title: In vitro transfection of the hepatitis B virus PreS2 gene into the human hepatocarcinoma cell line HepG2 induces upregulation of human telomerase reverse transcriptase.
abstract: The preS2 domain is the minimal functional unit of transcription activators that is encoded by the Hepatitis B virus (HBV) surface (S) gene. It is present in more than one-third of the HBV-integrates in HBV induced hepatocarcinoma (HCC). To further understand the functional role of PreS2 in hepatocytes, a PreS2 expression plasmid, pcS2, was constructed and stably transfected into HepG2 cells. We conducted growth curve and colony-forming assays to study the impact of PreS2 expression on cell proliferation. Cells transfected with PreS2 proliferated more rapidly and formed colonies in soft agar. PreS2 expressing cells also induced upregulation of human telomerase reverse transcriptase (hTERT) and telomerase activation by RT-PCR and the modified TRAP assay. Blocking expression of hTERT with antisense oligonuleotide reversed the growth rate in cells stably transfected with PreS2. Our data suggest that PreS2 may increase the malignant transformation of human HCC cell line HepG2 by upregulating hTERT and inducing telomerase activation.
authors.affiliation: Institute of Immunology, Shandong University School of Medicine, #44 Wenhua Xi Road, Jinan 250012, PR China.
authors.forename: Hua
authors.initials: H
authors.lastname: Liu
authors.forename: Fang
authors.initials: F
authors.lastname: Luan
authors.forename: Ying
authors.initials: Y
authors.lastname: Ju
authors.forename: Hongyu
authors.initials: H
authors.lastname: Shen
authors.forename: Lifen
authors.initials: L
authors.lastname: Gao
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Wang
authors.forename: Suxia
authors.initials: S
authors.lastname: Liu
authors.forename: Lining
authors.initials: L
authors.lastname: Zhang
authors.forename: Wensheng
authors.initials: W
authors.lastname: Sun
authors.forename: Chunhong
authors.initials: C
authors.lastname: Ma
mesh_terms: D001483:Base Sequence; D006528:Carcinoma, Hepatocellular / Q000235:genetics*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D017931:DNA Primers; D006514:Hepatitis B Surface Antigens / Q000235:genetics*; D006801:Humans; D011498:Protein Precursors / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019098:Telomerase / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D015854:Up-Regulation
chemical_list: D017931:DNA Primers; D006514:Hepatitis B Surface Antigens; D011498:Protein Precursors; D012333:RNA, Messenger; C050807:presurface protein 2, hepatitis B surface antigen; D019098:Telomerase