This SuperSeries is composed of the SubSeries listed below.
Integrated approaches to miRNAs target definition: time-series analysis in an osteosarcoma differentiative model.
Specimen part, Cell line, Time
View SamplesWe explored the transcriptional modification induced by CD99 transfection in the osteosarcoma cell lines SaOS-2 after 0, 7 and 14 days in differentiation medium.
Integrated approaches to miRNAs target definition: time-series analysis in an osteosarcoma differentiative model.
Specimen part, Cell line, Time
View SamplesHepatitis C virus (HCV) infection is a major cause of chronic liver disease worldwide. The current standard therapy for chronic hepatitis C (CHC) consists of a combination of pegylated IFN alpha (pegIFN-alpha) and ribavirin. It achieves a sustained viral clearance in only 5060% of patients. To learn more about molecular mechanisms underlying treatment failure, we investigated IFN-induced signaling in paired liver biopsies collected from CHC patients before and after administration of pegIFN-alpha. In patients with a rapid virological response to treatment, pegIFN-alpha induced a strong up-regulation of IFN-stimulated genes (ISGs). As shown previously, nonresponders had high expression levels of ISGs before therapy. Analysis of posttreatment biopsies of these patients revealed that pegIFN-alpha did not induce expression of ISGs above the pretreatment levels. In accordance with ISG expression data, phosphorylation, DNA binding, and nuclear localization of STAT1 indicated that the IFN signaling pathway in nonresponsive patients is preactivated and refractory to further stimulation. Some features characteristic of nonresponders were more accentuated in patients infected with HCV genotypes 1 and 4 compared with genotypes 2 and 3, providing a possible explanation for the poor response of the former group to therapy. Taken together with previous findings, our data support the concept that activation of the endogenous IFN system in CHC not only is ineffective in clearing the infection but also may impede the response to therapy, most likely by inducing a refractory state of the IFN signaling pathway.
Interferon signaling and treatment outcome in chronic hepatitis C.
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View SamplesThis work is part of the paper: Generation of a murine hepatic angiosarcoma cell line and reproducible mouse tumor model, Rothweiler S et al, Laboratory Investigation, 2014
Generation of a murine hepatic angiosarcoma cell line and reproducible mouse tumor model.
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View SamplesHepatocellular carcinoma (HCC) is a heterogeneous disease, and despite considerable research efforts, no molecular classification of HCC has been introduced in clinical practice. The existing molecular classification systems were established using resected tumors, which introduces a selection bias towards patients without liver cirrhosis and with early stage HCCs. So far, these classification systems have not been validated in liver biopsy specimens from tumors diagnosed at intermediate and late stages. We generated and analyzed expression profiles from 60 HCC biopsies from an unselected patient population with all tumor stages. Unbiased clustering identified 3 HCC classes. Class membership correlated with survival, tumor size, and with Edmondson and BCLC stage. Most biopsy specimens could be assigned to the classes of published classification systems, demonstrating that gene expression profiles obtained from patients with early stage disease are preserved in all stages of HCC. When a reference set of healthy liver samples was integrated in the analysis, we observed that the differentially regulated genes up- or down-regulated in a given class relative to other classes were actually dysregulated in the same direction in all HCCs, with quantitative rather than qualitative differences between the molecular subclasses. With the exception of a subset of samples with a definitive -catenin gene signature, biological pathway analysis could not identify class specific pathways reflecting the activation of distinct oncogenic programs. Our results suggest that gene expression profiling of HCC biopsies has limited potential to direct therapies that target specific driver pathways, but can identify subgroups of patients with different prognosis.
Gene expression analysis of biopsy samples reveals critical limitations of transcriptome-based molecular classifications of hepatocellular carcinoma.
Specimen part, Disease, Disease stage
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Interferon-γ-stimulated genes, but not USP18, are expressed in livers of patients with acute hepatitis C.
Specimen part, Disease, Disease stage, Treatment, Subject, Time
View SamplesApproximately 50% of patients with chronic hepatitis C (CHC) have a sustained virologic response (SVR) to treatment with pegylated interferon (pegINF)- and ribavirin. Non-response to treatment is associated with constitutively increased expression of IFN-stimulated genes (ISGs) in the liver. Treatment of patients with acute hepatitis C (AHC) is more effective, with SVR rates >90%. We investigated mechanisms of the different responses of patients with CHC and AHC to pegIFN- therapy. We analyzed IFN signaling and ISG expression in liver samples from patients with acute hepatitis C (AHC), patients with chronic hepatitis (CHC), and individuals without hepatitis C (controls) using microarray, immunohistochemical, and protein analyses. Findings were compared with those from primary human hepatocytes stimulated with IFN- or IFN-, as reference sets. Expression levels of 100s of genes, primarily those regulated by IFN-, were altered in liver samples from patients with AHC compared with controls. Expression of IFN-stimulated genes was induced in liver samples from patients with AHC, whereas expression of IFN-stimulated genes was induced in samples from patients with CHC. In an expression analysis of negative regulators of IFN- signaling, we did not observe differences in expression of SOCS1 or SOCS3 between liver samples from patients with AHC and those with CHC. However, USP18 (another negative regulator of IFN- signaling), was upregulated in liver samples of patients with CHC that did not respond to therapy, but not in AHC. In conclusion, differences in expression of ISGs might account for the greater response of patients with AHC, compared to those with CHC, to treatment with pegINF- and ribavirin. Specifically, USP18 is upregulated in liver samples of patients with CHC that do not respond to therapy, but not in patients with AHC.
Interferon-γ-stimulated genes, but not USP18, are expressed in livers of patients with acute hepatitis C.
Specimen part, Treatment, Subject, Time
View SamplesApproximately 50% of patients with chronic hepatitis C (CHC) have a sustained virologic response (SVR) to treatment with pegylated interferon (pegINF)- and ribavirin. Non-response to treatment is associated with constitutively increased expression of IFN-stimulated genes (ISGs) in the liver. Treatment of patients with acute hepatitis C (AHC) is more effective, with SVR rates >90%. We investigated mechanisms of the different responses of patients with CHC and AHC to pegIFN- therapy. We analyzed IFN signaling and ISG expression in liver samples from patients with acute hepatitis C (AHC), patients with chronic hepatitis (CHC), and individuals without hepatitis C (controls) using microarray, immunohistochemical, and protein analyses. Findings were compared with those from primary human hepatocytes stimulated with IFN- or IFN-, as reference sets. Expression levels of 100s of genes, primarily those regulated by IFN-, were altered in liver samples from patients with AHC compared with controls. Expression of IFN-stimulated genes was induced in liver samples from patients with AHC, whereas expression of IFN-stimulated genes was induced in samples from patients with CHC. In an expression analysis of negative regulators of IFN- signaling, we did not observe differences in expression of SOCS1 or SOCS3 between liver samples from patients with AHC and those with CHC. However, USP18 (another negative regulator of IFN- signaling), was upregulated in liver samples of patients with CHC that did not respond to therapy, but not in AHC. In conclusion, differences in expression of ISGs might account for the greater response of patients with AHC, compared to those with CHC, to treatment with pegINF- and ribavirin. Specifically, USP18 is upregulated in liver samples of patients with CHC that do not respond to therapy, but not in patients with AHC.
Interferon-γ-stimulated genes, but not USP18, are expressed in livers of patients with acute hepatitis C.
Specimen part, Disease, Disease stage
View SamplesPegylated interferon- (pegIFN-) has replaced un-modified recombinant IFN- for the treatment of chronic viral hepatitis because of its superior anti-viral efficacy that is generally attributed to improved pharmacokinetic properties. However, the pharmacodynamic effects of pegIFN- in the liver have not been studied. We analyzed pegIFN- induced signaling and gene regulation in paired liver biopsies obtained before treatment and during the first week after injection of pegIFN- in 18 patients. Despite sustained high serum concentrations of pegIFN- over the entire one-week dosing interval, IFN- signaling through the Jak-STAT pathway occurs only during the first day. PegIFN- induces hundreds of genes that can be classified into 4 clusters based on different temporal expression profiles. In all clusters, gene transcription is mainly driven by IFN stimulated gene factor 3 (ISGF3). IFN induced secondary transcription factors do not cause additional waves of gene expression. We could not confirm a role of un-phosphorylated STAT1 in prolonging IFN- induced gene transcription. Collectively, our results reveal that the major effects of pegIFN- in the liver are caused by an early and transient activation of ISGF3. Prolonging the serum half-life of IFN- does not necessarily improve its pharmacodynamic properties.
Pegylated IFN-α regulates hepatic gene expression through transient Jak/STAT activation.
Specimen part, Disease, Disease stage, Treatment, Subject, Time
View SamplesMucosal-associated invariant T (MAIT) cells are abundant in humans and recognize conserved bacterial antigens derived from riboflavin precursors, presented by the non-polymorphic MHC class I-like molecule MR1. Here, we show via transcriptomic analysis that human MAIT cells are remarkably oligoclonal in both blood and liver, display high inter-individual homology, and exhibit a restricted length CDR3ß domain of the TCRVß chain. We extend this analysis to a second sub-population of MAIT cells expressing a semi-invariant TCR conserved between individuals. Overall design: Study of CDR3 regions of TCRalpha and beta sequences
Parallel T-cell cloning and deep sequencing of human MAIT cells reveal stable oligoclonal TCRβ repertoire.
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