title: The hepatitis B virus X protein up-regulates lymphotoxin alpha expression in hepatocytes.
abstract: Hepatitis B virus X protein (HBx) is involved in intrahepatic inflammatory processes by inducing several pro-inflammatory cytokines. It has been suggested that these inflammatory processes play an important role in causing hepatocarcinogenesis. In this study, we investigated the role of HBx in the expression of lymphotoxin alpha (LTalpha) in hepatoma cells such as Huh-7 and Chang. Our experiments showed that (i) transient HBx expression in Huh-7 cells up-regulated LTalpha mRNA expression; (ii) this up-regulation was predominantly affected by HBx-induced nuclear factor-kappaB (NF-kappaB) activation. In addition, the HBx-induced NF-kappaB activation was decreased by the treatment of LTalpha neutralizing antibodies in a dose-dependent manner. We conclude that HBx up-regulates LTalpha expression at the transcriptional level through an NF-kappaB-dependent mechanism and, therefore, the up-regulated LTalpha may be secreted and involved in the HBx-induced NF-kappaB activation.
authors.affiliation: School of Biological Sciences, Seoul National University, Seoul 151-747, Republic of Korea.
authors.forename: Sang Hun
authors.initials: SH
authors.lastname: Lee
authors.forename: Sung Gyoo
authors.initials: SG
authors.lastname: Park
authors.forename: Seung Oe
authors.initials: SO
authors.lastname: Lim
authors.forename: Guhung
authors.initials: G
authors.lastname: Jung
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000473:pathology; D045744:Cell Line, Tumor; D015967:Gene Expression Regulation, Viral; D022781:Hepatocytes / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D006801:Humans; D008233:Lymphotoxin-alpha / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D015534:Trans-Activators / Q000502:physiology*; D014162:Transfection; D015854:Up-Regulation; D054334:Viral Regulatory and Accessory Proteins
chemical_list: D008233:Lymphotoxin-alpha; D016328:NF-kappa B; D015534:Trans-Activators; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein