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Saccharomyces cerevisiae
31 Downloadable Samples
Illumina Genome Analyzer IIx, Illumina HiSeq 2500
Description
Antisense long non-coding (aslnc)RNAs represent a substantial part of eukaryotic transcriptomes that are, in yeast, controlled by the Xrn1 exonuclease. Nonsense-Mediated Decay (NMD) destabilizes the Xrn1-sensitive aslncRNAs (XUT), but what determines their sensitivity remains unclear. We report that 3’ single-stranded (3’-ss) extension mediates XUTs degradation by NMD, assisted by the Mtr4 and Dbp2 helicases. Single-gene investigation, genome-wide RNA analyses and double-stranded (ds)RNA mapping revealed that 3''-ss extensions discriminate the NMD-targeted XUTs from stable lncRNAs. Ribosome profiling showed that XUT are translated locking them for NMD activity. Interestingly, mutants of the Mtr4 and Dbp2 helicases accumulated XUTs, suggesting that dsRNA unwinding is a critical step for degradation. Indeed, expression of anti-complementary transcripts protects cryptic intergenic lncRNAs from NMD. Our results indicate that aslncRNAs form dsRNA that are only translated and targeted to NMD if dissociated by Mtr4 and Dbp2. We propose that NMD buffers genome expression by discarding pervasive regulatory transcripts. Overall design: Strand-specific transcriptome analysis of biological replicates (1) of WT and xrn1-delta cells of the S288C, W303 and SK1 (n & 2n) genetic background of S. cerevisiae; (2) of WT, dcp2-7 and upf1-delta cells; (3) of WT, xrn1-delta and dcp2-7 cells upon treatment of total RNA with Terminator 5''-Phosphate-Dependent Exonuclease. This record also contains CAGE-Seq analysis in wild-type and decapping-deficient cells of the budding yeast S. cerevisiae.
Publication Title
Nonsense-Mediated Decay Restricts LncRNA Levels in Yeast Unless Blocked by Double-Stranded RNA Structure.
Sample Metadata Fields
Subject
View Samples- Saccharomyces cerevisiae
- 6 Downloadable Samples
- Illumina HiSeq 2500
Description
GATA transcription factors are highly conserved among eukaryotes and play roles in transcription of genes implicated in cancer progression and hematopoiesis. However, although their consensus binding sites have been well defined in vitro, the in vivo selectivity for recognition by GATA factors remains poorly characterized. Using ChIP-Seq, we identified the Dal80 GATA factor targets in yeast. Our data reveal Dal80 binding to a large set of promoters, sometimes independently of GATA sites, correlating with nitrogen- and/or Dal80-sensitive gene expression. Strikingly, Dal80 was also detected across the body of promoter-bound genes, correlating with high expression. Mechanistic single-gene experiments showed that Dal80 spreading across gene bodies requires active transcription. Consistently, Dal80 co-immunoprecipitated with the initiating and post-initiation forms of RNA Polymerase II. Our work suggests that GATA factors could play dual, synergistic roles during transcription initiation and post-initiation steps, promoting efficient remodeling of the gene expression program in response to environmental changes. Overall design: Strand-specific total RNA-Seq analysis in wild-type (WT) and dal80-delta (dal80) cells grown in glutamine- and/or proline-containing medium.
Publication Title
Transcription-dependent spreading of the Dal80 yeast GATA factor across the body of highly expressed genes.
Sample Metadata Fields
Subject
View Samples
GSE18497- Homo sapiens
- 81 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Almost a quarter of pediatric patients with Acute Lymphoblastic Leukemia (ALL) suffer from relapses. The biological mechanisms underlying therapy response and development of relapses have remained unclear. In an attempt to better understand this phenomenon, we have analyzed 41 matched diagnosis relapse pairs of ALL patients using genomewide expression arrays (82 arrays) on purified leukemic cells. In roughly half of the patients very few differences between diagnosis and relapse samples were found (stable group), suggesting that mostly extra-leukemic factors (e.g., drug distribution, drug metabolism, compliance) contributed to the relapse. Therefore, we focused our further analysis on 20 samples with clear differences in gene expression (skewed group), reasoning that these would allow us to better study the biological mechanisms underlying relapsed ALL. After finding the differences between diagnosis and relapse pairs in this group, we identified four major gene clusters corresponding to several pathways associated with changes in cell cycle, DNA replication, recombination and repair, as well as B cell developmental genes. We also identified cancer genes commonly associated with colon carcinomas and ubiquitination to be upregulated in relapsed ALL. Thus, about half of relapses are due to selection or emergence of a clone with deregulated expression of a genes involved in pathways that regulate B cell signaling, development, cell cycle, cellular division and replication.
