ABSTRACT: Hepatitis B virus (HBV) has been clearly recognized as an etiological factor for hepatocellular carcinoma (HCC). HBV encodes the potentially oncogenic HBx protein. We aimed to elucidate the molecular mechanism of HCC caused by HBx and to discover the biomarker related to HCC by HBx. Three experimental groups, 3, 9 and 13 month aged HBx Tg mice and age matched normal wild type B6 mouse which have same background of HBx Tg mice were used to find differentially expressed genes during HCC. Keywords: Genetic modification 3-month-old, 9-month-old, 13-month-old wild type B6 mice vs 3-month-old, 9-month-old, 13-month-old HBx transfected mice; Biological replicates at each timepoint; 9 controls vs 9 HBx-mice
Project description:Hepatitis B virus (HBV) infection promotes liver cancer initiation by inducing inflammation and cellular stress, but its impact in established tumors is not well understood. We used affinity purification mass spectrometry to comprehensively map a network of 145 physical interactions between HBV and human proteins in hepatocellular carcinoma (HCC). A subset of the host factors targeted by HBV proteins are preferentially mutated in non-HB¬V-associated HCC suggesting that their interaction with HBV influences HCC biology. These include proteins involved in mRNA splicing, mitogenic signaling and DNA repair, with the latter set interacting with the HBV oncoprotein X (HBx). We show that HBx remodels the PP2A phosphatase complex by excluding striatin regulatory subunits from the PP2A holoenzyme. We find that HBx effects on PP2A cause Hippo kinase activation, particularly in cells with high striatin levels. In parallel, HBx activates mTOR complex 2 (mTORC2) to prevent YAP degradation. mTORC2 effects on YAP can be observed in human HCC specimens and mouse HCC models and can be targeted with mTOR kinase inhibitors. Thus, HBV interaction with host proteins rewires HCC signaling rather than directly activating mitogenic pathways. These findings provide a new paradigm for the cellular effects of a tumor promoting virus and support a model where HBV may have therapeutic actionable effects on HCC biology.
Project description:Hepatitis B virus (HBV) infection could cause hepatitis, liver cirrhosis and hepatocellular carcinoma. HBV-mediated pathogenesis is only partially understood, but X protein (HBx) reportedly possesses oncogenic potential. Exosomes are small membrane vesicles with diverse functions released by various cells including hepatocytes, and HBV harnesses cellular exosome biogenesis and export machineries for virion morphogenesis and secretion. Therefore, HBV infection might cause changes in exosome contents with functional implications for both virus and host. In this project, exosome protein content changes induced by HBV and HBx were quantitatively analyzed by SILAC/LC-MS/MS. Exosomes prepared from SILAC-labeled hepatoma cell line Huh-7 transfected with HBx, wildtype or HBx-null HBV replicon plasmids were analyzed by LC-MS/MS.
Project description:Hepatitis B Virus (HBV) remains a major public health problem, and is a major cause liver cancer worldwide. HBV infection in vivo requires the function of the HBx protein, which facilitates expression of viral genes from the episomal genome by an unknown mechanism. Evidence suggests that HBx functions as a targeting subunit for the CRL4 E3 ubiquitin ligase, redirecting the complex to target and degrade an unknown host restriction factor. We used substrate trapping proteomics to search for ubiquitylation substrates of HBx. We used MLN4924 to block CRL activity and stabilize interactions between HBx and its substrates. We then performed APMS to identify bound proteins and potential substrates.
Project description:Hepatitis B virus (HBV) has been clearly recognized as an etiological factor for hepatocellular carcinoma (HCC). HBV encodes the potentially oncogenic HBx protein. We aimed to elucidate the molecular mechanism of HCC caused by HBx and to discover the biomarker related to HCC by HBx. Three experimental groups, 3, 9 and 13 month aged HBx Tg mice and age matched normal wild type B6 mouse which have same background of HBx Tg mice were used to find differentially expressed genes during HCC. Keywords: Genetic modification
Project description:MicroRNA expression profiling of human Hep3B and HepG2 HCC cells comparing parental cancer cells with stable HBx-transfectants In this study,two pairs of control and HBx-overexpressing HCC cells were used to acquire expression profiles of a total of microRNA. miRNA microarray analysis was performed with mirVana miRNA Bioarrays V1 (Ambion) according to the manufacturerM-bM-^@M-^Ys instructions
Project description:Mature microRNA expression profiling of HBx-expressing HepG2 cells versus Control cells under UV stress The mature microRNA expression profile of HBx-expressing HepG2 cells versus control cells in three independent biological repeated experiments. This study focuses only on human sequences. The complete data matrix is linked below as a supplementary file.
