Deficiencies in the ATM gene are the underlying cause for ataxia telangiectasia, a congenital syndrome characterized by neurological, motor and immunological defects, as well as a predisposition to cancer risks. MicroRNAs (miRNAs) are small regulators of post-transcriptional gene expression and a useful tool for cancer diagnosis, staging, and prediction of therapeutic responses to clinical regimens. In particular, miRNAs have been used to develop signatures for breast cancer profiling. We are interested in the consequences of ATM deficiency on miRNA expression in breast epithelial cells and the potential contribution to cancer predisposition. In this study we investigate the effects of ATM loss on the miRNA expression and related gene expression changes in normal human mammary epithelial cells (HME-CC). We have identified 81 significantly differently expressed miRNAs in the ATM-deficient HME-CCs using small RNA sequencing. Many of these differentially expressed miRNAs have been described and implicated in tumorigenesis and proliferation. These changes include down-regulation of tumor suppressor miRNAs, such as hsa-miR-29c and hsa-miR-16, as well as the over-expression of pro-oncogenic miRNAs hsa-miR-93 and hsa-mir-221. All 81 miRNAs were combined with genome wide gene expression profiles to investigate possible targets of miRNA regulation. We identified messenger RNA (mRNA) targets of these miRNAs that were also significantly regulated after the depletion of ATM. Predicted targets included many genes implicated in cancer formation and progression, including SOCS1 and the proto-oncogene MAF. Integrated analysis of miRNA and mRNA expression allows us to build a more complete understanding of the pathways and networks involved in the breast cancer predisposition observed in individuals deficient in ATM. This study highlights miRNA and predicted mRNA target expression changes in ATM-deficient HME-CCs and suggests a mechanism for the breast cancer-prone phenotype seen in ATM deficient cells and patients. Additionally, this study provides preliminary data for defining miRNA profiles that may be used prognostic biomarkers for breast cancer predisposition. Overall design: Examination of small RNA population in human mammary epithelial cell lines. Each condition was preformed in triplicate.
Genome-wide small RNA sequencing and gene expression analysis reveals a microRNA profile of cancer susceptibility in ATM-deficient human mammary epithelial cells.
Specimen part, Cell line, Subject
View SamplesThe objective of this set of samples is to identify genes that are differentially expressed following the introduction of DNA double strand breaks (DSBs) by ionizing radiation in wild-type murine pre-B cells. The data generated in this project will be compared to the data generated in GSE9024, in which genes that are differentially expressed following the introduction of DNA double strand breaks (DSBs) by the Rag proteins in murine pre-B cells were examined. In order to understand the differences between the physiologic and genotoxic responses to DSB DNA damage, we need to compare cells that are all in the same compartment of the cell cycle. We are therefore examining the response to IR-induced damage in cells that are arrested in G1, which would correspond to our previous study of G1 arrested cells with Rag-induced breaks. This will illuminate the difference directly, allowing us to better understand the signaling responses to the different types of DNA damage.
DNA damage activates a complex transcriptional response in murine lymphocytes that includes both physiological and cancer-predisposition programs.
Specimen part
View SamplesThe objective is to identify genes that are differentially expressed following the introduction of DNA double-strand breaks (DSBs) by the Rag proteins in murine pre-B cells. Cells lacking Artemis are used since the Rag-induced DSBs will not be repaired, and thus, will provide a continuous stimulus to the cell.
DNA damage activates a complex transcriptional response in murine lymphocytes that includes both physiological and cancer-predisposition programs.
Specimen part, Disease, Treatment
View SamplesEffects of SOCS3 on the transcriptional response of bone marrow-derived macrophages to IL-6.
SOCS3 regulates the plasticity of gp130 signaling.
