title: [Inhibition of hepatitis B virus S gene and C gene expression by different 10-23 DNAzymes substrate-recognition domains].
abstract: OBJECTIVE
  To explore the inhibition effects of 10-23 DNAzymes with different substrate-recognition domains targeting hepatitis B virus (HBV) S gene and C gene expression in 2.2.15 cells.
  
  
  METHODS
  10-23 DNAzymes with different substrate-recognition domains specific to HBV S gene open reading frame (ORF) A(157)UG and HBV C gene ORF A(1816)UG were designed and synthesized, respectively. Different 10-23 DNAzymes were transfected into 2.2.15 cells which is a stable HBV producing cell line. HBsAg and HBeAg secreted into culture media were detected by radioimmunoassay (RIA) and HBV DNA levels were measured by real-time PCR. 3-(4, 5-dimethylthiagol-2-yl)-2, 5-drphnyl tetrazolium bromide (MTT) assays were performed to evaluate cytotoxicity.
  
  
  RESULTS
  HBsAg and HBeAg expressions were reduced by various DNAzymes (0.1 - 2.5 micromol/L) with different substrate-recognition domains after transfection. The antiviral effects of DNAzymes were apparent until 72 h post-transfection. The inhibition rates of the DNAzymes at the same dose on HBsAg and HBeAg in the same period of post-transfection were as the following: DrzBS-9 > DrzBS-8 > DrzBS-7; DrzBC-9 > DrzBC-8 > DrzBC-7. Among all the DNAzymes used, DrzBS-9 targeting S gene and DrzBC-9 targeting C gene were most potent, with HBsAg and HBeAg reduced 95% and 92% 48 h post-transfection at the dose of 2.5 micromol/L, respectively. The inhibition effects on HBV DNA by various DNAzymes with different substrate-recognition domains were of no significance. There were no evident cytotoxic effects of these DNAzymes in the range from 0.1 to 2.5 micromol/L.
  
  
  CONCLUSIONS
  10-23 DNAzymes with different substrate-recognition domains targeting HBV S gene and C gene mRNA possessed specific inhibition effects in 2.2.15 cells, and DrzBS-9 targeting S gene and DrzBC-9 targeting C gene were most potent.
authors.affiliation: Institute of Infectious Diseases, First Affiliated Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310003, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Hou
authors.forename: Jian-er
authors.initials: JE
authors.lastname: Wo
authors.forename: Ke-zhou
authors.initials: KZ
authors.lastname: Liu
authors.forename: Min-wei
authors.initials: MW
authors.lastname: Li
authors.forename: Li-wei
authors.initials: LW
authors.lastname: Chen
authors.forename: Zhong-rong
authors.initials: ZR
authors.lastname: Hu
authors.forename: Rong-hua
authors.initials: RH
authors.lastname: Liu
authors.forename: Min-jun
authors.initials: MJ
authors.lastname: Hu
mesh_terms: D002460:Cell Line; D021881:DNA, Catalytic / Q000494:pharmacology*; D004279:DNA, Viral / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D015967:Gene Expression Regulation, Viral / Q000187:drug effects*; D005814:Genes, Viral; D006514:Hepatitis B Surface Antigens / Q000032:analysis; D006513:Hepatitis B e Antigens / Q000032:analysis; D006515:Hepatitis B virus / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D016133:Polymerase Chain Reaction; D014162:Transfection
chemical_list: D021881:DNA, Catalytic; D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens