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GSE54483
Homo sapiens
10 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Sadanandam et al. (2013) recently published a study based on the use of microarray data to classify colorectal cancer (CRC) samples. The classification claimed to have strong clinical implications, as reflected in the paper title: A colorectal cancer classification system that associates cellular phenotype and responses to therapy. They defined five subtypes: (i) inflammatory; (ii) goblet-like; (iii) enterocyte; (iv) transit-amplifying; and (v) stem-like. Based on drug sensitivity data from 21 patients, they also reported that the so-called stem-like subtype show differential sensitivity to FOLFIRI. This is the key result in their publication, since it implies a direct relation between the subtype and the choice of CRC therapy (i.e. FOLFIRI response). However, our analyses using the same drug sensitivity data and results from additional patients showed that the CRC classification reported by Sadanandam et al. is not predictive of FOLFIRI response.
Publication Title
Colorectal cancer classification based on gene expression is not associated with FOLFIRI response.
Sample Metadata Fields
Specimen part
View Samples- Danio rerio
- 17 Downloadable Samples
IlluminaGenomeAnalyzerII, IlluminaHiSeq2000
Description
Long non-coding RNAs (lncRNAs) comprise a diverse class of transcripts that structurally resemble mRNAs but do not encode proteins. Recent genome-wide studies in human and mouse have annotated lncRNAs expressed in cell lines and adult tissues, but a systematic analysis of lncRNAs expressed during vertebrate embryogenesis has been elusive. To identify lncRNAs with potential functions in vertebrate embryogenesis, we performed a time series of RNA-Seq experiments at eight stages during early zebrafish development. We reconstructed 56,535 high-confidence transcripts in 28,912 loci, recovering the vast majority of expressed RefSeq transcripts, while identifying thousands of novel isoforms and expressed loci. We defined a stringent set of 1,133 non-coding multi-exonic transcripts expressed during embryogenesis. These include long intergenic ncRNAs (lincRNAs), intronic overlapping lncRNAs, exonic antisense overlapping lncRNAs, and precursors for small RNAs (sRNAs). Zebrafish lncRNAs share many of the characteristics of their mammalian counterparts: relatively short length, low exon number, low expression, and conservation levels comparable to introns. Subsets of lncRNAs carry chromatin signatures characteristic of genes with developmental functions. The temporal expression profile of lncRNAs revealed two novel properties: lncRNAs are expressed in narrower time windows than protein-coding genes and are specifically enriched in early-stage embryos. In addition, several lncRNAs show tissue-specific expression and distinct subcellular localization patterns. Integrative computational analyses associated individual lncRNAs with specific pathways and functions, ranging from cell cycle regulation to morphogenesis. Our study provides the first comprehensive identification of lncRNAs in a vertebrate embryo and forms the foundation for future genetic, genomic and evolutionary studies. Overall design: RNA-Seq for 8 zebrafish developmental stages, 2 lanes for each stage (3 for shield).
Publication Title
Ribosome profiling reveals resemblance between long non-coding RNAs and 5' leaders of coding RNAs.
Sample Metadata Fields
No sample metadata fields
View Samples- Pseudomonas aeruginosa pao1, Pseudomonas aeruginosa
- 16 Downloadable Samples
- Affymetrix Pseudomonas aeruginosa Array (paeg1a)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Novel targets of the CbrAB/Crc carbon catabolite control system revealed by transcript abundance in Pseudomonas aeruginosa.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 12 Downloadable Samples
- Illumina HumanHT-12 V4.0 expression beadchip
Description
We previously identified the ZTRE in genes involved in zinc homeostasis and showed that it mediates transcriptional repression in response to zinc. We now report that ZNF658 acts at the ZTRE. ZNF658 was identified by MALDI-TOF mass spectrometry of a band excised after EMSA using a ZTRE probe. The protein contains a KRAB domain and 21 zinc fingers. It has similarity with ZAP1 from Saccharomyces cerevisiae, which regulates the response to zinc restriction, including a conserved DNA binding region we show to be functional also in ZNF658. siRNA targeted to ZNF658 abrogated the zinc-induced, ZTRE-dependent reduction in SLC30A5 (ZnT5), SLC30A10 (ZnT10) and CBWD transcripts in human Caco-2 cells and the ability of zinc to repress reporter gene expression from corresponding promoter-reporter constructs. Microarray analysis of the effect of reducing ZNF658 expression by siRNA uncovered large changes in rRNA. We find that ZTREs are clustered within the 45S rRNA precursor. We also saw effects on expression of multiple ribosomal proteins. ZNF658 thus links zinc homeostasis with ribosome biogenesis, the most active transcriptional, and hence zinc-demanding, process in the cell. ZNF658 is thus a novel transcriptional regulator that plays a fundamental role in the orchestrated cellular response to zinc availability.
