Profiling of growth and differentiation factor 15 regulated genes in hepatoma cells
ABSTRACT: To systematically profile the GDF15-regulated genes in hepatoma cells and to elucidate the possible role of GDF15 on biological processes, high-density oligonucleotide microarrays were hybridized with samples prepared from GDF15- or PBS-treated Huh7.5.1 cells. We found that a total of 894 genes were differentially expressed in response to GDF15 treatment based on the 2-fold cut-off range, and a majority (828 genes, about 92.6%) of the genes is up-regulated. According to the descriptions outlined by the Gene Ontology Biological Process, the differentially expressed genes were found to belong to a variety of functional categories. Two samples were included in the experiment. They are Huh7.5.1 cells treated with PBS, and Huh7.5.1 cells treated with recombinant human growth and differentiation factor 15. Twenty four hours post treatment, the total RNA was isolated from the cells. The microarray hybridization and analysis were performed by CapitalBio Corporation using the 22K Human Genome Array. Two-channel hybridizations microarray assay was performed.
Project description:To systematically profile the GDF15-regulated genes in hepatoma cells and to elucidate the possible role of GDF15 on biological processes, high-density oligonucleotide microarrays were hybridized with samples prepared from GDF15- or PBS-treated Huh7.5.1 cells. We found that a total of 894 genes were differentially expressed in response to GDF15 treatment based on the 2-fold cut-off range, and a majority (828 genes, about 92.6%) of the genes is up-regulated. According to the descriptions outlined by the Gene Ontology Biological Process, the differentially expressed genes were found to belong to a variety of functional categories. Overall design: Two samples were included in the experiment. They are Huh7.5.1 cells treated with PBS, and Huh7.5.1 cells treated with recombinant human growth and differentiation factor 15. Twenty four hours post treatment, the total RNA was isolated from the cells. The microarray hybridization and analysis were performed by CapitalBio Corporation using the 22K Human Genome Array. Two-channel hybridizations microarray assay was performed.
Project description:Chronic hepatitis B, C and D virus (HBV, HCV, HDV) infections are leading causes of liver disease and cancer worldwide. Although these viruses differ markedly in their life cycle and genomic organization, they exclusively infect hepatocytes. Recently, the sodium taurocholate cotransporting polypeptide (NTCP) was identified as the first functional receptor for HBV and HDV. Here, we report that NTCP also facilitates HCV entry into human hepatocytes, by augmenting the bile acid-mediated repression of IFN-stimulated genes (ISGs), including IFITM2 and IFITM3, to increase the susceptibility of cells to HCV entry. Furthermore, an HBV-derived preS1 peptide, known to bind NTCP and to inhibit bile acid uptake and HBV infection, inhibits HCV entry by enhancing the expression of ISGs. Our study highlights NTCP as a novel player linking bile acid metabolism to the interferon response in hepatocytes and establishes a role for NTCP in the entry process of multiple hepatotropic viruses, via distinct mechanisms. Collectively, these findings enhance our understanding of hepatitis virus-host interactions and suggest NTCP as an attractive antiviral target for HBV/HCV co-infection. Transcriptome profiling by DNA microarray of Huh7.5.1 cells transduced to express NTCP.
Project description:Silymarin (SM) is a popular botanical medicine with purported liver protective effects. SM displays multiple effects in animal models and in cell culture including prevention of liver disease, reduction of inflammation, oxidative stress, and proliferation. Despite a plethora of data indicating that SM impinges on multiple cellular signaling pathways important in inflammation and disease, no unifying mechanisms have been forwarded. To define how SM elicits so many biological effects, the current study presents the first comprehensive transcriptional profiling study of human hepatoma cells treated with SM. The intention of the study was to focus on the early transcriptional events that are associated with SM-induced inhibition of proliferation and inflammation. Collectively, the data demonstrate that SM causes a rapid transcriptional reprogramming of cells that initially manifests as energy stress and slowing of cellular metabolism, leading to inhibition of cell growth and inflammation. The effects of silymarin on liver hepatoma Huh7.5.1 cells were detected using a time course approach.
Project description:Chronic hepatitis C virus (HCV) infection is a leading cause of liver cancer. HCV propagation and oncogenicity depend in part on the phosphorylation states of its non-structural protein 5A (NS5A); however, little is known about how hypo- or hyper-phosphorylated NS5A functions. Here, we segregated hypo- from hyper-phosphorylated NS5A in HCV-infected Huh7.5.1 cells with two custom-made specific antibodies and differentiated their interacting proteins with dimethyl labeling-based quantitative proteomics. Bioinformatics analysis revealed that hyper-phosphorylated NS5A preferentially binds the polymerase II-associated factor 1 complex known to alter host gene expression involved in cancer progression. In contrast, hypo-phosphorylated NS5A binds proteins involved in host antiviral response. Moreover, we found that the hypo-phosphorylated NS5A binds DNA-dependent protein kinase catalytic subunit (DNA-PKcs) predicted to phosphorylate NS5A at serine 232, a key amino acid that governs NS5A transition from hypo- to hyper-phosphorylation state. Inhibition of DNA-PKcs with an inhibitor or via gene-specific knockdown significantly reduced serine 232 phosphorylation and NS5A hyper-phosphorylation. Collectively, we have identified a protein kinase that regulates a delicate balance of NS5A between hypo- and hyper-phosphorylation states respectively involved in host antiviral responses and liver cancer progression.
