostudies-arrayexpress
Project description:Our genome wide analyses of microRNA expression profiles involve the hybridization of fluorescently labeled RNA samples to custom made, DNA microarrays based on the GAPSII coated slides. We describe a simple and effective method to regenerate such custom microarrays. Our protocol entails the use of a very low concentration of sodium hydroxide in a low salt buffer to strip RNA molecules from the arrays. The solution is also capable of removing DNA molecules hybridized to the slides, while preserving the slide coating and printed DNA probes. Slides can be stripped and reused at least twice without significantly sacrificing data quality. Keywords: expression study, new vs. stripped array comparison There are two stripping conditions in this study (1mM NaOH and 2mM NaOH in SSC buffer). For 1mM NaOH treatment, new, once-, twice-, and triple-stripped arrays are studies. For 2mM NaOH treatment, new and once-stripped arrays are measured.
2010-05-19 | E-GEOD-10305 | biostudies-arrayexpress
Project description:The high rates of mortality associated with epithelial ovarian cancer (EOC) are a direct consequence of its metastatic nature. Metastasis is dependent on many factors, among which activation of angiogenesis is most significant. Angiogenesis is, in turn, contingent upon the cellular response to hypoxia within the tumor microenvironment. Hypoxia-inducible factor 1 (HIF1) is a transcription factor composed of HIF1alpha and HIF1beta subunits and is the master regulator of the hypoxic response. It is therefore a critical mediator of tumor angiogenesis and metastasis. Regulation of HIF1 is primarily at the level of protein. In normoxia, the HIF1alpha subunit is hydroxylated via an oxygen- and iron-dependent mechanism and targeted for destruction. In hypoxia, low oxygen levels preclude hydroxylation and HIF1alpha is stabilized, allowing for its association with constitutively expressed HIF1beta to form bioactive HIF1. We have identified a novel mechanism of HIF1alpha regulation in EOC cells that involves microRNAs (miRs), ~22 nucleotide, non-coding RNA molecules that repress translation of target mRNAs by binding their 3’ untranslated regions (UTRs). Using microarray and qPCR analysis, we found that levels of miR-199a-1, a miR that is predicted in silico to target the HIF1alpha 3’ UTR, were reduced under hypoxia in EOC cells. We further demonstrated that miR-199a-1 directly targets the HIF1alpha 3’ UTR and overexpression of miR-199a-1 suppresses HIF1alpha protein levels and HIF1-driven gene expression. Moreover, cells stably overexpressing miR-199a-1 exhibit marked defects in migratory ability. These data were corroborated by our in vivo findings, which demonstrated that overexpression of miR-199a-1 causes significant reductions in tumor vessel density and tumor burden in nude mice. These findings provide insight into non-canonical, miR- and iron-based mechanisms of HIF1 regulation that may have important implications in the progression of EOC. miRNA expression analysis of A2780 epithelial ovarian cancer cells by microarrays
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Project description:Ago2 binds mature microRNAs (miRNAs) to regulate gene expression. A mutant Ago2 is constructed to render it unable to bind miRNAs and inhibit mRNA translation. Human 293T cells were transiently transfected with a plasmid that encoded a FLAG-tagged wildtype human Ago2 or mutant Ago2. FLAG IP was preformed, and assoicated RNA was isolated and subjected miRNA microarray analysis.
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Project description:Endotoxin/LPS tolerance is a tightly regulated phenomenon, which, during infection, prevents systemic hyper-inflammation. Here we report for the first time that morphine reversal of endotoxin tolerance resulting in persistent inflammation thus contributing to septicemia and septic shock. We further report that this regulation is mediated by LPS-induced down-regulation of microRNAs 146a and 155. However, only over-expression of miR-146a, but not miR-155 abrogates morphine mediated hyper-inflammation, while antagonizing miR-146a (but not miR-155) augments morphine mediated hyper-inflammation. Hence, miR-146a could be the potential therapeutic target for morphine-mediated abrogation of endotoxin tolerance. All treatments done in vivo. Morphine implanted subcuteniously, LPS administered as intraperitoneal injection.
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