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GSE24810
Homo sapiens
47 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Cellular senescence is a program of irreversible cell cycle arrest that normal cells undergo in response to progressive shortening of telomeres, changes in telomeric structure, oncogene activation or oxidative stress. The underlying signalling pathways, potentially of major clinicopathological relevance, are unknown. A major stumbling block to studying senescence has been the absence of suitable model systems because of the asynchrony of this process in heterogeneous cell populations. To simplify this process many investigators study oncogene-induced senescence due to expression of activated oncogenes where senescence occurs prematurely without telomere attrition and can be induced acutely in a variety of cell types. We have taken a different approach by making use of the finding that reconstitution of telomerase activity by introduction of the catalytic subunit of human telomerase alone is incapable of immortalising all human somatic cells, but inactivation of the p16-pRB and p53-p21 pathways are required in addition. The ability of SV40 large T antigen to inactivate the p16-pRB and p53-p21 pathways has enabled us to use a thermolabile mutant of LT antigen, in conjunction with hTERT, to develop conditionally immortalised human (HMF3A) fibroblasts that are immortal but undergo an irreversible growth arrest when the thermolabile LT antigen is inactivated leading to activation of pRB and p53. When these cells cease dividing, senescence-associated- b-galactosidase activity is induced and the growth-arrested cells have morphological features and express genes in common with senescent cells. Since these cells growth arrest in a synchronous manner they are an excellent starting point for dissecting the pathways that underlie cellular senescence and act downstream of p16-pRB and p53-p21 pathways. We have combined genome-wide expression profiling with genetic complementation to undertake identification of genes that are differentially expressed when these conditionally immortalised human fibroblasts undergo senescence upon activation of the p16-pRB and p53-p21 tumour suppressor pathways.
Publication Title
Activation of nuclear factor-kappa B signalling promotes cellular senescence.
Sample Metadata Fields
Cell line, Treatment
View Samples- Mus musculus
- 41 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Prions consist of aggregates of abnormal conformers of cellular prion protein (PrPC). They propagate by recruiting host-encoded PrPC although the critical interacting proteins and the reasons for the differences in susceptibility of distinct cell lines and populations are unknown. We derived a lineage of cell lines with markedly differing susceptibilities, unexplained by PrPC expression differences, to identify such factors. We examined the transcriptomes of prion-resistant revertants, isolated from highly susceptible cells, and identified a gene expression signature associated with susceptibility. Several of these genes encode proteins with a role in extracellular matrix (ECM) remodelling, a compartment in which disease-related PrP deposits. Loss-of-function of nine of these genes significantly increased susceptibility. Remarkably, inhibition of fibronectin 1 binding to integrin 8 by RGD peptide inhibited metalloproteinases (MMP)-2/9 whilst increasing prion propagation rates. This indicates that prion replication may be controlled by MMPs at the ECM in an integrin-dependent manner.
Publication Title
Identification of a gene regulatory network associated with prion replication.
Sample Metadata Fields
Treatment
View Samples- Mus musculus
- 25 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Prion diseases are fatal neurodegenerative disorders that include bovine spongiform encephalopathy (BSE) and scrapie in animals and Creutzfeldt-Jakob disease (CJD) in humans. They are characterized by long incubation periods, variation in which is determined by many factors including genetic background. In some cases it is possible that incubation time may be directly correlated to the level of gene expression. In order to test this hypothesis we combined incubation time data from five different inbred lines of mice with quantitative gene expression profiling in normal brains and identified five genes with expression levels that correlate with incubation time. One of these genes, Hspa13 (Stch), is a member of the Hsp70 family of ATPase heat shock proteins which have been previously implicated in prion propagation. To test whether Hspa13 plays a causal role in determining the incubation period we tested two over-expressing mouse models. The Tc1 human chromosome 21 (Hsa21) transchromosomic mouse model of Down syndrome is trisomic for many Hsa21 genes including Hspa13 and following Chandler/RML prion inoculation shows a 4% reduction in incubation time. Furthermore, a transgenic model with eight fold over-expression of mouse Hspa13 exhibited highly significant reductions in incubation time of 16%, 15% and 7% following infection with Chandler/RML, ME7 and MRC2 prion strains respectively. These data further implicate Hsp70-like molecular chaperones in protein misfolding disorders such as prion disease.
Publication Title
Overexpression of the Hspa13 (Stch) gene reduces prion disease incubation time in mice.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 12 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Geminin is a small nucleoprotein that neuralizes ectoderm in the Xenopus embryo. Geminin promotes neural fate acquisition of mouse embryonic stem cells: Geminin knockdown during neural fate acquisition decreased expression of neural precursor cell markers (Pax6, Sox1), while increasing expression of Pitx2, Lefty1 and Cited2, genes involved in formation of the mouse node. Here we differentiated mouse embryonic stem cells into embryoid bodies to study Geminin's ability to repress primitive streak mesendoderm fate acquisition. We used microarrays to define the sets of genes that are regulated by Geminin during cell fate acquisition in embryoid bodies, using Dox-inducible Geminin knockdown or overexpression mouse embryonic stem cell lines.
Publication Title
Geminin restrains mesendodermal fate acquisition of embryonic stem cells and is associated with antagonism of Wnt signaling and enhanced polycomb-mediated repression.
