Transcriptional gene expression profile in hepatocarcinoma cells induced by acetylsalicylic acid (ASA) in hepatitis C virus (HCV)-subgenomic replicon system.

Abstract

e22016 Background: It has been demonstrated that ASA treatment could down-regulate in vitro HCV expression in hepatocarcinoma cells (~50%, p 0.05). However, the signaling pathway induced during ASA antiviral effect has not been elucidated. We analyzed the transcriptional expression profile of Huh-7-HCV-subgenomic replicon cells in presence or absence of ASA in order to identify the signaling pathway and the molecular mechanisms involved in the antiviral effect induced by ASA on HCV expression. Methods: Huh-7-HCV-replicon cells (hepatocarcinoma) were exposed to 4 mM ASA from 24 to 72 hours. Total RNA was isolated, quantified and validated by capillary electrophoresis. After that, we performed a retrotranscription in vitro. Synthesized transcripts were marked with biotin, purified, fragmentized and hybridized in HG-U133 Plus 2 Gene Expression. Hybridization signals were captured with Gen Chip 3000 7G Scanner and analyzed by Expression Console and Dchit Software. Results: After normalization, we obtained hierarchical maps with differentially-expressed genes. Among genetic targets over-expressed, the following stood out CCAAT-enhancer-binding proteins (C/EBP), interleukine-8 (IL-8), cytochrome P450 (CyP450) and methallothioneins (MT) genes were found. Among down-regulated genes we identified ribonucleotide reductase (RR) and superoxide dismutase (SOD) genes. Some of these genes have been previously associated with oxidative stress regulation. All results were validated by real time PCR. Conclusions: We observed that ASA modulates the expression of genes associated with antioxidant role as SOD and methallothioneins. Antioxidant agents can inhibit virus proliferation. HCV decreased antioxidant defense, which promotes the development of hepatic complications caused by HCV infection, including liver cancer. Therefore, ASA could be inducing an antioxidant environment regulating HCV replication. This study provides a tool for identifying novel host factors in hepatocarcinoma cells involved in the antiviral effect regulated by ASA against HCV and improves our understanding of the regulatory mechanism of HCV replication.