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GSE12886
Homo sapiens
5 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
The Wilms tumor 1 gene (WT1) encodes a transcription factor involved in cell growth and development. As we previously reported WT1 expression is hardly detectable in normal hepatic tissue but is induced in liver cirrhosis. Although WT1 has been found to be overexpressed in a number of malignancies, the role of WT1 in hepatocarcinogenesis has not been clarified. We found that WT1 is expressed in several human hepatocellular carcinoma (HCC) cell lines including PLC/PRF/5 and HepG2, and in HCC tumor tissue in 42% of patients. WT1 small interfering RNAs did not affect proliferation rate of HCC cells but abrogated their resistance to anoikis. Transcriptome analysis of PLC/PRF/5 cells after WT1 knockdown demonstrated upregulation of 251 genes and downregulation of 321. Ninety per cent of the former corresponded to metabolic genes mostly those characterizing the mature hepatocyte phenotype. On the contrary, genes that decreased upon WT1 inhibition were mainly related to defense against apoptosis, cell cycle and tumor progression. In agreement with these findings WT1 expression increased the resistance of liver tumor cells to doxorubicin, a compound used to treat HCC. Interestingly, doxorubicin strongly enhanced WT1 expression in both HCC cells and normal human hepatocytes. Among different chemotherapeutics, induction of WT1 transcription was restricted to topoisomerase 2 inhibitors. When WT1 expression was prohibited doxorubicin caused a marked increase in caspase-3 activation. In conclusion, WT1 is expressed in a substantial proportion of HCC contributing to tumor progression and resistance to chemotherapy, suggesting that WT1 may be an important target for HCC treatment.
Publication Title
Wilms' tumor 1 gene expression in hepatocellular carcinoma promotes cell dedifferentiation and resistance to chemotherapy.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 52 Downloadable Samples
Illumina HiScanSQ
Description
Background & Aims. Glycine N-methyltransferase (GNMT) is an essential regulator of the total transmethylation flux in the mammalian liver. Distinct DNA methylation patterns are characteristic of liver development, hepatic de-differentiation and liver disease progression, processes in which the levels of GNMT decrease dramatically by mechanisms still poorly understood. Interestingly, putative binding sites for the microRNA miRNA-873-5p were identified in the 3´UTR of GNMT suggesting a potential role for miRNA-873-5p in GNMT regulation. Results. We have identified that the hepatic expression of miRNA-873-5p was increased in a cohort of cirrhotic and liver cancer patients associated with a down-regulation of GNMT levels. Moreover, during liver development, hepatic de-differentiation and fibrosis, the elevation of miRNA-873-5p coincided with the reduction of GNMT expression, indicating that miRNA-873-5p specifically targets the expression of GNMT. Under these circumstances, inhibition of miRNA-873-5p induced GNMT levels and decreased global CpG methylation and transmethylation flux. Indeed, reestablishment of GNMT expression by miRNA-873-5p inhibition reduced hepatocyte de-differentiation, and abolished completely the mortality produced after bile duct ligation as a result of decreased proinflamatory and profibrogenic markers. miRNA-873-5p knockdown-mediated antifibrotic effect was significantly blunted if its effect on GNMT was blocked. Conclusion. Taken together, our studies highlight the role of miRNA-873-5p as a key regulator of GNMT expression, paving the way for new therapeutical approaches in liver de-differentiation and fibrosis. Overall design: Genome-wide changes in gene Expression in mouse livers from BDL treated or not with anti-miR-873 were generated by RNAseq.
Publication Title
MiR-873-5p acts as an epigenetic regulator in early stages of liver fibrosis and cirrhosis.
