title: Rapid inhibition of cancer cell growth induced by lentiviral delivery and expression of mutant-template telomerase RNA and anti-telomerase short-interfering RNA.
abstract: In human cancers, telomeres are commonly maintained by elevated levels of the ribonucleoprotein enzyme telomerase, which contains an intrinsic templating RNA moiety (human telomerase RNA; hTER) and the core protein (human telomerase reverse transcriptase). We developed a lentiviral system for efficient overexpression of mutant-template human telomerase RNA (MT-hTer) to add mutant DNA to telomeres in cancer cells. We show that such MT-hTer overexpression rapidly inhibits cell growth and induces apoptosis in telomerase-positive precancerous or cancer cells but not in telomerase-negative cells. These rapid effects occurred independent of wild-type p53 and telomere length. Tumor growth and progression were significantly decreased in xenografts of human tumor cells overexpressing MT-hTers. Expression of a hairpin short-interfering RNA that specifically targeted the endogenous wild-type hTER template region, but spared the MT-hTers, also caused p53-independent cell growth inhibition and apoptosis, and when coexpressed with MT-hTer, synergistically killed cancer cells. Hence, anti-wild-type-hTER short-interfering RNA and MT-hTers may act through distinct pathways and, particularly in combination, represent a promising approach to anticancer therapies.
authors.affiliation: Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA 94143, USA.
authors.forename: Shang
authors.initials: S
authors.lastname: Li
authors.forename: Jonathan E
authors.initials: JE
authors.lastname: Rosenberg
authors.forename: Annemarie A
authors.initials: AA
authors.lastname: Donjacour
authors.forename: Inna L
authors.initials: IL
authors.lastname: Botchkina
authors.forename: Yun Kit
authors.initials: YK
authors.lastname: Hom
authors.forename: Gerald R
authors.initials: GR
authors.lastname: Cunha
authors.forename: Elizabeth H
authors.initials: EH
authors.lastname: Blackburn
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics; D002455:Cell Division / Q000235:genetics; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D008297:Male; D051379:Mice; D008819:Mice, Nude; D012313:RNA / Q000096:biosynthesis / Q000235:genetics*; D034741:RNA, Small Interfering / Q000096:biosynthesis / Q000235:genetics*; D051381:Rats; D019098:Telomerase / Q000096:biosynthesis / Q000235:genetics*; D016615:Telomere / Q000235:genetics; D001749:Urinary Bladder Neoplasms / Q000098:blood supply / Q000235:genetics / Q000378:metabolism / Q000628:therapy; D023041:Xenograft Model Antitumor Assays
chemical_list: D034741:RNA, Small Interfering; D012313:RNA; D019098:Telomerase