title: Gene expression profiles of human liver cells mediated by hepatitis B virus X protein.
abstract: OBJECTIVE
  To demonstrate the gene expression profiles mediated by hepatitis B virus X protein (HBx), we characterized the molecular features of pathogenesis associated with HBx in a human liver cell model.
  
  
  METHODS
  We examined gene expression profiles in L-O2-X cells, an engineered L-O2 cell line that constitutively expresses HBx, relative to L-O2 cells using an Agilent 22 K human 70-mer oligonucleotide microarray representing more than 21,329 unique, well-characterized Homo sapiens genes. Western blot analysis and RNA interference (RNAi) targeting HBx mRNA validated the overexpression of proliferating cell nuclear antigen (PCNA) and Bcl-2 in L-O2-X cells. Meanwhile, the BrdU incorporation assay was used to test cell proliferation mediated by upregulated cyclooxygenase-2 (COX-2).
  
  
  RESULTS
  The microarray showed that the expression levels of 152 genes were remarkably altered; 82 of the genes were upregulated and 70 genes were downregulated in L-O2-X cells. The altered genes were associated with signal transduction pathways, cell cycle, metastasis, transcriptional regulation, immune response, metabolism, and other processes. PCNA and Bcl-2 were upregulated in L-O2-X cells. Furthermore, we found that COX-2 upregulation in L-O2-X cells enhanced proliferation using the BrdU incorporation assay, whereas indomethacin (an inhibitor of COX-2) abolished the promotion.
  
  
  CONCLUSIONS
  Our findings provide new evidence that HBx is able to regulate many genes that may be involved in the carcinogenesis. These regulated genes mediated by HBx may serve as molecular targets for the prevention and treatment of hepatocellular carcinoma.
authors.affiliation: Department of Cancer Research, Key Laboratory of Molecular Microbiology and Technology of Ministry of Education, Institute for Molecular Biology, College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Wei-ying
authors.initials: WY
authors.lastname: Zhang
authors.forename: Fu-qing
authors.initials: FQ
authors.lastname: Xu
authors.forename: Chang-liang
authors.initials: CL
authors.lastname: Shan
authors.forename: Rong
authors.initials: R
authors.lastname: Xiang
authors.forename: Li-hong
authors.initials: LH
authors.lastname: Ye
authors.forename: Xiao-dong
authors.initials: XD
authors.lastname: Zhang