Project description:Hepatoarcinogenesis is a slow and multistep process. We used Hepatitis B virus X antigen (HBx) induced Hepatocellular carcinoma (HCC) as model. We also identify the biomarkers, the pathways and networks underlying HCC formation in this animal model. We analyzed the events from the early, middle, and late stages, in order to predict and prevent the development of cancer. At each specific stage, we analyzed the expression level that differed at least two-fold between HBx transgenic and wild-type mouse liver. Statistical approaches were used to identify genes displaying an increasing or decreasing trend throughout hepatocarcinogenesis. The liver was excised from 6-week-, 8-month-, 12-month-, 14-month-, and 16-month-old HBx transgenic mice (A106 strain) and RNA samples were isolated. In both 14-month- and 16-month-old mice, samples were obtained from both the tumor tissue and the normal.
Project description:A genome-wide integrated methylome and transcriptome analysis of the early stage of hepatocellular carcinoma development that induced by HBx. The HBV x (HBx) protein, which plays a critical role in the development of HCC, was shown to interact with several epigenetic factors, such as DNMT3A and HDAC1. Most HBx transgenic (TG) mice spontaneously develop HCC at about 1 year of age, providing genetic validation of the oncogenic potential of HBx even in the absence of viral integration and chronic inflammation. Therefore, it would be intriguing to study the regulatory role of HBx in the epigenome and its impact on HCC development. We performed a genome-wide analysis to examine the differences in DNA methylation patterns and RNA transcriptions between cancer and normal liver cells. High-throughput sequencing analysis of MIRA (methylated CpG island recovery assay) and mRNA at 3 mouth old age mouse liver
Project description:Chronic hepatitis B virus (HBV) remains to be the most common risk factor of hepatocellular carcinoma (HCC). While previous work has primarily focussed on understanding the direct and indirect mechanisms of Hepatitis B virus X protein (HBx)-mediated hepatocarcinogenesis, from genetic and epigenetic perspectives, its influence on RNA modification mediated onset of liver malignancies is less well understood. This study explored the role of HBV-encoded HBx in altering the m6A methylome profile and its implications on the pathogenesis of HCC. We established HBx-expressing stable HCC cell lines, Huh7-HBx and HepG2-HBx, and explored the transcriptomic and epitranscriptomic profiles by RNA-seq and MeRIP-seq, respectively. Preliminary results suggest that HBx promotes liver cell proliferation, migration, survival and overall m6A methylation in HCC cells and is involved in modulating the extracellular matrix. We show that HBx mediates liver cell transformation by upregulating KIAA1429 methyltransferase. HBx also drives the expression and hypermethylation of the extracellular matrix protein HSPG2/Perlecan and promotes tumourigenesis. Furthermore, we observed a potential interaction between KIAA1429 and HSPG2 in HCC liver cancer cells and demands further investigation.
Project description:Chronic hepatitis B virus (HBV) remains to be the most common risk factor of hepatocellular carcinoma (HCC). While work has primarily focussed on understanding the direct and indirect mechanisms of Hepatitis B virus X protein (HBx) mediated hepatocarcinogenesis, from genetic and epigenetic perspectives, its influence on RNA modification mediated onset of liver malignancies is less well understood. This study explored the role of HBV-encoded HBx in altering the m6A methylome profile and its implications on the pathogenesis of HCC. We established HBx expressing stable HCC cell lines, Huh7-HBx and HepG2-HBx, and explored the transcriptomic and epitranscriptomic profiles by RNA-seq and MeRIP-seq, respectively. Preliminary results suggest that HBx promotes liver cell proliferation, migration, survival and overall m6A methylation in HCC cells and is involved in modulating the extracellular matrix. We show that HBx mediates liver cell transformation by upregulating KIAA1429 methyltransferase. HBx also drives the expression and hypermethylation of the extracellular matrix protein HSPG2/Perlecan and promotes tumourigenesis. Our findings indicate a potential interaction between KIAA1429 and HSPG2, thus could be novel targets in combating HBx-driven HCC and warrants further investigation.