title: [Structural and functional analysis of 2.2 kb spliced variant of hepatitis B virus genomes isolated from liver tissues from hepatocellular carcinoma patients].
abstract: BACKGROUND
  To study the structure and function of 2.2 kb spliced variant of HBV genome from liver tissues of hepatocellular carcinoma patients.
  
  
  METHODS
  HBV genomes were amplified by using PCR from paired hepatocellular carcinoma tissues and peritumor tissues. The 3.2 kb full-length HBV genome and 2.2 kb spliced variant were separately cloned and sequenced. Hep G2 cells were co-transfected with full-length HBV DNA and 2.2 kb spliced variant, and after transfection, HBV DNAs from intracellular core particles were harvested and specific primers were used in PCR to evaluate the interactions between spliced variant and full-length counterpart in replication.
  
  
  RESULTS
  Semi-quantification by scanning density showed that 2.2 kb spliced variant was present in all tumor and peri-tumor samples studied. Sequence analyes revealed that the 5  terminus packaging signal for pregenomic and X and PreC/C genes were retained. When full-length HBV DNA was co-transfected with 2.2 kb, the replication signal of 3.2 kb HBV genome was increased 3-7 times.
  
  
  CONCLUSIONS
  The 2.2 kb HBV spliced variant was present in liver tissues, and relative content was higher in tumor tissues than that in the peri-tumor tissues. This spliced variant could enhance the replication of full-length HBV genome, which suggested the possible role of the variant in the pathogenesis of development of hepatocellular carcinoma.
authors: Department of Molecular Virology, Medical Center of Fudan University, Shanghai 200032, China.
authors: Xu
authors: X
authors: Lin
authors: Yumei
authors: Y
authors: Wen
authors: Dafang
authors: D
authors: Wan
authors: Gengsun
authors: G
authors: Qian
authors: Jianren
authors: J
authors: Gu
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000821:virology*; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D014644:Genetic Variation; D016679:Genome, Viral; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D008099:Liver / Q000821:virology*; D008113:Liver Neoplasms / Q000821:virology*; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000032:analysis; D017422:Sequence Analysis, DNA
chemical_list: D004279:DNA, Viral; D012367:RNA, Viral