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E-MEXP-152
Drosophila melanogaster
7 Downloadable Samples
Affymetrix Drosophila Genome Array (drosgenome1)
Description
We used oligonucleotide microarrays to address the specificities of transcriptional responses of adult Drosophila to different stresses induced by paraquat and H2O2, two oxidative stressors, and by tunicamycin which induces an endoplasmic reticulum (ER) stress. Flies were tested 24 hours after exposure to continuous stresses induced by ingestion of paraquat, H2O2 or tunicamycin at concentrations leading to similar effects on viability. We used concentrations of 1% H2O2, 5mM paraquat and 12uM of tunicamycin which lead to negligeable mortality at 24 hours. A paraquat concentration of 15mM was also used for comparison with previous studies Both specific and common responses to the three stressors were observed and whole genome functional analysis identified several important classes of stress responsive genes. Within some functional classes, we observed large variabilities of transcriptional changes between isozymes, which may reflect unsuspected functional specificities.
Publication Title
Genome wide analysis of common and specific stress responses in adult drosophila melanogaster.
Sample Metadata Fields
Sex, Age, Compound, Time
View Samples- Homo sapiens
- 23 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
The rapid development in septic patients of features of marked immunosuppression associated with increased risk of nosocomial infections and mortality represents the rational for the initiation of immune targeted treatments in sepsis. However, as there is no clinical sign of immune dysfunctions, the current challenge is to develop biomarkers that will help clinicians identify the patients that would benefit from immunotherapy and monitor its efficacy. Using an in vitro model of endotoxin tolerance (ET), a pivotal feature of sepsis-induced immunosuppression in monocytes, we identified using gene expression profiling by microarray a panel of transcripts associated with the development of ET which expression was restored after immunostimulation with interferon-gamma (IFN-). These results were confirmed by qRT-PCR. Importantly, this short-list of markers was further evaluated in patients. Of these transcripts, six (TNFAIP6, FCN1, CXCL10, GBP1, CXCL5 and PID1) were differentially expressed in septic shock patients blood compared to healthy blood upon ex vivo LPS stimulation and were restored by IFN-. In this study, by combining a microarray approach in an in vitro model and a validation in clinical samples, we identified a panel of six transcripts that could be used for the identification of septic patients eligible for IFNg therapy. The potential value of these markers should now be evaluated in a larger cohort of patients. Upon favorable results, they could serve as stratification tools prior to immunostimulatory treatment and to monitor drug efficacy.
Publication Title
Identification of biomarkers of response to IFNg during endotoxin tolerance: application to septic shock.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 9 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Radiotherapy is widely used to treat human cancer. Patients locally recurring after radiotherapy, however, have increased risk of metastatic progression and poor prognosis. The clinical management of post-radiation recurrences remains an unresolved issue. Tumors growing in pre-irradiated tissues have an increased fraction of hypoxic cells and are more metastatic, a condition known as tumor bed effect. Here we demonstrate that tumor cells growing in a pre-irradiated bed, or selected in vitro though repeated cycles of severe hypoxia, retain an invasive and metastatic capacities when returned to normoxia. HIF activity, while it facilitates metastatic spreading of tumors growing in a pre-irradiated bed, is not essential. Through gene expression profiling and gain and loss of function experiments, we identified the matricellular protein CYR61 and aVb5 integrin, as proteins cooperating to mediate these effects. Inhibition of aVb5 integrin suppressed invasion and metastasis induced by CYR61 and attenuated metastasis of tumors growing within a pre-irradiated field. These results represent a conceptual advance to the understanding of the tumor bed effect and identify CYR61 and aVb5 integrin as proteins that co-operate to mediate metastasis. They also indicate aV integrin inhibition a potential therapeutic approach for preventing metastasis in patients at risk for post-radiation recurrences, which can be promptly tested in the clinic.
Publication Title
CYR61 and alphaVbeta5 integrin cooperate to promote invasion and metastasis of tumors growing in preirradiated stroma.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 15 Downloadable Samples
- Affymetrix Human Exon 1.0 ST Array [probe set (exon) version (huex10st)
Description
Alternative splicing of pre-mRNA generates protein diversity and has been linked to cancer progression and drug response. Exon microarray technology enables genome-wide quantication of expression levels for the majority of exons and facilitates the discovery of alternative splicing events. Analysis of exon array data is more challenging than gene expression data and there is a need for reliable quantication of exons and alternative spliced variants. We introduce a novel, computationally efficient methodology, MEAP, for exon array data preprocessing, analysis and visualization. We compared MEAP with other preprocessing methods, and validation of the results show that MEAP produces reliable quantication of exons and alternative spliced variants. Analysis of data from head and neck squamous cell carcinoma (HNSCC) cell lines revealed several variants associated with 11q13 amplication, which is a predictive marker of metastasis and decreased survival in HNSCC patients. Together these results demonstrate the utility of MEAP in suggesting novel experimentally testable predictions. Thus, in addition to novel methodology to process large-scale exon array data sets, our results provide several HNSCC candidate genes for further studies.
Publication Title
Comprehensive exon array data processing method for quantitative analysis of alternative spliced variants.
