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GSE18632
Homo sapiens
7 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
TDP-43 is an RNA/DNA-binding protein implicated in transcriptional repression and mRNA processing. Inclusions of TDP-43 are hallmarks of frontotemporal dementias and amyotrophic lateral sclerosis. Besides aggregation of TDP-43, loss of nuclear localization is observed in disease. To identify relevant targets of TDP-43, we performed an expression profiling study. Thereby, histone deacetylase 6 (HDAC6) downregulation was discovered upon TDP-43 silencing on mRNA and protein level in human embryonic kidney HEK293E and neuronal SH-SY5Y cells. This was accompanied by accumulation of the major HDAC6 substrate, acetyl-tubulin. Expression of wild-type but neither RNA-binding- nor nuclear-localization-deficient TDP-43 restored HDAC6 expression. Moreover, TDP-43 bound specifically to HDAC6 mRNA arguing for a direct functional interaction. Importantly, in vivo validation in TDP-43 knockout Drosophila melanogaster also showed HDAC6 mRNA decrease. HDAC6 is necessary for protein aggregate formation and degradation. Indeed, downregulation of HDAC6 reduced aggregate formation and increased cytotoxicity of expanded poly-glutamine ataxin-3 in TDP-43 silenced cells. This was completely restored by co-transfection with HDAC6. In conclusion, loss of functional TDP-43 causes HDAC6 downregulation and might thereby contribute to pathogenesis.
Publication Title
Knockdown of transactive response DNA-binding protein (TDP-43) downregulates histone deacetylase 6.
Sample Metadata Fields
Cell line
View Samples- Homo sapiens
- 4 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Efficient processing of target antigens by the ubiquitin-proteasome-system (UPS) is essential for treatment of cancers by T cell therapies. However, immune escape due to impaired expression of IFN--inducible components of the antigen presentation machinery and consequent inefficient processing of HLA-dependent tumor epitopes can be one important reason for failure of such therapies. Here, we show that repeated short-term co-cultures of Melan-A/MART-1 tumor antigen-expressing melanoma cells with Melan-A/MART-1 (26-35)-specific CTL led to the generation of clones resistant to CTL-mediated cell death. To determine which of the UPS components and its associated pathways was responsible for CTL escape; three UKRV-Mel-15a clones were subjected to microarray gene expression analysis.
Publication Title
Exposure to Melan-A/MART-126-35 tumor epitope specific CD8(+)T cells reveals immune escape by affecting the ubiquitin-proteasome system (UPS).
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 24 Downloadable Samples
- Affymetrix Murine Genome U74A Version 2 Array (mgu74av2)
Description
Attainment of a brown adipocyte cell phenotype in white adipocytes, with their abundant mitochondria and increased energy expenditure potential, is a legitimate strategy for combating obesity. The unique transcriptional regulators of the primary brown adipocyte phenotype are unknown, limiting our ability to promote brown adipogenesis over white. In the present work, we used microarray analysis strategies to study primary preadipocytes, and we made the striking discovery that brown preadipocytes demonstrate a myogenic transcriptional signature, whereas both brown and white primary preadipocytes demonstrate signatures distinct from those found in immortalized adipogenic models. We found a plausible SIRT1-related transcriptional signature during brown adipocyte differentiation that may contribute to silencing the myogenic signature. In contrast to brown preadipocytes or skeletal muscle cells, white preadipocytes express Tcf21, a transcription factor that has been shown to suppress myogenesis and nuclear receptor activity. In addition, we identified a number of developmental genes that are differentially expressed between brown and white preadipocytes and that have recently been implicated in human obesity. The interlinkage between the myocyte and the brown preadipocyte confirms the distinct origin for brown versus white adipose tissue and also represents a plausible explanation as to why brown adipocytes ultimately specialize in lipid catabolism rather than storage, much like oxidative skeletal muscle tissue.
Publication Title
Myogenic gene expression signature establishes that brown and white adipocytes originate from distinct cell lineages.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 108 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
In this study that was specifically designed to identify early stages of glaucoma in DBA/2J mice, we used genome-wide expression profiling and a series of computational methods. Our methods successfully subdivided eyes with no detectable glaucoma by conventional assays into molecularly defined stages of disease. These stages represent a temporally ordered sequence of glaucoma states. Using an array of tools, we then determined networks and biological processes that are altered at these early stages. Our strategy proved very sensitive, suggesting that similar approaches will be valuable for uncovering early processes in other complex, later-onset diseases. Early changes included upregulation of both the complement cascade and endothelin system, and so we tested the therapeutic value of separately inhibiting them. Mice with a mutation in the complement component 1a gene (C1qa) were robustly protected from glaucoma with the protection being among the greatest reported. Similarly, inhibition of the endothelin system was strongly protective. Since EDN2 is potently vasoconstrictive and was produced by microglial/macrophages, our data provide a novel link between these cell types and vascular dysfunction in glaucoma. Targeting early events such as the upregulation of the complement and endothelin pathways may provide effective new treatments for human glaucoma.
Publication Title
Molecular clustering identifies complement and endothelin induction as early events in a mouse model of glaucoma.
Sample Metadata Fields
Sex, Age, Specimen part
View Samples- Homo sapiens
- 11 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
The overarching goal of this study was to explore the antitumor activity of Z-endoxifen, a tamoxifen metabolite, with first-line endocrine therapies tamoxifen and letrozole in the letrozole-sensitive MCF7 aromatase expressing model (MCF7AC1), and with second-line endocrine therapies including tamoxifen, fulvestrant, exemestane, and exemestane plus everolimus, in letrozole-resistant MCF7 model (MCF7LR) in vivo.