No sample metadata fields
View SamplesThe use of calcineurin inhibitor (CI) immunosuppressants has significantly improved the early allograft survival rate in organ transplantation. However, CI therapy has been associated with chronic nephrotoxicity, which limits their long-term utility. In order to understand the mechanisms of the toxicity, we analyzed the gene expression changes that underlie the development of CI immunosuppressant-mediated nephrotoxicity, in male Sprague-Dawley (SD) rats dosed daily with cyclosporine (CsA), FK506 or rapamycin (Rapa) for 1 to 28 days. We identified a group of genes, whose expression in rat kidney is quantitatively correlated with CI-induced kidney injury as observed in changes in blood urea nitrogen (BUN) levels and kidney histopathology. These genes include both up-regulated genes, such as Ren1 and Klks3, and down-regulated genes, such as Calb1, Egf, NCC, and kidney specific Wnk1 (KS-Wnk1). Using the down-regulated genes alone we successfully predicted CI immunosuppressant-mediated kidney injury in rats following 7 days of treatment. Among these genes are two mechanism-related genes, NCC and KS-Wnk1, both of which are involved in the sodium transport in the distal nephrons. The down-regulation of both genes at the mRNA and protein level in rat kidney following CI treatment was confirmed by quantitative RT-PCR and immunohistochemical staining, respectively. We hypothesize that decreased expression of NCC may cause reduced sodium chloride reabsorption in the distal tubules, and contribute to the prolonged activation of the Renin-Angiotensin-System (RAS), a demonstrated contributor to the development of CI-induced nephrotoxicity in both animal models and clinical settings. Therefore, NCC and KS-Wnk1 could potentially be used as biomarkers for early detection and prevention of CI-related nephrotoxicity in clinical practice.
Genomic-derived markers for early detection of calcineurin inhibitor immunosuppressant-mediated nephrotoxicity.
Sex, Specimen part
View SamplesThe primary goal of this study was to compare the performances of Rhesus Macaque Genome Array and Human Genome U133 Plus 2.0 Array with respect to the detection of differential expressions when rhesus macaque RNA extracts were labeled and hybridized.
Large scale analysis of positional effects of single-base mismatches on microarray gene expression data.
Specimen part, Cell line
View SamplesMany thousand long non-coding (lnc) RNAs are mapped in the human genome. Time consuming studies using reverse genetic approaches by post-transcriptional knock-down or genetic modification of the locus demonstrated diverse biological functions for a few of these transcripts. The Human Gene Trap Mutant Collection in haploid KBM7 cells is a ready-to-use tool for studying protein-coding gene function. As lncRNAs show remarkable differences in RNA biology compared to protein-coding genes, it is unclear if this gene trap collection is useful for functional analysis of lncRNAs. Here we use the uncharacterized LOC100288798 lncRNA as a model to answer this question. Using public RNA-seq data we show that LOC100288798 is ubiquitously expressed, but inefficiently spliced. The minor spliced LOC100288798 isoforms are exported to the cytoplasm, whereas the major unspliced isoform is nuclear localized. This shows that LOC100288798 RNA biology differs markedly from typical mRNAs. De novo assembly from RNA-seq data suggests that LOC100288798 extends 289kb beyond its annotated 3'' end and overlaps the downstream SLC38A4 gene. Three cell lines with independent gene trap insertions in LOC100288798 were available from the KBM7 gene trap collection. RT-qPCR and RNA-seq confirmed successful lncRNA truncation and its extended length. Expression analysis from RNA-seq data shows significant deregulation of 41 protein-coding genes upon LOC100288798 truncation. Our data shows that gene trap collections in human haploid cell lines are useful tools to study lncRNAs, and identifies the previously uncharacterized LOC100288798 as a potential gene regulator. Overall design: We cultured and processed 8 KBM7 cell lines in one batch. These cell lines were: two wild type KBM7 cells (WT2 and WT3), two monoclonal KBM7 cell lines with gene trap cassette insertions outside of the body of LOC100288798 (C1 and C2), two independently obtained KBM7 clones with gene trap cassette insertion 3kb downstream LOC100288798 transcriptional start site (TSS) (3kb1 and 3kb2), one independently obtained KBM7 clone with gene trap cassette insertion 100kb downstream LOC100288798 TSS replicated twice at the thawing step (100kb1 and 100kb2). We isolated total RNA from all th 8 cell lines, applied DNAseI treatment and ribosomal RNA depletion, and thhen prepared strand-specific RNA-seq libraries, which were pooled in equal molarities and sequenced using Illumina HiSeq 2000 (8 pooled samples were sequence on 2 lanes). We performed 50bp single-end RNA-seq. We used these 8 samples (4 untreated: WT2, WT3, C1, C2 and 4 treated:3kb1, 3kb2, 100kbk1, 100kb2) to analyze genome-wide gene deregulation associated with LOC100288798 lncRNA truncation
A human haploid gene trap collection to study lncRNAs with unusual RNA biology.