Sample Metadata Fields
Cell line
View Samples- Mus musculus
- 30 Downloadable Samples
- Illumina MouseWG-6 v2.0 expression beadchip
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Norrin/Frizzled4 signalling in the preneoplastic niche blocks medulloblastoma initiation.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 18 Downloadable Samples
- Illumina MouseWG-6 v2.0 expression beadchip
Description
Medulloblastoma (MB), a tumor of the cerebellum, is the most common malignant brain tumor in children. One third of all human MB exhibits a gene expression signature of Sonic hedgehog (Shh) signaling. Hedgehog (Hh) pathway inhibitors have shown efficacy in clinical trials for MB, however, tumors develop resistance to these compounds, highlighting the need to identify additional therapeutic targets for treatment. We have identified a role for Norrin signaling in tumor initiation in the Patched (Ptch) mouse model of MB. Norrin is a secreted factor that functions as an atypical Wnt by binding to the Frizzled4 (Fzd4) receptor on endothelial cells to activate canonical beta-catenin-mediated Wnt signaling pathway. In the cerebellum, activation of Norrin/Fzd4 signaling is required for the establishment and maintenance of the blood brain barrier (BBB). We have identified a role for Norrin signaling in the stroma as a potent tumor inhibitory signal. Inactivation of Norrin in Ptch+/- mice significantly shortens latency and increases MB incidence. This phenotype is associated with an increased frequency of pre-tumor lesions and their conversion to malignancy. In this context, loss of Norrin signalling in endothelial cells is associated with an accelerated transition to a pro-tumor stroma characterized by vascular permeability, inflammation and angiogenic remodelling. Accordingly, loss of Ndp significantly alters the stromal gene expression signature of established Ptch MB.
Publication Title
Norrin/Frizzled4 signalling in the preneoplastic niche blocks medulloblastoma initiation.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 12 Downloadable Samples
- Illumina MouseWG-6 v2.0 expression beadchip
Description
Medulloblastoma (MB), a tumor of the cerebellum, is the most common malignant brain tumor in children. One third of all human MB exhibits a gene expression signature of Sonic hedgehog (Shh) signaling. Hedgehog (Hh) pathway inhibitors have shown efficacy in clinical trials for MB, however, tumors develop resistance to these compounds, highlighting the need to identify additional therapeutic targets for treatment. We have identified a role for Norrin signaling in tumor initiation in the Patched (Ptch) mouse model of MB. Norrin is a secreted factor that functions as an atypical Wnt by binding to the Frizzled4 (Fzd4) receptor on endothelial cells to activate canonical beta-catenin-mediated Wnt signaling pathway. In the cerebellum, activation of Norrin/Fzd4 signaling is required for the establishment and maintenance of the blood brain barrier (BBB). We have identified a role for Norrin signaling in the stroma as a potent tumor inhibitory signal. Inactivation of Norrin in Ptch+/- mice significantly shortens latency and increases MB incidence. This phenotype is associated with an increased frequency of pre-tumor lesions and their conversion to malignancy. In this context, loss of Norrin signalling in endothelial cells is associated with an accelerated transition to a pro-tumor stroma characterized by vascular permeability, inflammation and angiogenic remodelling. Accordingly, loss of Ndp significantly alters the stromal gene expression signature of established Ptch MB.
Publication Title
Norrin/Frizzled4 signalling in the preneoplastic niche blocks medulloblastoma initiation.
Sample Metadata Fields
Specimen part
View Samples- Arabidopsis thaliana
- 8 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
LEAFY target genes reveal floral regulatory logic, cis motifs, and a link to biotic stimulus response.
Sample Metadata Fields
Specimen part
View Samples- Arabidopsis thaliana
- 8 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
The transition from vegetative growth to flower formation is critical for the survival of flowering plants. The plant-specific transcription factor LEAFY (LFY) has central, evolutionarily conserved roles in this process, both in the formation of the first flower and later in floral patterning. We performed genome-wide binding and expression studies to elucidate the molecular mechanisms by which LFY executes these roles. Our study reveals that LFY directs an intricate regulatory network in control of floral homeotic gene expression and, unexpectedly, controls the expression of genes regulating the response to external stimuli in Arabidopsis. We further show that LFY dampens responses to a bacterial MAMP (microbe-associated molecular pattern) and to pathogen challenge. Our findings suggest a molecular mechanism for the coordination of reproductive stage development and disease response programs in plants. Regulation of these distinct survival programs by a single transcription factor may ensure optimal allocation of plant resources for reproductive fitness.
Publication Title
LEAFY target genes reveal floral regulatory logic, cis motifs, and a link to biotic stimulus response.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 5 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Type I interferon (IFN) is a family of 15 cytokines (in human 13, 1,1) which exert several cellular functions through the binding to a common receptor. Despite the initial activation of the same Jak/Stat signalling pathway, the cellular response may be different depending on the type I IFN subtype. We investigated the activity of different type I IFN subtypes - IFN1, 2, 8, 21, and - on the differentiation of DC. Transcriptome analyses identified two distinct groups, the IFN/-DC and the IFN-DC. 78 genes, 7 chemokines and expression levels of cell surface markers characteristic of DC distinguished IFN-DC and IFN-DC. These differences are unlikely to impact the efficacy of T cell functional response since IFN2-DC and IFN-DC were equipotent in inducing the proliferation and the polarization of allogenic nave CD4 T cells into Th1 cells and in stimulating autologous memory CD4 or CD8 T cells. In contrast, IFN2-DC were found to be more efficient than IFN-DC in the phagocytic uptake of dead cells.
Publication Title
Differential activity of type I interferon subtypes for dendritic cell differentiation.
Sample Metadata Fields
No sample metadata fields
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