Publication Title
The zinc finger protein ZNF658 regulates the transcription of genes involved in zinc homeostasis and affects ribosome biogenesis through the zinc transcriptional regulatory element.
Sample Metadata Fields
Cell line
View Samples- Drosophila melanogaster
- 10 Downloadable Samples
- NextSeq 550, Illumina HiSeq 2500
Description
The Drosophila wing disc has been a fundamental model system for the discovery of key signaling pathways and for our understanding of developmental processes. However, a complete map of gene expression in this tissue is lacking. To obtain a complete gene expression atlas in the wing disc, we employed single-cell sequencing (scRNA-seq) and developed a new method for analyzing scRNA-seq data based on gene expression correlations rather than cell mappings. This enables us to discover 824 genes with spatially restricted expression patterns, and to compute expression maps for all genes in the wing disc. This approach identifies both known and new clusters of genes with similar expression patterns and functional relevance. As proof of concept, we characterize the previously unstudied gene CG5151 and show it regulates Wnt signaling. This novel method will enable the leveraging of scRNA-seq data for generating expression atlases of undifferentiated tissues during development. Overall design: Single cell transcriptome experiments from female wandering 3rd instar wing discs were generated: two samples using Drop-seq and one sample using the 10x genomics platform. Bulk polyA-RNA-seq experiment from the same tissue was conducted for comparison.
Publication Title
Gene expression atlas of a developing tissue by single cell expression correlation analysis.
Sample Metadata Fields
Sex, Specimen part, Subject
View Samples- Danio rerio
- 8 Downloadable Samples
- IlluminaHiSeq2000
Description
To experimentally-validate the non-coding status of annotated lncRNAs, we performed ribosome profiling over a developmental timecourse that matched our previously-published (Pauli et al. 2012) developmental transcriptome. We find that many previously-annotated lncRNAs appear to be translated, but in a pattern more akin to 5'' leaders of coding genes. Overall design: Ribosome profiling over 8 stages in early zebrafish development: 2-4 cell, 256 cell, 1K cell, Dome, Shield, Bud, 28hpf and 5dpf
Publication Title
Ribosome profiling reveals resemblance between long non-coding RNAs and 5' leaders of coding RNAs.
Sample Metadata Fields
No sample metadata fields
View Samples- Pseudomonas aeruginosa pao1, Pseudomonas aeruginosa
- 8 Downloadable Samples
- Affymetrix Pseudomonas aeruginosa Array (paeg1a)
Description
The opportunistic human pathogen Pseudomonas aeruginosa can utilize several carbon and nitrogen compounds as energy sources, which allows the bacterium to grow on a variety of different environments. Nevertheless, the uptake and utilization of these compounds is organized in a hierarchical manner, which is guaranteed by a mechanism named catabolite repression. In P. aeruginosa catabolite repression is a post-transcriptional process with the translational repressor protein, Crc, as the main component. Crc recognizes CA-motifs (acronym for catabolite activity) present in the vicinity of the ribosome binfing site of corresponding target mRNAs and therefore compete with ribosome binding. Certain conditions, which are mainly related to changes in the carbon to nitrogen ratio, induce the two component system CbrAB, which activates the transcription of the sRNA CrcZ. The sRNA sequesters Crc and allows the translation of the target mRNAs. The main focus of this study was to identify novel direct targets of the CbrAB/Crc system with the use of a transcriptome analysis in combination with the search for CA-motifs. We were able to identify five novel targets (estA, acsA, dctP, bkdR and aroP2), which were involved in the uptake and utilization of less preferred carbon sources and amino acids. Direct interaction of Crc with these genes and the resulting regulation by CbrB and CrcZ were verified using mutational analysis and in vitro and in vivo experiments. Moreover, these targets were discussed in the light of growth and biofilm development in synthetic CF sputum medium which emphasised the importance of the CbrAB/Crc system as a regulator of chronic infection.
Publication Title
Novel targets of the CbrAB/Crc carbon catabolite control system revealed by transcript abundance in Pseudomonas aeruginosa.