No sample metadata fields
View SamplesPiwi proteins and Piwi-interacting small RNAs (piRNAs) have known functions in transposon silencing in the male germline of fetal and newborn mice. Both are also necessary for spermatogenesis in adult testes, however, their function here remains a mystery. Here, we use germ cell isolations and small RNA sequencing to show that most piRNAs in meiotic spermatocytes originate from clusters in intergenic non-repeat regions of DNA. The regulation of these piRNA clusters, including the processing of the precursor transcripts into individual piRNAs, is accomplished through mostly unknown processes. We present evidence for a regulatory mechanism for one such cluster, named cluster 1082B, located on chromosome 7 in the mouse genome, containing 788 unique piRNAs. The precursor transcript and individual piRNAs within the cluster are repressed by the Alkbh1 dioxygenase and the transcription repressor Tzfp, which are believed to be interaction partners in testis. We observe more than a thousand-fold upregulation of individual piRNAs in pachytene spermatocytes isolated from Alkbh1-/- and TzfpGTi/GTi testes. Repression is further supported by the identification of a 10 bp Tzfp recognition sequence contained within the precursor transcript. Downregulation of long interspersed elements 1 (LINE1) and intracisternal A-particle (IAP) transcripts in the Alkbh1-/- and TzfpGTi/GTi testes leads us to propose a potential role for the 1082B-encoded piRNAs in transposon silencing. Overall design: Characterization of small RNAs in mouse pachytene spermatocytes for wild-type (WT) and Alkbh1-/- and TzfpGTi/GTi, and mRNA in mouse pachytene spermatocytes for wild-type (WT) and Alkbh1-/-
Alkbh1 and Tzfp repress a non-repeat piRNA cluster in pachytene spermatocytes.
Specimen part, Subject
View SamplesSpinocerebellar ataxia type 3 (SCA3) is a dominantly inherited neurodegenerative disorder caused by a polyglutamine-encoding CAG repeat expansion in the ATXN3 gene, which encodes a deubiquitinating enzyme, ATXN3, implicated in numerous quality control pathways. Several mechanisms have been proposed to explain the pathogenic role of mutant polyQ-expanded ATXN3 in SCA3 including disease protein aggregation, impairment of ubiquitin-proteasomal degradation and transcriptional dysregulation. A better understanding of the normal functions of this protein may shed light on SCA3 disease pathogenesis. To assess the potential normal role of ATXN3 in regulating transcription, we compared gene expression profiles in wildtype (WT) versus Atxn3 knockout (KO) mouse embryonic fibroblasts (MEFs).
Loss of the Spinocerebellar Ataxia type 3 disease protein ATXN3 alters transcription of multiple signal transduction pathways.
Specimen part
View SamplesThe study examined early transcriptional changes in the brain of different mouse models of spinocerebellar ataxia type 3, a dominantly-inherited neurodegenerative disease caused by a CAG repeat expansion in the ATXN3 gene. The goal was to identify early transcriptional signatures that are strongly associated with the accumulation and aggregation of the disease protein, ataxin-3, in the brain. The study also investigated the extent to which the observed transcriptional changes might be contributors to disease pathogenesis. Overall design: The overall study includes multiple different RNA-seq runs utilizing wild-type, two different knock-in mouse models of SCA3 (a traditional and variant), two different transgenic models of SCA3 (Q84 and Q15), and an ataxin-3 knock-out mouse. In total, 19 wild-type mice, 13 homozygous variant knock-in mice, 6 heterozygous variant knock-in mice, 4 traditional homozygous knock-in mice, 4 traditional heterozygous knock-in mice, 4 Q84 transgenic mice, 4 Q15 transgenic mice, and 3 ataxin-3 knock-out mice. The majority of the study examined the pons of the mice, and with one smaller run examining the deep cerebellar nuclei of wild-type and variant homozygous knock-in mice (n=3 each).
Comparison of spinocerebellar ataxia type 3 mouse models identifies early gain-of-function, cell-autonomous transcriptional changes in oligodendrocytes.
Cell line, Subject
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