In vivo reprogramming of hTERT by trans-splicing ribozyme to target tumor cells.
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.
Hong
Seung-Hee
SH
Research Institute & Hospital, National Cancer Center, Goyang, South Korea.
Jeong
Jin-Sook
JS
Lee
Yoon-Jong
YJ
Jung
Haeng-Im
HI
Cho
Kyoung-Sook
KS
Kim
Chang-Min
CM
Kwon
Byung-Su
BS
Sullenger
Bruce A
BA
Lee
Seong-Wook
SW
Kim
In-Hoo
IH
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
D016337:RNA, Catalytic; C509186:TERT protein, human; D019098:Telomerase