Publication Title
Genome-wide expression analysis of paired diagnosis-relapse samples in ALL indicates involvement of pathways related to DNA replication, cell cycle and DNA repair, independent of immune phenotype.
Sample Metadata Fields
Sex, Specimen part, Disease
View Samples- Homo sapiens
- 19 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Hodgkin's lymphoma (HL) is one of the most frequent hematological malignancies. Due to its extraordinary composition, few tumor cells surrounded by a reactive infiltrate, HL can be seen as an ideal model system for research focusing on tumor immunology. In fact, the tumor cells of HL, so called Hodgkin/Reed-Sternberg (HRS) cells attract CD4+ T cells, which then build rosettes with the HRS cells. HRS cells further modulate the tumor microenvironment with the help of CD4+ T cells to avoid tumor rejection. Here, we mimicked this scenario using compatible CD4+ T cells receiveing data of profound interactions for the first time, as former studies were performed with allogeneic donors. Finally, we genetically retargeted compatible CD4+ T cells to kill HRS cells.
Publication Title
Tumor-infiltrating HLA-matched CD4(+) T cells retargeted against Hodgkin and Reed-Sternberg cells.
Sample Metadata Fields
Cell line
View Samples- Homo sapiens
- 80 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
Individuals with Down syndrome (DS) are predisposed to develop acute megakaryoblastic leukemia (AMKL), characterized by expression of truncated GATA1 transcription factor protein (GATA1s) due to somatic mutation. The treatment outcome for DS-AMKL is more favorable than for AMKL in non-DS patients. To gain insight into gene expression differences in AMKL, we compared 24 DS and 39 non-DS AMKL samples. We found that non-DS-AMKL samples cluster in two groups, characterized by differences in expression of HOX/TALE family members. Both of these groups are distinct from DS-AMKL, independent of chromosome 21 gene expression. To explore alterations of the GATA1 transcriptome, we used cross-species comparison with genes regulated by GATA1 expression in murine erythroid precursors. Genes repressed after GATA1 induction in the murine system, most notably GATA-2, MYC, and KIT, show increased expression in DS-AMKL, suggesting that GATA1s fail to repress this class of genes. Only a subset of genes that are up-regulated upon GATA1 induction in the murine system show increased expression in DS-AMKL, including GATA1 and BACH1, a probable negative regulator of megakaryocytic differentiation located on chromosome 21. Surprisingly, expression of the chromosome 21 gene RUNX1, a known regulator of megakaryopoiesis, was not elevated in DS-AMKL. Our results identify relevant signatures for distinct AMKL entities and provide insight into gene expression changes associated with these related leukemias.
Publication Title
Identification of distinct molecular phenotypes in acute megakaryoblastic leukemia by gene expression profiling.
Sample Metadata Fields
Sex, Age
View Samples- Homo sapiens
- 10 Downloadable Samples
- IlluminaHiSeq2000
Description
Biochemical fractionation of HEK293 nuclei and RNA-seq of chromatin-associated and soluble-nuclear RNA. Overall design: Nuclei from three biological replicates were isolated by detergent lysis, fractionated, then three chromatin and three soluble RNA samples were converted to cDNA using Illumina TruSeq stranded protocol, and sequenced on Illumina HiSeq2000
Publication Title
Nuclear Fractionation Reveals Thousands of Chromatin-Tethered Noncoding RNAs Adjacent to Active Genes.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 92 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
T-cell acute lymphoblastic leukemia (T-ALL) is mostly characterized by specific chromosomal abnormalities, some occurring in a mutually exclusive manner possibly delineating specific T-ALL subgroups. One subgroup, including MLL-rearranged, CALM-AF10 or inv(7)(p15q34) cases, is characterized by elevated expression of HOXA genes. Using a gene expression based clustering analysis of 67 T-ALL cases with recurrent molecular genetic abnormalities and 25 samples lacking apparent aberrations, we identified 5 new cases with elevated HOXA levels. Using array-CGH, a cryptic and recurrent deletion, del(9)(q34.11q34.13), was exclusively identified in 3 of these 5 cases. This deletion results in a conserved SET-NUP214 fusion product, that was also identified in the T-ALL cell line LOUCY. SET-NUP214 binds in the promoter regions of specific HOXA genes, where it may interact with CRM1 and DOT1L leading to the transcriptional activation of HOXA genes. Targeted inhibition of SET-NUP214 by siRNA abolished expression of HOXA genes, inhibited proliferation and induced differentiation in LOUCY but not in other T-ALL lines. We conclude that SET-NUP214 may contribute to the pathogenesis of T-ALL by enforcing T-cell differentiation arrest.