Project description:Tumor-associated macrophages (TAMs) are known to be involved in progression, angiogenesis and motility of various cancers. We have previously reported the association between increased number of infiltrating TAMs with tumor progression and poor prognosis in esophageal squamous cell carcinomas (ESCCs). To study roles of TAMs in ESCC, we first exposed peripheral blood monocytes (PBMo) derived macrophages from healthy volunteers to conditioned media of TE series human ESCC cell line (TECM) and confirmed the induction of expression of M2 macrophage marker, CD204, and protumorigenic factors, interleukin (IL)-10, VEGFA and MMPs. Next, we compared gene expression profile between PBMo-derived macrophages and PBMo-derived macrophages stimulated with TECM by cDNA microarray. Based on the result, we focused on growth differentiation factor 15 (GDF15) among highly expressed genes including IL-6, IL-8 and CXCL1. Immunohistochemical study on 70 cases of surgically resected ESCCs revealed that GDF15 was detected not only in macrophages but also in cancer cells. High expression of GDF15 in ESCCs was significantly correlated with more malignant phenotypes including lymph and blood vessel invasion, lymph node metastasis as well as clinical stages. Patients with high expression of GDF15 showed poor disease-free survival (p = 0.011) and overall survival (p = 0.041). Furthermore, we found that recombinant human GDF15 promote cell proliferation and phosphorylation of both Akt and Erk1/2 in ESCC cell lines in vitro. These results indicate that GDF15 is secreted by both TAMs and cancer cells in tumor microenvironment and is associated with aberrant growth and poor prognosis of human ESCC. We exposed PBMo-derived macrophages from healthy volunteers to TECM and observed their acquisition of TAM-like characters in this study. We further investigated specific cancer-associated gene expression profile in TECM induced TAM-like macrophages by cDNA microarray analysis.
Project description:The Flaviviridae is a family of enveloped viruses with a positive-sense single-stranded RNA genome. It contains many viruses that threaten human health, such as Japanese encephalitis virus (JEV) and yellow fever virus (YFV) of the genus Flavivirus as well as hepatitis C virus of the genus Hepacivirus. Cell culture systems highly permissive for the Flaviviridae viruses are very useful for their isolation, propagation, and diagnosis, an understanding of their biology, and the development of vaccines and antiviral agents. Previously, we isolated a human hepatoma HuH-7-derived cell clone, Huh7.5.1-8, which is highly permissive to hepatitis C virus infection. Here, we have characterized flavivirus infection in the Huh7.5.1-8 cell line by comparing with that in the African green monkey kidney-derived Vero cell line, which is permissive for a wide spectrum of viruses. Upon infection with JEV, Huh7.5.1-8 cells produced a higher amount of virus particles early in infection and were more susceptible to virus-induced cell death than Vero cells. Similar outcomes were obtained when the cells were infected with another flavivirus, YFV (17D-204 strain). Quantification of cellular and extracellular viral RNA revealed that high JEV production in Huh7.5.1-8 cells can be attributed to rapid viral replication kinetics and efficient virus release early in infection. In a plaque assay, Huh7.5.1-8 cells developed JEV plaques more rapidly than Vero cells. Although this was not the case with YFV plaques, Huh7.5.1-8 cells developed higher numbers of YFV plaques than Vero cells. Sequence analysis of cDNA encoding an antiviral RNA helicase, RIG-I, showed that Huh7.5.1-8 cells expressed not only a full-length RIG-I mRNA with a known dominant-negative missense mutation but also variants without the mutation. However, the latter mRNAs lacked exon 5/6-12, indicating functional loss of RIG-I in the cells. These characteristics of the Huh7.5.1-8 cell line are helpful for flavivirus detection, titration, and propagation.
Project description:Protein kinase R (PKR), a sensor of double-stranded RNA, plays an important role in the host response to viral infection. Hepatitis C genotype 2a virus (HCV2a) has been shown to induce PKR activation to suppress the translation of antiviral interferon stimulated genes (ISGs), suggesting that PKR inhibitor can be beneficial for treating chronically HCV-infected patients in conjunction with interferon alpha and ribavirin. However, in this study, we found that PKR inhibition using siRNA PKR, shRNA PKR or PKR inhibitor enhanced HCV 1a replication and rendered Huh7.5.1 cells more susceptible to HCV1a infection. Additionally, PKR silencing suppressed NF-kB activation and NF-kB mediated STAT1 phosphorylation in Huh7.5.1 cells and HCV1a persistently infected Huh7.5.1 cells (2HDD4). These effects were accompanied by a reduction of interferon beta response and thereby enhanced HCV1a replication in Huh7.5.1 cells. We conclude that host cells can employ PKR activation to restrict HCV1a replication through regulation of NF-kB expression.