Sample Metadata Fields
No sample metadata fields
View Samples- Pseudomonas aeruginosa pao1, Pseudomonas aeruginosa
- 8 Downloadable Samples
- Affymetrix Pseudomonas aeruginosa Array (paeg1a)
Description
The opportunistic human pathogen Pseudomonas aeruginosa can utilize several carbon and nitrogen compounds as energy sources, which allows the bacterium to grow on a variety of different environments. Nevertheless, the uptake and utilization of these compounds is organized in a hierarchical manner, which is guaranteed by a mechanism named catabolite repression. In P. aeruginosa catabolite repression is a post-transcriptional process with the translational repressor protein, Crc, as the main component. Crc recognizes CA-motifs (acronym for catabolite activity) present in the vicinity of the ribosome binfing site of corresponding target mRNAs and therefore compete with ribosome binding. Certain conditions, which are mainly related to changes in the carbon to nitrogen ratio, induce the two component system CbrAB, which activates the transcription of the sRNA CrcZ. The sRNA sequesters Crc and allows the translation of the target mRNAs. The main focus of this study was to identify novel direct targets of the CbrAB/Crc system with the use of a transcriptome analysis in combination with the search for CA-motifs. We were able to identify five novel targets (estA, acsA, dctP, bkdR and aroP2), which were involved in the uptake and utilization of less preferred carbon sources and amino acids. Direct interaction of Crc with these genes and the resulting regulation by CbrB and CrcZ were verified using mutational analysis and in vitro and in vivo experiments. Moreover, these targets were discussed in the light of growth and biofilm development in synthetic CF sputum medium which emphasised the importance of the CbrAB/Crc system as a regulator of chronic infection.
Publication Title
Novel targets of the CbrAB/Crc carbon catabolite control system revealed by transcript abundance in Pseudomonas aeruginosa.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 15 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Neuroblastomas are tumors of the developing peripheral sympathetic nervous system, which originates from the neural crest. Twenty percent of neuroblastomas show amplification of the MYCN oncogene, which correlates with poor prognosis. The MYCN transcription factor can activate and repress gene expression. To broaden our insight in the spectrum of genes down-regulated by MYCN, we generated gene expression profiles of the neuroblastoma cell lines SHEP-21N and SKNAS-NmycER, in which MYCN activity can be regulated. In this study, we show that MYCN suppresses the expression of Dickkopf-1 (DKK1) in both cell lines. DKK1 is a potent inhibitor of the wnt/beta-catenin signalling cascade, which is known to function in neural crest cell migration. We generated a DKK1 inducible cell line, IMR32-DKK1, which showed impaired proliferation upon DKK1 expression. Surprisingly, DKK1 expression did not inhibit the canonical wnt/beta-catenin signalling, suggesting a role of DKK1 in an alternative route of the wnt pathway. Gene expression profiling of two IMR32-DKK1 clones showed that only a few genes, amongst which SYNPO2, were up-regulated by DKK1. SYNPO2 encodes an actin-binding protein and was previously found to inhibit proliferation and invasiveness of prostate cancer cells. These results suggest that MYCN might stimulate cell proliferation by inhibiting the expression of DKK1. DKK1 might exert part of its growth suppressive effect by induction of SYNPO2 expression.
Publication Title
Dickkopf-1 is down-regulated by MYCN and inhibits neuroblastoma cell proliferation.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 6 Downloadable Samples
- Illumina HiSeq 2500
Description
p21-activated kinases (Paks) play an important role in oncogenic signaling pathways, and have therefore been considered as potential therapeutic targets in various cancers. Most studies of Pak function employ loss of function methods such as gene knock-out or knock-down, but these approaches result in loss of both the enzymatic and scaffolding properties of these proteins, and thus may not reflect the effects of small molecule inhibitors that block catalytic function. In this study we use a new transgenic mouse model in which a specific peptide inhibitor of Group I Paks (Pak1, -2, and -3) is conditionally expressed in response to Cre recombinase. Using this model, we show that inhibition of endogenous Pak function impedes the transition of adenoma to carcinoma in an Apc-driven mouse model of colorectal cancer. These effects are mediated by inhibition of Wnt signaling through reduced ß-catenin activity as well as suppression of an epithelial-mesenchymal transition program mediated by miR-200 and Snai1. These results highlight the potential therapeutic role of Pak1 inhibitors in colorectal cancer and suggest new therapeutic strategies in this disease. Overall design: We generated a targeted transgenic mouse carrying a conditionally activated PID allele at the Rosa26 locus, and showed that expression of this allele effectively inhibited the activity of Group I Paks in vivo. To assess the global molecular effects of Pak inhibition in Apc-null CRC cells, we next explored the effect of repressing Pak activity on transcription. Total RNA was extracted from PID+ and PID- cells and RNA-sequencing was preformed, followed by pathway analysis and qPCR validation for selected mRNAs.
Publication Title
Group I Paks are essential for epithelial- mesenchymal transition in an Apc-driven model of colorectal cancer.
Sample Metadata Fields
Treatment, Subject
View Samples