[Structural and functional analysis of 2.2 kb spliced variant of hepatitis B virus genomes isolated from liver tissues from hepatocellular carcinoma patients].
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.
Lin
Xu
X
Department of Molecular Virology, Medical Center of Fudan University, Shanghai 200032, China.
Wen
Yumei
Y
Wan
Dafang
D
Qian
Gengsun
G
Gu
Jianren
J
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
D004279:DNA, Viral; D012367:RNA, Viral