Nonsense-mediated mRNA decay (NMD) is a molecular pathway of mRNA surveillance that ensures rapid degradation of mRNAs containing premature translation termination codons (PTCs) in eukaryotes. Originally, NMD was thought of as a quality control pathway that targets non-functional mRNAs arising from mutations and splicing errors. More recently, NMD has been shown to also regulate normal gene expression and NMD thus emerged as one of the key post-transcriptional mechanisms of gene regulation. We have now systematically analyzed the molecular mechanism of variable NMD efficiency and used different HeLa cell strains as a model system. The results of this analysis show that NMD efficiency can be remarkably variable and represents a stable characteristic of these strains. Low NMD efficiency is shown to be functionally related to the reduced abundance of the exon junction component RNPS1 in one of the HeLa strain analyzed. Furthermore, restoration of functional RNPS1 expression, but not of NMD-inactive mutant proteins, also restores efficient NMD in the RNPS1 deficient cell line. We conclude that cellular concentrations of RNPS1 modify NMD efficiency and propose that the cell type specific co-factor availability represents a novel principle that controls NMD.
The abundance of RNPS1, a protein component of the exon junction complex, can determine the variability in efficiency of the Nonsense Mediated Decay pathway.
Sex, Disease, Subject
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High expression of miR-125b-2 and SNORD116 noncoding RNA clusters characterize ERG-related B cell precursor acute lymphoblastic leukemia.
Specimen part, Disease, Disease stage
View SamplesERG-related B cell precursor acute lymphoblastic leukemia (BCP ALL) is a recently described childhood ALL subtype characterized by aberrant ERG protein expression and highly recurrent ERG intragenic deletions. Several studies reported a remarkably favourable outcome for ERG-related BCP-ALL despite a high incidence of apparently inauspicious IKZF1 aberrations. In this study we investigated by integrative genomic analysis the main features of the ERG-related group in a cohort of B-others BCP ALL patients enrolled in the AIEOP ALL 2000 therapeutic protocol. We report a specific microRNA and snoRNA signature that characterizes ERG-related patients with up-regulation of the miR-125b-2 cluster on chromosome 21 and several snoRNAs in the Prader-Willi locus at 15q11.2, including the orphan SNORD116 cluster. Given the current lack of parameters for a comprehensive classification we suggest toexploit the noncoding RNAs signature for differential diagnosis of ERG-related patients.
High expression of miR-125b-2 and SNORD116 noncoding RNA clusters characterize ERG-related B cell precursor acute lymphoblastic leukemia.
Specimen part, Disease, Disease stage
View SamplesTo explore the molecular basis for TSC22D4 function in hepatic lipid homeostasis in vivo TSC22D4 was knocked down in the mouse liver using adenovirus and performed genome wide expression analysis.
TSC22D4 is a molecular output of hepatic wasting metabolism.
Specimen part
View SamplesSeventeen T-ALL patients out of 120 (14.2%) presented CRLF2 expression 5 times higher than the median (CRLF2-high) with a significantly inferior 5-y EFS and an increased CIR compared to CRLF2-low patients.GEP of 15 T-ALL patients with (CRLF2-high) were compared to 15 CRLF2-low patients. GSEA identified cell cycle deregulating gene sets.
CRLF2 over-expression is a poor prognostic marker in children with high risk T-cell acute lymphoblastic leukemia.
Disease
View SamplesGene expression (mRNA) profiling of human ependymomas
Delineation of two clinically and molecularly distinct subgroups of posterior fossa ependymoma.
Sex, Age, Specimen part
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Analysis of microRNA transcriptome by deep sequencing of small RNA libraries of peripheral blood.
Specimen part, Cell line
View SamplesMicroRNAs are a class of small non-coding RNAs that regulate mRNA expression at the post-transcriptional level and thereby many fundamental biological processes. A number of methods, such as multiplex polymerase chain reaction, microarrays have been developed for profiling levels of known miRNAs. These methods lack ability to identify novel miRNAs and accurately determine expression at a range of concentration. Deep or massively parallel sequencing methods are providing suitable platforms for genome wide transcriptome analysis and have the ability to identify novel transcripts. The results of analysis of small RNA sequences obtained by Solexa technology of normal peripheral blood mononuclear cells, tumor cell lines K562 (chronic myelogenous leukemia) and HL60 (acute promyelogenous leukemia) are presented. Custom computation pipelines were used to generate expression profiles of known and for identification of novel miRNAs. Some of the highly expressed miRNAs in the leukocytes include several members of the let 7 family, mir-21, 103, 185, 191 and 320a. Comparison of the miRNA profiles of normal versus K562 cells or HL60 revealed a specific set of differentially expressed molecules. Correlation of the miRNA with that of mRNA expression profiles, obtained by microarray, revealed a set of target genes showing inverse correlation with miRNA levels. Our computational pipeline also predicted a number of novel miRNAs. Some of the predictions were validated by realtime RT-PCR and or RNAase protection assay. Overall design: The small RNA population from four samples - Two Normal Peripheral blood mononuclear cells (PBMC) samples, K562 cell line (This cell line is used as a model to study Chronic Myelogenous Leukemia), HL60 (This cell line is used to study acute promyelogenous leukemia) was sequenced using Solexa technology.
Analysis of microRNA transcriptome by deep sequencing of small RNA libraries of peripheral blood.
No sample metadata fields
View SamplesWe did microarray to compare the gene expression profile of peripheral blood mononuclear cells (PBMC from normal volunteer) and two leukemic cell lines that is K562 (Chronic myelogenous leukemia cell line), HL60 (Promyelocytic leukemia cell line) in order to find differentially expressed genes in these samples.
Analysis of microRNA transcriptome by deep sequencing of small RNA libraries of peripheral blood.
Specimen part, Cell line
View SamplesWe report RNA-Seq data of S.cerevisiae PPN1 knock-out yeast strain and PPN1 overproducing transformant yeast strain grown to logarithmic stage in control medium and in the medium containing 5mM manganese. Overall design: Yeast were grown to logarithmic growth stage in control YPD medium and in YPD medium with 5 mM MnSO4.
The Reduced Level of Inorganic Polyphosphate Mobilizes Antioxidant and Manganese-Resistance Systems in <i>Saccharomyces cerevisiae</i>.
Cell line, Subject
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