Hepatitis C virus (HCV) is widely used to investigate host-virus interactions and cellular responses to infection have been extensively studied in vitro. In human liver, interferon (IFN) stimulated gene expression can mask direct transcriptional responses to virus infection. To better characterize the direct effects of HCV infection in vivo, we analyze the transcriptomes of HCV-infected patients lacking an activated endogenous IFN system. We show that the expression changes observed in these patients predominantly reflect immune cell infiltrates rather than changes in cell-intrinsic metabolic pathways. We also investigate the transcriptomes of patients with endogenous IFN activation, which paradoxically cannot eradicate viral infection. We find that most IFN-stimulated genes (ISGs) are induced by both the endogenous IFN system and by recombinant IFN therapy, but with significantly higher induction levels in the latter. We conclude that the innate host immune response in chronic hepatitis C is too weak to clear the virus. Overall design: In this study, we aimed to disentangle the direct and indirect effects of HCV infection on cellular transcriptional profiles, by performing a detailed characterization of the gene expression changes associated with HCV infection, endogenous IFN system activation and pegIFNa treatment in the human liver. With this objective, we generated and analyzed high-throughput transcriptome sequencing profiles from liver biopsies derived from different categories of HCV-infected and non-infected patients, prior to and during treatment. First, to unveil HCV-induced cell-autonomous effects and to separate them from IFN-induced changes in the transcriptome, we selected liver biopsies from patients with chronic hepatitis C (CHC) without hepatic ISG induction, and compared them with un-infected control biopsies. Second, we examined the transcriptomic changes associated with the endogenous activation of the IFN system. Finally, we analyzed the gene expression changes resulting from pegIFNa/ribavirin treatment, by comparing transcriptome data from liver biopsies obtained before treatment and at different time points during the first week of therapy.
Transcriptional response to hepatitis C virus infection and interferon-alpha treatment in the human liver.
Specimen part, Treatment, Subject
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 SamplesWe analyzed the transcriptome of dormant and after-ripened imbibed seeds of the Arabidopsis accession Cape verde Islands.
Dormant and after-Ripened Arabidopsis thaliana Seeds are Distinguished by Early Transcriptional Differences in the Imbibed State.
Specimen part, Time
View SamplesGenome wide expression profiling was used to identify signifnificantly changed genes in fetal membranes after GBS treatment
Group B streptococcus activates transcriptomic pathways related to premature birth in human extraplacental membranes in vitro.
Specimen part
View SamplesThe identification of recurrent somatic mutations in genes encoding epigenetic enzymes, coupled with biochemical studies demonstrating aberrant recruitment of epigenetic enzymes such as histone deacetylases (HDACs) and histone methyltransferases (HMTs) to promoter regions through association with oncogenic fusion proteins such as PML-RAR and AML1-ETO has provided a strong rationale for the development compounds that target the epigenome for the treatment of cancer. HDAC inhibitors (HDACi) are potent inducers of tumor cell apoptosis but it remains unclear why tumor cells are selectively sensitive to HDACi-induced cell death.
HDAC inhibitors induce tumor-cell-selective pro-apoptotic transcriptional responses.
Specimen part, Time
View SamplesAnalysis of hormone effects on irradiated LBNF1 rat testes, which contain only somatic cells except for a few type A spermatgogonia. Rats were treated for 2 weeks with either sham treatment (group X), hormonal ablation (GnRH antagonist and the androgen receptor antagonist flutamide, group XAF), testosterone supplementation (GnRH antagonist and testosterone, group XAT), and FSH supplementation ((GnRH antagonist, androgen receptor antagonist, and FSH, group XAFF). Results provide insight into identifying genes in the somatic testis cells regulated by testosterone, LH, or FSH.
Changes in gene expression in somatic cells of rat testes resulting from hormonal modulation and radiation-induced germ cell depletion.
Specimen part, Treatment
View SamplesAnalysis of LBNF1 rat testes from controls, containing both somatic and all germ cell types and from irradiated rats in which all cells germ cells except type A spermatgogonia are eliminated. Results provide insight into distinguishing germ and somatic cell genes and identification of somatic cell genes that are upregulated after irradiation.
Changes in gene expression in somatic cells of rat testes resulting from hormonal modulation and radiation-induced germ cell depletion.
Specimen part
View SamplesPharmacological and gene ablation studies have demonstrated a crucial role of the cardiac natriuretic peptides (NP) hormones ANF and BNP in the maintenance of cardiovascular homeostasis. In addition, hypertension and chronic congestive heart failure are clinical entities that may be regarded as states of relative NP deficiency. Hence the study of the function of the endocrine heart is highly relevant.
Transcriptional analysis of the mammalian heart with special reference to its endocrine function.
Sex, Specimen part
View SamplesThe p53 protein is a cell-autonomous tumor suppressor that restricts malignant transformation by triggering cell cycle exit or apoptosis. p53 also promotes cellular senescence, a program that triggers a stable cell cycle arrest and can modify the tissue microenvironment through its effect on cell membrane and secretory proteins. Here we show that specific ablation of p53 in hepatic stellate cells, which undergo a process of proliferation and senescence in the fibrogenic response to liver damage, enhances liver cirrhosis, reduces survival and increases the malignant transformation of adjacent epithelial cells into hepatocellular carcinoma. This p53-dependent senescence program involves the release of secreted proteins which skew macrophages into a tumor-inhibiting M1-state that can eliminate senescent stellate cells. In contrast, p53-deficient stellate cells secrete factors that promote M2 polarization, which is pro-tumorigenic. Our study reveals that p53 can exert a non-cell-autonomous tumor suppressor response and suggests that this occurs, in part, by its ability to influence macrophage polarization.
Non-cell-autonomous tumor suppression by p53.
Specimen part, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Ras dexamethasone-induced protein 1 is a modulator of hormone secretion in the volume overloaded heart.
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