Sample Metadata Fields
Specimen part
View Samples- Xenopus laevis
- 12 Downloadable Samples
- Affymetrix Xenopus laevis Genome Array (xenopuslaevis)
Description
Geminin cooperates with Polycomb to restrain multi-lineage commitment in the early embryo: Transient maintenance of a pluripotent embryonic cell population followed by the onset of multi-lineage commitment is a fundamental aspect of development. However, molecular regulation of this transition is not well characterized in vivo. Here we demonstrate that the nuclear protein Geminin is required to restrain commitment and spatially restrict mesoderm, endoderm, and non-neural ectoderm to their proper locations in the Xenopus embryo. We used microarray analyses to demonstrate that Geminin overexpression represses many genes associated with cell commitment and differentiation, while elevating expression levels of genes that maintain pluripotent early and immature neurectodermal cell states. We characterized Geminins relationship to cell signaling and found that Geminin broadly represses Activin-, FGF-, and BMP-mediated cell commitment. Conversely, Geminin knockdown enhances commitment responses to growth factor signaling and causes ectopic mesodermal, endodermal, and epidermal fate commitment in the embryo. We also characterized Geminins functional relationship with transcription factors that had similar activities and found that Geminin represses commitment independent of Oct4 ortholog (Oct25/60) activities, but depends upon intact Polycomb repressor function. Consistent with this, chromatin immunoprecipitation assays directed at mesodermal genes demonstrate that Geminin promotes Polycomb binding and Polycomb-mediated repressive histone modifications, while inhibiting modifications associated with gene activation. This work defines Geminin as an essential regulator of the embryonic transition from pluripotency through early multi-lineage commitment, and demonstrates that functional cooperativity between Geminin and Polycomb contributes to this process.
Publication Title
Geminin cooperates with Polycomb to restrain multi-lineage commitment in the early embryo.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 51 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Background Published multi-gene classifiers suggested outcome prediction for patients with stage UICC II colon cancer based on different gene expression signatures. However, there is currently no translation of these classifiers for application in routine diagnostic. Therefore, we aimed at validating own and published gene expression signatures employing methods which enable RNA and protein detection in routine diagnostic specimens. Results Immunohistochemistry was applied to 68 stage UICC II colon cancers to determine the protein expression of five selected previously published classifier genes (CDH17, LAT, CA2, EMR3, and TNFRSF11A). Correlation of protein expression data with clinical outcome within a 5-year post-surgery course failed to separate patients with a disease-free follow-up [Group DF] and relapse [Group R]). In addition, RNA from macrodissected tumor samples from 53 of these 68 patients was profiled on Affymetrix GeneChips (HG-U133 Plus 2.0). Prognostic signatures were generated by Nearest Shrunken Centroids with cross-validation. Although gene expression profiling allowed the identification of differentially expressed genes between the groups DF and R, a stable classification and prognosis signature was not discernable in our data. Furthermore, the application of previously published gene signatures consisting of 22 and 19 genes, respectively, to our gene expression data set using global tests and leave-one-out cross-validation was unable to predict clinical outcome (prediction rate 75.5% and 64.2%; n.s.). T-stage was the only independent prognostic factor for relapse in multivariate analysis with established clinical and pathological parameters including microsatellite status. Conclusions Our protein and gene expression analyses currently do not support application of molecular classifiers for prediction of clinical outcome in routine diagnostic as a basis for patient-orientated therapy in stage UICC II colon cancer. Further studies are needed to develop prognosis signatures applicable in patient care.
Publication Title
Molecular profiles and clinical outcome of stage UICC II colon cancer patients.
Sample Metadata Fields
Sex
View Samples- Homo sapiens
- 19 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Cutaneous T-cell lymphomas form a heterogeneous group of non-Hodgkin lymphomas characterized by only poor prognosis in advanced stage. Despite significant progress made in the identification of novel genes and pathways involved in the pathogenesis of cutaneous lymphoma, the therapeutic value of these findings has still to be proven. Here, we demonstrate by gene expression arrays that aurora kinase A is one of highly overexpressed genes of the serine/threonine kinase in CTCL. The finding was confirmed by qualitative RT-PCR, Western blotting and immunohistochemistry in CTCL cell lines and primary patient samples. Moreover, treatment with a specific aurora kinase A inhibitor blocks cell proliferation by inducing cell cycle arrest in G2 phase as well as apoptosis in CTCL cell lines. These new data provide a promising rationale for using aurora kinase A inhibition as a therapeutic modality of CTCL.
Publication Title
Aurora Kinase A Is Upregulated in Cutaneous T-Cell Lymphoma and Represents a Potential Therapeutic Target.
Sample Metadata Fields
Specimen part, Subject
View Samples- Homo sapiens
- 57 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
Background. Rheumatoid arthritis (RA) is a chronic inflammatory and destructive joint disease, characterized by overexpression of pro-inflammatory/-destructive genes and other activating genes (e.g., proto-oncogenes) in the synovial membrane (SM). The gene expression in disease is often characterized by significant inter-individual variances via specific synchronization/ desynchronization of gene expression. To elucidate the contribution of the variance to the pathogenesis of disease, expression variances were tested in SM samples of RA patients, osteoarthritis (OA) patients, and normal controls (NC).
Publication Title
Identification of intra-group, inter-individual, and gene-specific variances in mRNA expression profiles in the rheumatoid arthritis synovial membrane.
Sample Metadata Fields
Sex, Age, Disease
View Samples- Homo sapiens
- 8 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Genome-wide gene expression analysis of Reh cells following transfection with constitutively active IRF5-4D, constitutively active IKK(EE), or both in combination.
Publication Title
Mapping of transcription factor motifs in active chromatin identifies IRF5 as key regulator in classical Hodgkin lymphoma.
Sample Metadata Fields
Cell line
View Samples- Mus musculus
- 6 Downloadable Samples
- Illumina MouseWG-6 v2.0 R2 expression beadchip
Description
Genome-wide gene expression analysis of murine splenic B-cells following retroviral transduction with a constitutively active IRF5 (IRF5-4D)
Publication Title
Mapping of transcription factor motifs in active chromatin identifies IRF5 as key regulator in classical Hodgkin lymphoma.
Sample Metadata Fields
Specimen part
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