Sample Metadata Fields
Age, Cell line, Treatment, Subject
View Samples- Homo sapiens
- 22 Downloadable Samples
- Illumina HumanHT-12 V4.0 expression beadchip
Description
Background and aims: Cholangiocarcinoma (CCA) is a heterogeneous group of malignancies with features of biliary tract differentiation. Incidence is increasing worldwide and these cancers collectively represent the second most common primary liver tumour. CCAs are characterized by genetic and epigenetic alterations that determine their pathogenesis. Hypermethylation of the SOX17 promoter was recently reported in human CCA tumours. SOX17 seems to be a key transcription factor for biliary embryogenesis. Here, we evaluated the role of SOX17 in cholangiocyte differentiation and in cholangiocarcinogenesis. Methods: SOX17 expression and function was evaluated during the differentiation of human induced pluripotent stem cells (iPSC) into cholangiocytes, in the dedifferentiation of normal human cholangiocytes (NHC) and in cholangiocarcinogenesis. Lentiviruses overexpressing or knocking-down SOX17 (Lent-SOX17 and Lent-shRNA-SOX17, respectively) were used. Gene expression arrays were performed. Results: SOX17 expression is highly induced in the later stages of cholangiocyte differentiation from iPSC, and mediates the acquisition of the biliary markers cytokeratin (CK) 7 and 19, as well as fibronectin. In addition, SOX17 becomes progressively downregulated in NHC over serial cell passages in vitro and this event is associated with cellular senescence; however, experimental SOX17 knocking-down in differentiated NHC decreased the expression of both CK7 and 19 without affecting cellular senescence. SOX17 expression is reduced in CCA cells compared to NHC, as well as in human CCA tissue compared to human gallbladder tissue or NHC. In a murine xenograft model, overexpression of SOX17 in CCA cells decreased their tumorigenic capacity related to increased oxidative stress and apoptosis. Interestingly, overexpression of SOX17 in NHC did not affect their survival. Moreover, SOX17 overexpression inhibited the Wnt/-catenin-dependent proliferation in CCA cells and was associated with upregulation of biliary epithelial markers and restoration of the primary cilium length. Both Wnt3a and TGF1 decreased SOX17 expression in NHC in a DNMT1-dependent manner. Inhibition of DNMT1 in CCA cells with siRNAs or pharmacological drugs upregulated SOX17 expression. Conclusion: SOX17 regulates the cholangiocyte phenotype and becomes epigenetically downregulated in CCA. SOX17 acts as a tumour suppressor in CCA, and restoration of its expression may have important therapeutic value.
Publication Title
SOX17 regulates cholangiocyte differentiation and acts as a tumor suppressor in cholangiocarcinoma.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Homo sapiens
- 35 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Obesity is a risk factor for numerous metabolic disorders; however, not all obese individuals are prone to insulin resistance. The central aim of this study was to identify molecular pathways directly related to insulin resistance independent of BMI in obesity.
Publication Title
Body mass index-independent inflammation in omental adipose tissue associated with insulin resistance in morbid obesity.
Sample Metadata Fields
Sex, Specimen part
View Samples- Homo sapiens
- 17 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Obesity is a risk factor for numerous metabolic disorders; however, not all obese individuals are prone to insulin resistance. The central aim of this study was to identify molecular pathways directly related to insulin resistance independent of BMI in obesity.
Publication Title
Body mass index-independent inflammation in omental adipose tissue associated with insulin resistance in morbid obesity.
Sample Metadata Fields
Sex, Specimen part
View Samples- Homo sapiens
- 4 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Protein synthesis belongs to the most energy consuming processes in the cell. Lowering oxygen tension below normal (hypoxia) causes a rapid inhibition of global mRNA translation due to the decreased availability of energy. Interestingly, subsets of mRNAs pursue active translation under such circumstances. In human fibrosarcoma cells (HT1080) exposed to prolonged hypoxia (36 h, 1% oxygen) we observed that transcripts are either increasingly or decreasingly associated with ribosomes localized at the endoplasmic reticulum (ER). In a global setting it turned out that only 31% of transcripts showing elevated total-RNA levels were also increasingly present at the ER in hypoxia. These genes, regulated by its expression as well as its ER-localization, belong to the gene ontologys hypoxia response, glycolysis and HIF-1 transcription factor network supporting the view of active mRNA translation at the ER during hypoxia. Interestingly, a large group of RNAs was found to be unchanged at the expression level, but translocate to the ER in hypoxia. Among these are transcripts encoding translation factors and >180 ncRNAs. In summary, we provide evidence that protein synthesis is favoured at the ER and, thus, partitioning of the transcriptome between cytoplasmic and ER associated ribosomes mediates adaptation of gene expression in hypoxia.
