Chemokine Expression Profiles of Human Hepatoma Cell Lines Mediated by Hepatitis B Virus X Protein

Abstract

The hepatitis B virus X protein (HBx), which is encoded by hepatitis B virus (HBV), plays crucial roles in the tumorigenesis of HBV associated hepatocellular carcinoma (HCC). Recent studies suggest that the HBx is involved in regulation of host immune cytokines and chemokines in HBV-associated HCC patients. However, effects of the HBx on autocrine chemokine expression profiles of hepatoma cells, which were shown in modulation of tumor-immune cell interactions, have not been investigated comprehensively. In the present study, human hepatoma cell lines SMMC-7721 and HepG2 were transfected with HBx-expressing plasmid. Human chemokine antibody array 1 (RayBio®), which simultaneously detects 38 chemokine factors, was used to determine chemokine expression profiles. Real-time polymerase chain reaction (real-time PCR) was used to further confirm the differential expression of chemokines. Chemokine antibody array revealed that all 38 chomekines were found to be expressed by SMMC-7721 and HepG2 cell lines. Interleukin-8 (IL-8) was obviously up-regulated, and epithelial neutrophil-activating protein 78 (ENA78), eosinophil chemotactic protein-1 (Eotaxin-1), monocyte chemotactic protein-1 (MCP-1), MCP-2, MCP-3 and macrophage inflammatory protein-3β (MIP-3β) were significantly declined in both cell lines following transfection of HBx-expressing plasmid. Other chemokines showed little or no significant changes. HBx-induced differential chemokine expression levels were validated by real-time PCR. Hierarchical cluster analysis identified a distinction of chomekine expression profiles between HBX-expressing hepatoma cell lines and controls. Our findings provide new evidence that HBx is able to selectively regulate chomekines in hepatoma cells that may be involved in the regulation of tumor-immune cell interactions.

Effect of HBx on inflammation and mitochondrial oxidative stress in mouse hepatocytes

“…HBx selectively regulates other pro-inflammatory cytokines, such as IL-1β, IL-18 and IL-23, and participates in the regulation of immune cell interactions (49,50). These cytokines serve a role in the development and progression of liver cancer.…”

Slow reduction of IP-10 Levels predicts HBeAg seroconversion in chronic hepatitis B patients with 5 years of entecavir treatment

“…Cytokines not only inhibit viral replication, but determine the predominant pattern of the host immune response910. Chemokines, a family of small cytokines, direct the migration of circulating leukocytes to sites of inflammation or injury, and enhance the phagocytic power of the inflammatory cells1112. As the control of cytokine secretion is highly complex and the interactions between cytokines and their receptors are widespread throughout multiple regulatory networks, screening for multiple biomarkers may elucidate the immunopathogenesis of HBV infection and predict responses to antiviral therapy.…”

Hepatitis B virus X protein in liver tumor microenvironment

“…These cytokines function in the pathological processes underlying HCC development. For instance, IL-8 regulates tumor growth and the malignant transformation of hepatocytes; additionally, it has been associated with HCC invasion and metastasis [26, 78]. Serum levels of IL-18, a novel pro-inflammatory cytokine, are often elevated in patients with HBV-HCC and may have an application as a prognostic indicator in these patients [79].…”

“…Stimulating the production of IL-6 to mediate HCC developmentIn vitro studies of transfected cell lines L02 and SMMC-7721Xiang et al [25]2. Upregulating the expression of IL-8 to promote tumor growth and the malignant transformation of hepatocytesIn vitro studies of transfected cell lines SMMC-7721 and HepG2 cellsWang et al [26]3. Regulating other pro-inflammatory cytokines such as IL-18, IL-23, and TNF-α to induce liver chronic inflammationIn vivo studies of clinical specimens and in vitro studies of transfected cell lines HepG2 and Huh-7 cellsXia et al [27]TNF-α1.…”