Rapid inhibition of cancer cell growth induced by lentiviral delivery and expression of mutant-template telomerase RNA and anti-telomerase short-interfering RNA

• Published in: Cancer research (Chicago, Ill.) Vol. 64; no. 14; pp. 4833 - 4840
• Main Authors: SHANG LI, ROSENBERG, Jonathan E, DONJACOUR, Annemarie A, BOTCHKINA, Inna L, YUN KIT HOM, CUNHA, Gerald R, BLACKBURN, Elizabeth H
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA American Association for Cancer Research 15-07-2004
• Subjects: Animals; Antineoplastic agents; Apoptosis - genetics; Biological and medical sciences; Cell Division - genetics; Genetic Therapy - methods; Humans; Lentivirus; Lentivirus - genetics; Male; Medical sciences; Mice; Mice, Nude; Pharmacology. Drug treatments; Rats; RNA - biosynthesis; RNA - genetics; RNA, Small Interfering - biosynthesis; RNA, Small Interfering - genetics; Telomerase - biosynthesis; Telomerase - genetics; Telomere - genetics; Tumors; Urinary Bladder Neoplasms - blood supply; Urinary Bladder Neoplasms - genetics; Urinary Bladder Neoplasms - metabolism; Urinary Bladder Neoplasms - therapy; Xenograft Model Antitumor Assays; Virus; Cell proliferation; Delivery system; RNA; Enzyme; Retroviridae; Inhibitor; Mutation; Malignant tumor; Gene expression; Lentivirus; Telomerase
• ISSN: 0008-5472; 1538-7445
• DOI: 10.1158/0008-5472.can-04-0953

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.