Publication Title
Antitumor activity of Z-endoxifen in aromatase inhibitor-sensitive and aromatase inhibitor-resistant estrogen receptor-positive breast cancer.
Sample Metadata Fields
Cell line, Treatment
View Samples- Rattus norvegicus
- 4 Downloadable Samples
- Affymetrix Rat Expression 230A Array (rae230a)
Description
Previous studies have shown that treatment with the somatostatin analogue octreotide LAR causes regression of gastric ECL-cell carcinoids in patients with hypergastrinaemia due to chronic atrophic gastritis, reducing both the number and size of tumours. The main objective of the present study was to examine the molecular mechanisms behind the antiproliferative effect of octreotide in the oxyntic mucosa on a genome wide scale. Female Sprague-Dawley rats were dosed with octreotide LAR and control group were given the LAR vehicle for 21 days. Serum gastrin levels were measured and tissue samples for histology and RNA extraction collected from the oxyntic mucosa. Histomorphological examination showed a significant decrease in the number of gastric glands, cells per gland and length of glands, indicating a negative effect of octreotide on growth of the oxyntic mucosa. Further immunohistochemical studies showed a tendency towards increased apoptosis and decreased proliferation in the group receiving octreotide. Affymetrix GeneChip microarrays were used to detect differentially expressed genes. Many regulated genes could be related to regulation of apoptosis, fewer to proliferation, and the largest group of regulated genes was transcriptional factors several of which may be involved in regulation of growth. Control studies using quantitative real-time RT-PCR showed a high degree of consistency of the microarray results. In conclusion, octreotide exerts a negative effect on growth of the oxyntic mucosa, and extensive gene expression changes relevant to growth regulation can be detected.
Publication Title
Octreotide induces apoptosis in the oxyntic mucosa.
Sample Metadata Fields
No sample metadata fields
View Samples- Populus x canadensis, Populus maximowiczii x populus nigra
- 24 Downloadable Samples
- Affymetrix Poplar Genome Array (poplar)
Description
As exposure to episodic drought can impinge significantly on forest health and the establishment of productive tree plantations, there is great interest in understanding the mechanisms of drought response in trees. The ecologically dominant and economically important genus Populus, with its sequenced genome, provides an ideal opportunity to examine transcriptome level changes in trees in response to a drought stimulus. The transcriptome level drought response of two commercially important hybrid Populus clones (P. deltoides P. nigra, DN34, and P. nigra P. maximowiczii, NM6) was characterized over a diurnal period using a 4 2 2 completely randomized factorial ANOVA experimental design (four time points, two genotypes, and two treatment conditions) using Affymetrix Poplar GeneChip microarrays. Notably, the specific genes that exhibited changes in transcript abundance in response to drought differed between the genotypes and/or the time of day that they exhibited their greatest differences. This study emphasizes the fact that it is not possible to draw simple, generalized conclusions about the drought response of the genus Populus on the basis of one species, nor on the basis of results collected at a single time point. The data derived from our studies provide insights into the variety of genetic mechanisms underpinning the Populus drought response, and provide candidates for future experiments aimed at understanding this response across this economically and ecologically important genus.
Publication Title
Genotype and time of day shape the Populus drought response.
Sample Metadata Fields
Age, Specimen part, Treatment
View Samples- Rattus norvegicus
- 26 Downloadable Samples
- Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
Gene expression from primary neuronal, astrocytic, oligodendrocytic and microglial cultures, as well as from RNA mixtures thereof.
Publication Title
Population-specific expression analysis (PSEA) reveals molecular changes in diseased brain.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 8 Downloadable Samples
- Affymetrix Mouse Gene 1.1 ST Array (mogene11st)
Description
anti-CD4, CD8 and CD40L treated versus control murine CD4+ T cells from micegrafted with hESC derived xenografts.
Publication Title
Tolerance induction to human stem cell transplants with extension to their differentiated progeny.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 5 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
In an effort to identify genes whose expression is regulated by activated PI3K signaling, we performed microarray analysis and subsequent qRT-PCR on an isogenic set of PTEN gene-targeted human cancer cells. Numerous p53 effectors were upregulated following PTEN deletion, including p21, GDF15, PIG3, NOXA, and PLK2. Stable depletion of p53 led to reversion of the gene expression program. Western blots revealed that p53 was stabilized in HCT116 PTEN-/- cells via an Akt1-dependent and p14ARF-independent mechanism. Stable depletion of PTEN in untransformed human fibroblasts and epithelial cells also led to upregulation of p53 and senescent-like growth arrest. Simultaneous depletion of p53 rescued this phenotype, enabling PTEN-depleted cells to continue proliferating. Next, we tested whether oncogenic PIK3CA, like inactivated PTEN, could activate p53. Retroviral expression of oncogenic human PIK3CA in MCF10A cells led to activation of p53 and upregulation of p53-regulated genes. Stable depletion of p53 reversed these PIK3CA-induced expression changes and synergized with oncogenic PIK3CA in inducing anchorage-independent growth. Finally, targeted deletion of an endogenous allele of oncogenic but not wild-type PIK3CA in a human cancer cell line led to a reduction in p53 levels and a decrease in the expression of p53-regulated genes. These studies demonstrate that activation of PI3K signaling by mutations in PTEN or PIK3CA can lead to activation of p53-mediated growth suppression in human cells, indicating that p53 can function as a brake on PIP3-induced mitogenesis during human cancer pathogenesis.
Publication Title
Activation of p53-dependent growth suppression in human cells by mutations in PTEN or PIK3CA.
Sample Metadata Fields
No sample metadata fields
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