title: Alteration of gene expression in human hepatocellular carcinoma with integrated hepatitis B virus DNA.
abstract: OBJECTIVE
  Integration of hepatitis B virus (HBV) DNA into the human genome is one of the most important steps in HBV-related carcinogenesis. This study attempted to find the link between HBV DNA, the adjoining cellular sequence, and altered gene expression in hepatocellular carcinoma (HCC) with integrated HBV DNA.
  
  
  METHODS
  We examined 15 cases of HCC infected with HBV by cassette ligation-mediated PCR. The human DNA adjacent to the integrated HBV DNA was sequenced. Protein coding sequences were searched for in the human sequence. In five cases with HBV DNA integration, from which good quality RNA was extracted, gene expression was examined by cDNA microarray analysis.
  
  
  RESULTS
  The human DNA sequence successive to integrated HBV DNA was determined in the 15 HCCs. Eight protein-coding regions were involved: ras-responsive element binding protein 1, calmodulin 1, mixed lineage leukemia 2 (MLL2), FLJ333655, LOC220272, LOC255345, LOC220220, and LOC168991. The MLL2 gene was expressed in three cases with HBV DNA integrated into exon 3 of MLL2 and in one case with HBV DNA integrated into intron 3 of MLL2. Gene expression analysis suggested that two HCCs with HBV integrated into MLL2 had similar patterns of gene expression compared with three HCCs with HBV integrated into other loci of human chromosomes.
  
  
  CONCLUSIONS
  HBV DNA was integrated at random sites of human DNA, and the MLL2 gene was one of the targets for integration. Our results suggest that HBV DNA might modulate human genes near integration sites, followed by integration site-specific expression of such genes during hepatocarcinogenesis.
authors.affiliation: Department of Hepatology, Osaka City University Graduate School of Medicine, Osaka, Japan. atamori@med.osaka-cu.ac.jp
authors.forename: Akihiro
authors.initials: A
authors.lastname: Tamori
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Yamanishi
authors.forename: Shuichi
authors.initials: S
authors.lastname: Kawashima
authors.forename: Minoru
authors.initials: M
authors.lastname: Kanehisa
authors.forename: Masaru
authors.initials: M
authors.lastname: Enomoto
authors.forename: Hiromu
authors.initials: H
authors.lastname: Tanaka
authors.forename: Shoji
authors.initials: S
authors.lastname: Kubo
authors.forename: Susumu
authors.initials: S
authors.lastname: Shiomi
authors.forename: Shuhei
authors.initials: S
authors.lastname: Nishiguchi
mesh_terms: D000328:Adult; D000368:Aged; D001483:Base Sequence; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000821:virology; D004273:DNA, Neoplasm / Q000737:chemistry / Q000235:genetics; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics*; D005091:Exons / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006509:Hepatitis B / Q000235:genetics / Q000821:virology; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D007680:Kidney Neoplasms / Q000235:genetics* / Q000821:virology; D020930:MAP Kinase Kinase Kinases / Q000235:genetics; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D016662:Virus Integration / Q000235:genetics
chemical_list: D004273:DNA, Neoplasm; D004279:DNA, Viral; D012333:RNA, Messenger; D020930:MAP Kinase Kinase Kinases; C093290:MAP3K10 protein, human