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GSE7473
Homo sapiens
9 Downloadable Samples
Affymetrix Human Genome U133A Array (hgu133a)
Description
Biallelic inactivating mutations of the transcription factor 1 gene (TCF1), encoding hepatocyte nuclear factor 1a (HNF1a), were identified in 50% of hepatocellular adenomas (HCA) phenotypically characterized by a striking steatosis. To understand the molecular basis of this aberrant lipid storage, we performed a microarray transcriptome analysis validated by quantitative RT-PCR, western-blotting and lipid profiling. In mutated HCA, we showed a repression of gluconeogenesis coordinated with an activation of glycolysis, citrate shuttle and fatty acid synthesis predicting elevated rates of lipogenesis. Moreover, the strong dowregulation of L-FABP suggests that impaired fatty acid trafficking may also contribute to the fatty phenotype. In addition, transcriptional profile analysis of the observed deregulated genes in non-HNF1a-mutated HCA as well as in non-tumor livers allowed us to define a specific signature of the HNF1a-mutated HCA. In theses tumors, lipid composition was dramatically modified according to the transcriptional deregulations identified in the fatty acid synthetic pathway. Surprisingly, lipogenesis activation did not operate through SREBP-1 and ChREBP that were repressed. We conclude that steatosis in HNF1a-mutated HCA results mainly from an aberrant promotion of lipogenesis that is linked to HNF1a inactivation and that is independent of both SREBP-1 and ChREBP activation. Finally, our findings have potential clinical implications since lipogenesis can be efficiently inhibited by targeted therapies.
Publication Title
HNF1alpha inactivation promotes lipogenesis in human hepatocellular adenoma independently of SREBP-1 and carbohydrate-response element-binding protein (ChREBP) activation.
Sample Metadata Fields
Sex, Specimen part, Disease
View Samples- Homo sapiens
- 8 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
Focal nodular hyperplasias (FNHs) are benign liver lesions considered to be a hyperplastic response to increased blood flow in otherwise normal liver. In contrast, FNH-like nodules occur in cirrhotic liver but share similar histopathological features. To better understand the pathophysiology of FNH, we performed a transcriptomic analysis. Methods: Affymetrix and cDNA microarrays were used to compare gene expression in eight FNHs with that in tissue from six normal livers. Selected genes were validated with quantitative RT-PCR in 70 benign liver tumors including adenomas and cirrhotic and FNH-like lesions. Results: Among the deregulated genes in FNHs, 19 were physiologically zonated in the normal liver lobule. All six periveinous genes were up-regulated in FNH, whereas 13 genes normally expressed in the periportal area were down-regulated. Immunohistochemistry revealed that glutamine synthetase was markedly overexpressed, forming anastomosed areas usually centered on visible veins. -catenin mRNA was slightly but significantly overexpressed, as were several known -catenin target genes. Moreover, activated hypophosphorylated -catenin protein accumulated in FNH in the absence of activating mutations. These results suggest zonated activation of the -catenin pathway specifically in FNH, whereas the other benign hepatocellular tumors, including FNH-like lesions, demonstrated an entirely different pattern of -catenin expression. Conclusions: In FNH, increased expression of the -catenin pathway was restricted to enlarged periveinous areas, which may explain the slight polyclonal over-proliferation of hepatocytes at the origin of the lesion. FNH-like nodules may have a different pathogenetic origin.
Publication Title
The beta-catenin pathway is activated in focal nodular hyperplasia but not in cirrhotic FNH-like nodules.
Sample Metadata Fields
Sex, Specimen part, Disease
View Samples- Homo sapiens
- 16 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
Inflammatory hepatocellular adenomas (IHCA) are benign liver tumours defined by the presence of inflammatory infiltrates and by the elevated expression of inflammatory proteins in tumour hepatocytes1,2. Here we show a striking activation of the IL6 signalling pathway in this tumour type, and sequencing candidate genes pinpointed this response to somatic gain-of-function mutations in the IL6ST gene that encodes the signalling co-receptor gp130. Indeed, ~70% of IHCA harbour small in-frame deletions that target the binding site of gp130 for IL6, and expression of the most frequent gp130 mutant, Delta-STVY190, in hepatocellular cells activates STAT3 in absence of ligand. Further, analysis of hepatocellular carcinomas revealed rare gp130 alterations always accompanied by -catenin-activating mutations, suggesting a cooperative effect of these signalling pathways in the malignant conversion of hepatocytes. The recurrent gain-of-function gp130 mutations in these human hepatocellular adenomas explains their inflammatory phenotype, and suggest that similar alterations may occur in other inflammatory epithelial tumours with STAT3 activation.
Publication Title
Frequent in-frame somatic deletions activate gp130 in inflammatory hepatocellular tumours.
Sample Metadata Fields
Sex, Specimen part, Disease
View Samples- Homo sapiens
- 25 Downloadable Samples
- Affymetrix Human Exon 1.0 ST Array [transcript (gene) version (huex10st)
Description
This work focuses on understanding the molecular basis of the immune dysfunctions in Idiopathic CD4+ T cells lymphocytopenia (ICL). ICL is a rare haematological disorder of unknown origin, characterized by a profound and persistent CD4+ T-cell defect, which predisposes to life threatening opportunistic infections very similar to those seen in AIDS. To analyse more in depth the functional pathways involved in ICL pathogenesis, we conducted gene expression profiling of CD4+ T-cells isolated from blood samples from ICL, sarcoidosis and healthy individuals. Our analyses have revealed specific CD4+ T-cells gene expression signatures in ICL associated with defective TCR activation threshold, expansion of the Treg-cell compartment and interestingly with accelerated immune aging.
Publication Title
DUSP4-mediated accelerated T-cell senescence in idiopathic CD4 lymphopenia.
Sample Metadata Fields
Sex
View Samples- Homo sapiens
- 90 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Hepatocellular carcinoma (HCC) is ranked second in cancer-associated deaths worldwide. Most cases of HCC are secondary to either a viral hepatitis infection (hepatitis B or C) or cirrhosis (alcoholism being the most common cause of hepatic cirrhosis). It is a complex and heterogeneous tumor due to activation of multiple cellular pathways and molecular alterations.
Publication Title
Exome sequencing of hepatocellular carcinomas identifies new mutational signatures and potential therapeutic targets.
Sample Metadata Fields
Sex, Age, Specimen part, Disease, Disease stage
View Samples- Arabidopsis thaliana
- 55 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Seedlings of 35 different Arabidopsis thaliana ecotypes were compared. Triplicates were performed of 10 ecotpyes, single arrays of 25 ecotypes.
Publication Title
Diversity of flowering responses in wild Arabidopsis thaliana strains.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 26 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Multiple Sclerosis (MS) is an immune-mediated chronic inflammatory disease affecting the central nervous system. The cause of MS is not known and the mechanism of IFN-beta, a disease-modifying treatment (DMT) approved for MS, is not well-understood. Oligonucleotide microarrays were used to study gene expression in plasmacytoid denditic cells (pDCs) which are antigen-presenting cells implicated in MS pathogenesis.
Publication Title
Multiple sclerosis-linked and interferon-beta-regulated gene expression in plasmacytoid dendritic cells.
Sample Metadata Fields
Sex, Age, Specimen part, Disease, Disease stage, Subject
View Samples- Homo sapiens
- 16 Downloadable Samples
- Affymetrix Human Transcriptome Array 2.0 (hta20)
Description
Transcripts (mRNA) during amino acid limitation after MEK was inhibited were analyzed.
Publication Title
A mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK)-dependent transcriptional program controls activation of the early growth response 1 (EGR1) gene during amino acid limitation.
Sample Metadata Fields
Cell line, Treatment
View Samples- Pseudomonas aeruginosa
- 12 Downloadable Samples
- Affymetrix Pseudomonas aeruginosa Array (paeg1a)
Description
The transcriptional regulator AmpR controls expression of the AmpC -lactamase in P. aeruginosa and other bacteria. Studies have demonstrated that in addition to regulating ampC expression, AmpR also regulates the expression of the sigma factor AlgT/U and the production of some quorum-sensing regulated virulence factors. In order to understand the ampR regulon, we compared the expression profiles of PAO1 and its isogenic ampR mutant, PAOampR in the presence and absence of sub-MIC -lactam stress. The analysis demonstrates that the ampR regulon is much more extensive than previously thought, with the deletion of ampR affecting the expression of over 300 genes. Expression of an additional 207 genes are affected by AmpR when the cells are exposed to sub-MIC -lactam stress, indicating that the ampR regulon in P. aeruginosa is much more extensive than previously thought.
Publication Title
The regulatory repertoire of Pseudomonas aeruginosa AmpC ß-lactamase regulator AmpR includes virulence genes.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 10 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
We used microarrays to detail gene expression changes in Hs 294T human melanoma cells after treatment with elesclomol alone, or in combination with paclitaxel, to aide in identifing the mechnism of action of elesclomol.
Publication Title
Elesclomol induces cancer cell apoptosis through oxidative stress.
Sample Metadata Fields
No sample metadata fields
View Samples