title: Hammerhead ribozymes to modulate telomerase activity of endometrial carcinoma cells.
abstract: Telomerase is an excellent target molecule for cancer therapy, though any effective agents have never been developed in human subjects. We designed a variety of hammerhead ribozymes against human telomerase RNA (hTR) and hTERT mRNA and studied their possibility as a tool for cancer therapy. To search promising target site of hTR, the catalytic actiuity of 3 kinds of hammerhead ribozymes was studied in cell-free system. They showed equivalent catalytic activity, but only 36-ribozyme, which was designed to cleave the template region of hTR, revealed telomerase inhibitory activity in an endometrial carcinoma cell line. Among hTERT-mRNA-targeted ribozymes, the ribozyme to cleave 13 nucleotides downstream from the 5'-end of hTERT mRNA (13-ribozyme) exhibited the strongest telomerase-inhibitory activity, and the ribozyme to cleave 59 nucleotides upstream from the poly(A) tail showed clear activity. Stable transfection studies confirmed that the 36-ribozyme as well as the 13-ribozyme suppressed telomerase. These observations suggest that the template region of hTR and 5'end of hTERT mRNA are promising target sites for ribozymes to reduce telomerase activity.
authors.affiliation: Department of Obstetrics and Gynecology, Gifu University. yokoyama@cc.gifu-u.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Yokoyama
authors.forename: X
authors.initials: X
authors.lastname: Wan
authors.forename: A
authors.initials: A
authors.lastname: Shinohara
authors.forename: Y
authors.initials: Y
authors.lastname: Takahashi
authors.forename: T
authors.initials: T
authors.lastname: Tamaya
mesh_terms: D020121:5' Untranslated Regions / Q000235:genetics / Q000378:metabolism; D002384:Catalysis; D016889:Endometrial Neoplasms / Q000201:enzymology* / Q000628:therapy*; D005260:Female; D018390:Gene Targeting; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors; D006801:Humans; D012313:RNA; D016337:RNA, Catalytic; D019098:Telomerase / Q000037:antagonists & inhibitors* / Q000235:genetics* / Q000378:metabolism; D014161:Transduction, Genetic; D014407:Tumor Cells, Cultured
chemical_list: D020121:5' Untranslated Regions; D016337:RNA, Catalytic; C427204:hammerhead ribozyme; C422952:telomerase RNA; D012313:RNA; D019098:Telomerase