title: In vivo reprogramming of hTERT by trans-splicing ribozyme to target tumor cells.
abstract: We have developed and validated a new tumor-targeting gene therapy strategy based upon the targeting and replacement of human telomerase reverse transcriptase (hTERT) RNA, using a trans-splicing ribozyme. By constructing novel adenoviral vectors harboring the hTERT-targeting trans-splicing ribozymes with the downstream reporter gene (Ad-Ribo-LacZ) or suicide gene (Ad-Ribo-HSVtk) driven by the cytomegalovirus (CMV) promoter, we demonstrated that this viral system selectively marks tumor cells expressing hTERT or sensitizes tumor cells to prodrug treatments. We confirmed that Ad-Ribo-LacZ successfully and selectively delivered a ribozyme that performed a highly specific trans-splicing reaction into hTERT-expressing cancer cells, both in vitro and in a peritoneal carcinomatosis nude mouse model. We also determined that the hTERT-specific expression of the suicide gene in the Ad-Ribo-HSVtk, and treatment with the corresponding prodrug, reduced tumor progression with almost the same efficacy as the strong constitutive CMV promoter-driven adenovirus, both in cancer cell lines and in nude mouse HT-29 xenografts. These observations provide the basis for a novel approach to cancer gene therapy, and demonstrate that trans-splicing ribozymes can be employed as targeting anti-cancer agents which recognize cancer-specific transcripts and reprogram them, thereby combating cancerous cells.
authors: Research Institute & Hospital, National Cancer Center, Goyang, South Korea.
authors: Seung-Hee
authors: SH
authors: Hong
authors: Jin-Sook
authors: JS
authors: Jeong
authors: Yoon-Jong
authors: YJ
authors: Lee
authors: Haeng-Im
authors: HI
authors: Jung
authors: Kyoung-Sook
authors: KS
authors: Cho
authors: Chang-Min
authors: CM
authors: Kim
authors: Byung-Su
authors: BS
authors: Kwon
authors: Bruce A
authors: BA
authors: Sullenger
authors: Seong-Wook
authors: SW
authors: Lee
authors: In-Hoo
authors: IH
authors: Kim
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D002461:Cell Line, Transformed; D045744:Cell Line, Tumor; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology; D018390:Gene Targeting; D005822:Genetic Vectors / Q000008:administration & dosage; D019073:HT29 Cells; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D010534:Peritoneal Neoplasms / Q000201:enzymology / Q000235:genetics / Q000628:therapy; D016337:RNA, Catalytic / Q000235:genetics* / Q000378:metabolism*; D019098:Telomerase / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*; D020040:Trans-Splicing / Q000235:genetics*; D019076:Transgenes
chemical_list: D016337:RNA, Catalytic; C509186:TERT protein, human; D019098:Telomerase