EGAS00001003310 - samples
Ontology highlight
ABSTRACT:
PROVIDER: EGAD00001004484 | EGA |
REPOSITORIES: EGA
Similar Datasets
Project description:Adeno-associated virus (AAV) is a defective mono-stranded DNA virus, endemic in human population (40-80%). AAV infection has long been considered as non-pathogenic1, however few years ago we reported for the first time recurrent clonal AAV2 insertion in the pathogenesis of human hepatocellular carcinoma (HCC) developed on normal liver. These clonal viral insertions target cancer driver genes, including CCNA2, CCNE1, TERT, TNFSF10 and MLL4, leading to their overexpression. The viral inserted sequences involved in almost all the cases the 3’ inverse tandem repeat (ITR) of AAV2, which is important for virus integration in host DNA and exhibits a promoter/enhancer activity. Here, we used RNA sequencing (RNA-seq) to investigate their functional impact on the tissue, such as fusion transcript generation events.
| EGAS00001003310 | EGA
Project description:<p>Hepatitis B virus (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC). In this study we sequenced the whole genome (~80X) and transcriptome of tumor and non-tumor samples from four HCC patients and identified over two hundred HBV integration sites. We found significant clonal expansion of HBV-integrated hepatocytes specifically in the tumor samples. We observed a diverse collection of genomic perturbations near viral integration sites, including gene disruption, viral promoter-driven human transcription, viral-human transcript fusion and DNA copy number alteration. We also sequenced one patient at ultra-high coverage (~240X) to build the most comprehensive HBV-integration landscape yet attempted. Our data suggest that the viral integration significantly expands carcinogenic opportunities in HBV-infected individuals.</p>
| phs000384 | dbGaP
Project description:AAV gene therapy has recently been approved for clinical use and shown to be efficacious and safe in a growing number of clinical trials. However, the safety of AAV as a gene therapy has been challenged by a few studies that documented hepatocellular carcinoma (HCC) after AAV gene delivery in mice. The association between AAV and HCC has been difficult to reconcile and is the subject of intense debate because numerous AAV studies have not reported toxicity. Here, we report a comprehensive study of HCC in a large number of mice following therapeutic AAV gene delivery. Using a sensitive high-throughput integration site-capture technique and global expressional analysis, we found that AAV integration into the Rian locus and the over-expression of a proximal gene, Rtl1, were associated with HCC. In addition, we identify a number of genes with differential expression that maybe useful in the study, diagnosis and treatment of HCC. We demonstrate that AAV vector dose, enhancer-promoter selection, and the timing of gene delivery are the defining factors in AAV-mediated insertional mutagenesis. Our results help explain the AAV-mediated genotoxicity previously observed and have important implications for the design of both safer AAV vectors and gene therapy studies. To investigate the possibility that insertional mutagenesis by AAV contributed to the development of HCC, we collected normal and tumor tissues from adult mouse livers that received AAV injection at a neonatal stage.
2015-01-01 | E-GEOD-57597 | biostudies-arrayexpress
Project description:AAV gene therapy has recently been approved for clinical use and shown to be efficacious and safe in a growing number of clinical trials. However, the safety of AAV as a gene therapy has been challenged by a few studies that documented hepatocellular carcinoma (HCC) after AAV gene delivery in mice. The association between AAV and HCC has been difficult to reconcile and is the subject of intense debate because numerous AAV studies have not reported toxicity. Here, we report a comprehensive study of HCC in a large number of mice following therapeutic AAV gene delivery. Using a sensitive high-throughput integration site-capture technique and global expressional analysis, we found that AAV integration into the Rian locus and the over-expression of a proximal gene, Rtl1, were associated with HCC. In addition, we identify a number of genes with differential expression that maybe useful in the study, diagnosis and treatment of HCC. We demonstrate that AAV vector dose, enhancer-promoter selection, and the timing of gene delivery are the defining factors in AAV-mediated insertional mutagenesis. Our results help explain the AAV-mediated genotoxicity previously observed and have important implications for the design of both safer AAV vectors and gene therapy studies. To investigate the possibility that insertional mutagenesis by AAV contributed to the development of HCC, we collected normal and tumor tissues from adult mouse livers that received AAV injection at a neonatal stage.
2015-09-01 | E-GEOD-61632 | biostudies-arrayexpress
Project description:We describe and functionally characterize a previously unknown liver-specific enhancer-promoter element in the wild-type AAV2 (wtAAV2) genome lying between the cap stop codon and right-hand inverted terminal repeat (ITR). Remarkably, this element falls within the 163-nucleotide common insertion region of the AAV genome implicated in HCC oncogenesis, thereby providing a mechanistic explanation for the participation of AAV integration events in the development of HCC.
2017-06-12 | GSE93341 | GEO
Project description:Studying hepatitis delta virus (HDV) and developing new treatments is hampered by the absence limited availability of small animal models. Here a description of a robust mouse model of HDV infection that mimics several important characteristics of the human disease is presented. HDV- and HBV-replication competent genomes were delivered to the mouse liver using adeno-associated viruses (AAV) (AAV-HDV and AAV-HBV). Viral load, antigen expression and genomes were quantified at different time points after AAV injection. Furthermore, liver pathology, genome editing, and the activation of the innate immune response were evaluated. AAV-HDV infection initiated HDV replication in mouse hepatocytes. Genome-editing was confirmed by the presence of small and large-HDV-antigens and sequencing. Viral replication was detected for 45 days, even after the AAV-HDV vector had almost disappeared. In the presence of HBV, HDV infectious particles were detected in serum. Furthermore, as observed in patients, co-infection was associated with the reduction of HBV antigen expression and the onset of liver damage that included the up/down-regulation of genes involved in the development of liver pathologies. HDV replication induced a sustained type-I IFN response, which was significantly reduced in immunodeficient mice and almost absent in MAVS-deficient mice. The animal model described here reproduces important characteristics of human HDV infection and provides a valuable tool for characterizing the viral infection and for developing new treatments. Furthermore, MAVS was identified as a main player in HDV detection and adaptive immunity was found to be involved in the amplification of the innate immune response.
2017-06-30 | GSE98342 | GEO
Project description:Hepatitis C virus (HCV)-induced chronic liver disease is one of the leading causes of hepatocellular carcinoma (HCC). However, the molecular mechanisms underlying HCC development following chronic HCV infection remain poorly understood. MicroRNAs (miRNAs) play an important role in cellular homeostasis within the liver and deregulation of the miRNome has been associated with liver disease including HCC. While host miRNAs are essential for HCV replication, viral infection in turn appears to induce alterations of intrahepatic miRNA networks. Although the cross-talk between HCV and liver cell miRNAs most likely contributes to liver disease pathogenesis, the functional involvement of miRNAs in HCV-driven hepatocyte injury and HCC remains elusive. Here, we combined a hepatocyte-like based model system, high-throughput small RNA-sequencing, computational analysis and functional studies to investigate HCV-miRNA interactions that may contribute to liver disease and HCC. Profiling analyses indicated that HCV infection differentially regulated the expression of 72 miRNAs by at least two-fold including miRNAs that were previously described to target genes associated with inflammation, fibrosis and cancer development. Further investigation demonstrated that miR-146a-5p was consistently increased in HCV-infected hepatocyte-like cells and primary human hepatocytes as well as in liver tissues from HCV-infected patients. Genome-wide microarray and computational analyses indicated that miR-146a-5p over-expression is related to liver disease and HCC development. Furthermore, we showed that miR-146a-5p positively impacts on late steps of the viral replication cycle thereby increasing HCV infection. Collectively, our data indicate that the HCV-induced increase in miR-146a-5p expression both promotes viral infection and is relevant for pathogenesis of liver disease.
2016-05-09 | GSE74014 | GEO
Project description:Hepatitis C virus (HCV)-induced chronic liver disease is one of the leading causes of hepatocellular carcinoma (HCC). However, the molecular mechanisms underlying HCC development following chronic HCV infection remain poorly understood. MicroRNAs (miRNAs) play an important role in cellular homeostasis within the liver and deregulation of the miRNome has been associated with liver disease including HCC. While host miRNAs are essential for HCV replication, viral infection in turn appears to induce alterations of intrahepatic miRNA networks. Although the cross-talk between HCV and liver cell miRNAs most likely contributes to liver disease pathogenesis, the functional involvement of miRNAs in HCV-driven hepatocyte injury and HCC remains elusive. Here, we combined a hepatocyte-like based model system, high-throughput small RNA-sequencing, computational analysis and functional studies to investigate HCV-miRNA interactions that may contribute to liver disease and HCC. Profiling analyses indicated that HCV infection differentially regulated the expression of 72 miRNAs by at least two-fold including miRNAs that were previously described to target genes associated with inflammation, fibrosis and cancer development. Further investigation demonstrated that miR-146a-5p was consistently increased in HCV-infected hepatocyte-like cells and primary human hepatocytes as well as in liver tissues from HCV-infected patients. Genome-wide microarray and computational analyses indicated that miR-146a-5p over-expression is related to liver disease and HCC development. Furthermore, we showed that miR-146a-5p positively impacts on late steps of the viral replication cycle thereby increasing HCV infection. Collectively, our data indicate that the HCV-induced increase in miR-146a-5p expression both promotes viral infection and is relevant for pathogenesis of liver disease. To explore the functional relevance of miR-146a-5p up-regulation, we performed a genome-wide transcriptomic analysis of hepatocyte-like cells upon ectopic miR-146a-5p expression.
2016-05-09 | GSE79340 | GEO
Project description:We have shown that intravenous injection of HDAC3 floxed mice with adeno-associated virus (AAV) expressing Cre depletes hepatic HDAC3, upregulates lipogenic gene expression, and causes fatty liver. When AAV-Flag-HDAC3 wild-type (WT) is co-injected along with AAV-Cre, the exogenous HDAC3 is expressed at endogenous levels and can completely rescue fatty liver phenotype. Here we profile transcriptome of the rescued WT livers in comparison with HDAC3-depleted (KO) livers. 4-months old C57BL/6 male mice were co-injected with AAV-Cre or AAV-Cre plus AAV-Flag-HDAC3. Mice were fed ad libitum and harvested at 5 pm (ZT10) at 2-weeks post-injection. Liver total RNA was extracted and hybridized to Affymetrix Mouse Gene 1.0ST array.
2013-11-25 | E-GEOD-49386 | biostudies-arrayexpress
Project description:We have previously developed a modified iteration of a viral chromosome conformation capture (V3C-seq) assay to show that the autonomous parvovirus Minute Virus of Mice (MVM) localizes spatially with cellular sites of DNA damage to establish viral replication centers. Similar V3C-seq assays to map AAV genome localization show that both replicating and non-replicating AAV2 genomes in the absence of helper virus colocalize with cellular sites of DNA damage. The AAV non-structural protein Rep 68/78, when ectopically expressed in the absence of viral infection or during AAV2 infection in the absence of helper proteins also localizes to cellular sites of DNA damage. Strikingly however, recombinant AAV gene therapy vector genomes derived from AAV do not colocalize with AAV and Rep at cellular DDR sites.
2021-10-20 | GSE178316 | GEO