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GSE15102
Homo sapiens
8 Downloadable Samples
Affymetrix Human Genome U133A 2.0 Array (hgu133a2)
Description
CD24 is a potential oncogene reported to be overexpressed in a large variety of human malignancies. We have shown that CD24 is overexpressed in 90% of colorectal tumors at a fairly early stage in the multistep process of carcinogenesis. Anti-CD24 monoclonal antibodies (mAb) induce a significant growth inhibition in colorectal and pancreatic cancer cell lines that express the protein. This study is designed to investigate further the effects of CD24 down-regulation using mAb or small interfering RNA in vitro and in vivo. Western blot analysis showed that anti-CD24 mAb induced CD24 protein down-regulation through lysosomal degradation. mAb augmented growth inhibition in combination with five classic chemotherapies. Xenograft models in vivo showed that tumor growth was significantly reduced in mAb-treated mice. Similarly, stable growth inhibition of cancer cell lines was achieved by down-regulation of CD24 expression using short hairpin RNA (shRNA). The produced clones proliferated more slowly, reached lower saturation densities, and showed impaired motility. Most importantly, down-regulation of CD24 retarded tumorigenicity of human cancer cell lines in nude mice. Microarray analysis revealed a similar pattern of gene expression alterations when cells were subjected to anti-CD24 mAb or shRNA. Genes in the Ras pathway, mitogenactivated protein kinase, or BCL-2 family and others of oncogenic association were frequently down-regulated. As a putative new oncogene that is overexpressed in gastrointestinal malignancies early in the carcinogenesis process, CD24 is a potential target for early intervention in the prevention and treatment of cancer.
Publication Title
Targeting CD24 for treatment of colorectal and pancreatic cancer by monoclonal antibodies or small interfering RNA.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Mus musculus
- 28 Downloadable Samples
- Affymetrix Murine Genome U74A Version 2 Array (mgu74av2)
Description
Nicotine, acting through the neuronal nicotinic acetylcholine receptors (nAChR), can induce seizures in mice. We aimed to study brain transcriptional response to seizure and to identify genes whose expression is altered after nicotine-induced seizures. Whole brains of untreated mice were compared to brains one hour after seizure activity, using Affymetrix U74Av2 microaarays. Experimental groups included wild-type mice and both nicotine-induced seizures sensitive and resistant nAChR mutant mice. Each genotype group received different nicotine doses to generate seizures. This approach allowed the identification of significantly changed genes whose expression was dependent on seizure activity, nicotine administration or both, but not on the type of nAChR subunit mutation or the amount of nicotine injected. Significant expression changes were detected in 62 genes (p < 0.05, FDR correction). Among them, GO functional annotation analysis determined that the most significantly over-represented categories were of genes encoding MAP kinase phosphatases, regulators of transcription and nucleosome assembly proteins. In-silico bioinformatic analysis of the promoter regions of the 62 changed genes detected the significant enrichments of 16 transcription regulatory elements (TREs), creating a network of transcriptional regulatory responses to seizures. The TREs for ATF and SRF were most significantly enriched, supporting their association with seizure activity. Our data suggest that nicotine-induced seizure in mice is a useful model to study seizure activity and its global brain transcriptional response. The differentially expressed genes detected here can help understand the molecular mechanisms underlying seizures in animal models, and may also serve as candidate genes to study epilepsy in humans.
Publication Title
Expression changes in mouse brains following nicotine-induced seizures: the modulation of transcription factor networks.
Sample Metadata Fields
Sex, Age, Treatment
View Samples- Mus musculus
- 20 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Aging is accompanied by expression changes in multiple genes and the brain is one of the tissues most vulnerable to aging. Since the alpha7 nicotinic acetylcholine receptor (nAChR) subunit has been associated with neurodevelopmental disorders and cognitive decline during aging, we hypothesized that its absence might affect gene expression profiles in aged brains. To study whether transcriptional changes occur due to aging, alpha7 deficiency or both, we analyzed whole brain transcriptomes of young (8 week) and aged (2 year) alpha7 deficient and wild-type control mice, using Mouse Genome 430 2.0 microarray. Highly significant expression changes were detected in 47 and 1543 genes (after Bonferroni and FDR correction) in the brains of aged mice compared to young mice, regardless of their genotype. These included genes involved in immune system function and ribosome structure, as well as genes that were previously demonstrated as differentially expressed in aging human brains. Genotype-dependent changes were detected in only 3 genes, Chrna7 which encodes the alpha7 nAChR subunit, and two closely linked genes, likely due to a mouse background effect. Expression changes dependent on age-genotype interaction were detected in 207 genes (with a low significance threshold). Age-dependent differential expression levels were approved in all nine genes that were chosen for validation by real-time RT-PCR. Our results suggest that the robust effect of aging on brain transcription clearly overcomes the almost negligible effect of alpha7 nAChR subunit deletion, and that germline deficiency of this subunit has a minor effect on brain expression profile in aged mice.