Publication Title
The recurrent SET-NUP214 fusion as a new HOXA activation mechanism in pediatric T-cell acute lymphoblastic leukemia.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 213 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Pediatric acute myeloid leukemia (AML) is a heterogeneous disease characterized by non-random genetic aberrations related to outcome. Detecting these aberrations however still lead to failures or false negative results. Therefore, we focused on the potential of gene expression profiles (GEP) to classify pediatric AML.
Publication Title
Evaluation of gene expression signatures predictive of cytogenetic and molecular subtypes of pediatric acute myeloid leukemia.
Sample Metadata Fields
Specimen part, Subject
View Samples- Homo sapiens
- 24 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
The Rac nucleotide Exchange Factor (Rac-GEF) P-Rex1 is highly expressed in breast cancer, specifically in the luminal subtype, and is an essential mediator of actin cytoskeleton reorganization and cell migratory responses induced by ErbB and other tyrosine-kinase receptors. Heregulin, a growth factor highly expressed in mammary tumors, causes the activation of P-Rex1 and Rac1 in breast cancer cells via ErbB3, leading to a motile response. Since there is limited information about P-Rex1 downstream effectors, we carried out a microarray analysis to identify genes regulated by P-Rex1 in the context of HRG stimulation. In T-47D breast cancer cells, HRG treatment caused major changes in gene expression, including genes associated with motility, adhesion, invasiveness and metastasis. Silencing P-Rex1 expression from T-47D cells using RNAi altered the induction and repression of a subset of HRG-regulated genes, among them genes associated with extracellular matrix organization, migration, and chemotaxis. HRG induction of MMP10, a gene encoding for metalloproteinase-10, was found to be highly sensitive both to P-Rex1 depletion as well as inhibition of Rac1 function by the GTPase Activating Protein (GAP) 2-chimaerin, suggesting the dependence of the P-Rex1/Rac1 pathway for the induction of genes critical for breast cancer invasiveness. Notably, there is a significant association in the expression of P-Rex1 and MMP10 in human luminal breast cancer, and their co-expression is indicative of poor prognosis.
Publication Title
Characterization of a P-Rex1 gene signature in breast cancer cells.
Sample Metadata Fields
No sample metadata fields
View Samples- Drosophila melanogaster
- 16 Downloadable Samples
- Affymetrix Drosophila Genome 2.0 Array (drosophila2)
Description
The rapid evolution of toxin resistance in animals has important consequences for the ecology of species and our economy. Pesticide resistance in insects has been a subject of intensive study, however, very little is known about how Drosophila species became resistant to natural toxins with ecological relevance, such as -amanitin that is produced in deadly poisonous mushrooms. Here we performed a microarray study to elucidate the genes, chromosomal loci, molecular functions, biological processes, and cellular components that contribute to the -amanitin resistance phenotype in Drosophila melanogaster. We suggest that toxin entry blockage through the cuticle, phase I and II detoxification, sequestration in lipid particles, and proteolytic cleavage of -amanitin contribute in concert to this quantitative trait. We speculate that the resistance to mushroom toxins in Drosophila melanogaster and perhaps in mycophagous Drosophila species has evolved as a cross-resistance to pesticides or other xenobiotic substances.
Publication Title
The mechanisms underlying α-amanitin resistance in Drosophila melanogaster: a microarray analysis.
Sample Metadata Fields
Specimen part
View Samples