title: 2-5A antisense therapy directed against human telomerase RNA inhibits telomerase activity and induces apoptosis without telomere impairment in cervical cancer cells.
abstract: Human telomerase RNA (hTR), an important component of telomerase, is a possible target of telomerase-based cancer gene therapy. The present study was undertaken to assess the efficacy of antisense hTR therapy using newly developed 2-5A (5'-phosphorylated 2'-5'-linked oligoadenylate)-linked oligonucleotides against cervical cancer cells. ME180 and SiHa cells were treated with 2-5A-linked antisense hTR designed to complement the region of hTR between residues 76 and 94. The hTR expression, telomerase activity, cell viability, and apoptosis were then examined. The 2-5A anti-hTR effectively degraded hTR and inhibited telomerase activity. The 2-5A mutant anti-hTR and the anti-hTR without 2-5A were not capable of inhibiting telomerase activity. Inhibition of telomerase by 2-5A anti-hTR rapidly decreased cell viability only in telomerase-positive cells within 3-6 days after the treatment, when telomere length has not yet been shortened. This inhibition was associated with apoptosis, possibly through activation of caspase family members. These findings suggest that 2-5A-linked antisense-hTR therapy has a potent telomerase-inhibitory effect associated with a cytocidal effect from caspase-induced apoptosis, and may therefore be a potential tool in telomerase-based gene therapy against cervical cancers.
authors.affiliation: Department of Obstetrics and Gynecology, Kanazawa University, School of Medicine, 13-1, Takaramachi, Kanazawa, Ishikawa 920-8641, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Yatabe
authors.forename: Satoru
authors.initials: S
authors.lastname: Kyo
authors.forename: Seiji
authors.initials: S
authors.lastname: Kondo
authors.forename: Taro
authors.initials: T
authors.lastname: Kanaya
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Wang
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Maida
authors.forename: Masahiro
authors.initials: M
authors.lastname: Takakura
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Nakamura
authors.forename: Masaaki
authors.initials: M
authors.lastname: Tanaka
authors.forename: Masaki
authors.initials: M
authors.lastname: Inoue
mesh_terms: D017209:Apoptosis; D015139:Blotting, Southern; D002470:Cell Survival; D005260:Female; D005434:Flow Cytometry; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D009841:Oligonucleotides / Q000494:pharmacology; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D012313:RNA / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019098:Telomerase / Q000037:antagonists & inhibitors* / Q000235:genetics*; D016615:Telomere / Q000378:metabolism; D013997:Time Factors; D014162:Transfection; D014407:Tumor Cells, Cultured; D002583:Uterine Cervical Neoplasms / Q000235:genetics* / Q000628:therapy
chemical_list: D009841:Oligonucleotides; D016376:Oligonucleotides, Antisense; D012313:RNA; D019098:Telomerase