Publication Title
The effects of aging vs. α7 nAChR subunit deficiency on the mouse brain transcriptome: aging beats the deficiency.
Sample Metadata Fields
Age
View Samples- Homo sapiens
- 558 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Establishing reliable biomarkers for assessing and validating clinical diagnosis at early prodromal stages of Parkinsons disease is crucial for developing therapies to slow or halt disease progression. Here, we present the largest study to date using whole blood gene expression profiling from over 500 individuals to identify an 87-gene blood-based signature. Our gene signature effectively differentiates between idiopathic PD patients and controls in both a validation cohort and an independent test cohort, and further highlights mitochondrial metabolism and ubiquitination/proteasomal degradation as potential pathways disrupted in Parkinsons disease.
Publication Title
Analysis of blood-based gene expression in idiopathic Parkinson disease.
Sample Metadata Fields
Sex, Specimen part, Subject
View Samples- Homo sapiens
- 75 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
The cellular response to DNA damage is vital for maintaining genomic stability and preventing undue cell death or cancer formation. The DNA damage response (DDR), most robustly mobilized by double-strand breaks (DSBs), rapidly activates an extensive signaling network that affects numerous cellular systems, leading to cell survival or programmed cell death. A major component of the DDR is the widespread modulation of gene expression. We analyzed transcriptional responses to ionizing radiation (IR) in 5 human cell lines to elucidate the scope of this response and identify its gene targets. According to the mRNA expression profiles most of the responses were cell line-specific. Data analysis identified significant enrichment for p53 target genes and cell cycle-related pathways among groups of up-regulated and down-regulated genes, respectively.
Publication Title
Transcriptional modulation induced by ionizing radiation: p53 remains a central player.
Sample Metadata Fields
Cell line, Time
View Samples- Homo sapiens
- 15 Downloadable Samples
- Affymetrix Human Gene 1.1 ST Array (hugene11st), Illumina HumanHT-12 V4.0 expression beadchip
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
No associated publication
Sample Metadata Fields
Specimen part, Disease, Cell line, Treatment
View Samples- Mus musculus
- 30 Downloadable Samples
- Affymetrix HT Mouse Genome 430A Array (htmg430a)
Description
Individual genetic variation affects gene expression and cell phenotype by acting within complex molecular circuits, but this relationship is still largely unknown. Here, we combine genomic and meso-scale profiling with novel computational methods to detect genetic variants that affect the responsiveness of gene expression to stimulus (responsiveness QTLs) and position them in circuit diagrams. We apply this approach to study individual variation in transcriptional responsiveness to three different pathogen components in the model response of primary bone marrow dendritic cells (DCs) from recombinant inbred mice strains. We show that reQTLs are common both in cis (affecting a single target gene) and in trans (pleiotropically affecting co-regulated gene modules) and are specific to some stimuli but not others. Leveraging the stimulus-specific activity of reQTLs and the differential responsiveness of their associated targets, we show how to position reQTLs within the context of known pathways in this regulatory circuit. For example, we find that a pleiotropic trans-acting genetic factor in chr1:129-165Mb affects the responsiveness of 35 anti-viral genes only during an anti-viral like stimulus. Using RNAi we uncover RGS16 the likely causal gene in this interval, and an activator of the antiviral response. Our approach charts an experimental and analytic path to decipher the mechanisms underlying genetic variation in other complex circuits in primary mammalian cells.
Publication Title
Deciphering molecular circuits from genetic variation underlying transcriptional responsiveness to stimuli.
Sample Metadata Fields
Age, Specimen part
View Samples- Homo sapiens
- 24 Downloadable Samples
Affymetrix Human Genome U133A 2.0 Array (hgu133a2), Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
PrtT-regulated proteins secreted by Aspergillus fumigatus activate MAPK signaling in exposed A549 lung cells leading to necrotic cell death.
Sample Metadata Fields
Specimen part, Cell line, Treatment
View Samples- Mus musculus
- 22 Downloadable Samples
- Affymetrix Mouse Clariom S Array (clariomsmouse)
Description
Our data mark GIP as a beneficial immunoregulator during obesity and suggest a novel untapped therapeutic potential for specific targeted GIP analogs.
Publication Title
Glucose-Dependent Insulinotropic Polypeptide Receptor Deficiency Leads to Impaired Bone Marrow Hematopoiesis.
Sample Metadata Fields
Sex, Specimen part
View Samples- Homo sapiens
- 20 Downloadable Samples
- Affymetrix Human Gene 2.1 ST Array (hugene21st)
Description
Identification of filamin-A as a target for insulin and IGF1 action.
Publication Title
Genome-Wide Analyses Identify Filamin-A As a Novel Downstream Target for Insulin and IGF1 Action.
Sample Metadata Fields
Cell line, Treatment
View Samples