Publication Title
Hypoxia-induced gene expression results from selective mRNA partitioning to the endoplasmic reticulum.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 16 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Aberrant activation of -catenin is a common event in Acute Myeloid Leukemia (AML), and is recognized as an independent predictor of poor prognosis. Although increased -catenin signaling in AML has been associated with AML1-ETO and PML-RAR translocation products, and activating mutations in the FLT3 receptor, it remains unclear which mechanisms activate -catenin in AML more broadly. Here, we describe a novel link between interleukin-3 (IL-3) signaling and the regulation of -catenin in myeloid transformation and AML. Using a murine model of HoxB8 and IL-3 cooperation we show that IL-3 modulates -catenin protein levels, and Cre-induced deletion of -catenin abolishes IL-3 dependent growth and colony formation. In the erythroleukemic cell line TF-1.8, we observed increased -catenin protein levels and nuclear localization in response to IL-3, which correlated with transcriptional induction of -catenin target genes. Furthermore, IL-3 promoted -catenin accumulation in a subset of AML patient samples, and microarray gene expression analysis of these cells revealed induction of WNT/-catenin and TCF4 transcriptional gene signatures in an IL-3 dependent manner. This study is the first to link -catenin activation to IL-3 and suggests that targeting IL-3 signaling may be an effective approach for the inhibition of -catenin activity in some patients with AML.
Publication Title
Interleukin-3-mediated regulation of β-catenin in myeloid transformation and acute myeloid leukemia.
Sample Metadata Fields
Specimen part, Disease, Treatment
View Samples- Homo sapiens
- 3 Downloadable Samples
- Affymetrix Human Gene 2.1 ST Array (hugene21st)
Description
We used microarray analysis to investigate if keratinocytes excert an immuno-inflammatory response towards streptococcal M1 protein.
Publication Title
Vigilant keratinocytes trigger pathogen-associated molecular pattern signaling in response to streptococcal M1 protein.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 8 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Earlier studies had shown that side population cells isolated from established non-small cell lung cancer (NSCLC) cell lines exhibit cancer stem cell properties. Microarray data from side population (SP) and main population (MP) cells isolated from 4 NSCLC lines (A549, H1650, H460, H1975) were used to examine gene expression profiles associated with stemness. Total RNA extracted from SP and MP samples were used to generate cRNA targets, which were hybridized to Human Genome U133 Plus 2.0 probe arrays. Raw data was processed and the mean center expression level for each gene was determined.
Publication Title
A novel five gene signature derived from stem-like side population cells predicts overall and recurrence-free survival in NSCLC.
Sample Metadata Fields
Cell line
View Samples- Arabidopsis thaliana
- 8 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
We used the flu mutant of Arabidopsis and a transgenic line that overexpresses the thylakoid-bound ascorbate peroxidase (tAPX) to address the interactions between different reactive oxygen species (ROS) signaling pathways. The conditional flu mutant of Arabidopsis accumulates excess protochlorophyllide in the dark within chloroplast membranes that upon illumination acts as a photosensitizer and generates singlet oxygen (1O2). Immediately after the release of singlet oxygen rapid changes in nuclear gene expression occur. Distinct sets of genes were activated that were different from those induced by other reactive oxygen species, superoxide or hydrogen peroxide (H2O2), suggesting that different types of active oxygen species activate distinct signaling pathways. It was not known whether the pathways operate separately or interact with each other. We have addressed this problem by modulating noninvasively the level of H2O2 in plastids by means of a transgenic line that overexpresses the thylakoid-bound ascorbate peroxidase (tAPX, line 14/2 PMID: 15165186). In the flu mutant overexpressing tAPX, the expression of most of the nuclear genes that were rapidly activated after the release of 1O2 was significantly higher in flu plants overexpressing tAPX, whereas in wild-type plants, overexpression of tAPX had only a very minor impact on nuclear gene expression. The results suggest that H2O2 antagonizes the 1O2-mediated signaling of stress responses as seen in the flu mutant. This cross-talk between H2O2- and 1O2-dependent signaling pathways might contribute to the overall stability and robustness of wild-type plants exposed to adverse environmental stress conditions.
Publication Title
Cross-talk between singlet oxygen- and hydrogen peroxide-dependent signaling of stress responses in Arabidopsis thaliana.
Sample Metadata Fields
No sample metadata fields
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