title: [Study on telomerase inhibition by ribozyme targeted to telomerase RNA component].
abstract: OBJECTIVE
  To evaluate the possibility of using ribozyme technology for telomerase inhibition and cancer therapy.
  
  
  METHODS
  A hammer head ribozyme (telomerase ribozyme, teloRZ) directed against the RNA component of human telomerase (hTR) was designed and synthesized to serve as a telomerase inhibitor. An in vitro transcription plasmid and a eukaryotic expression plasmid containing teloRZ gene were constructed. In vitro cleavage reaction was carried out by mixing the ribozyme RNA with DIG-labeled-hTR in different reaction conditions. Cleavage bands were detected by digoxin chemilumines- cent assay. The eukaryotic expression plasmid was inducted into HeLa cells by lipofectamine; the telomerase activities and bio-characteristics of HeLa cells were detected continuously.
  
  
  RESULTS
  teloRZ showed a specific cleavage activity against the telomerase RNA component used as template. The in vitro cleavage ratio reached about 60%. The telomerase activities of cells expressing teloRZ dropped to eight times; the doubling times became longer and apoptosis ratios became higher with increasing population doublings (PDS); at 19-20 PDS 95% cells showed apoptosis.
  
  
  CONCLUSIONS
  These findings support the potential use of this ribozyme against immortalized cancer cells.
authors.affiliation: Laboratory of Medical Molecular Biology, West China University of Medical Sciences, Chengdu, 610041 P. R. China. QuY@hotmail.com
authors.forename: Y
authors.initials: Y
authors.lastname: Qu
authors.forename: X
authors.initials: X
authors.lastname: OuYang
authors.forename: S
authors.initials: S
authors.lastname: Liu
authors.forename: X
authors.initials: X
authors.lastname: Peng
authors.forename: B
authors.initials: B
authors.lastname: Liu
mesh_terms: D017209:Apoptosis; D001483:Base Sequence; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D016337:RNA, Catalytic / Q000494:pharmacology*; D019098:Telomerase / Q000037:antagonists & inhibitors*
chemical_list: D016337:RNA, Catalytic; D019098:Telomerase