Generation of a ribozyme-adenoviral vector against K-ras mutant human lung cancer cells.
ras mutations represent one of the most common oncogenetic lesions in human non-small cell lung cancer (NSCLC) and adversely affect the survival of patients afflicted with this disease. ras-directed gene therapy in the past employed primarily antisense oligonucleotides (AS-ODN) or expression vectors (such as a viral vector construct) that deliver the antisense sequence to inactivate the mutant oncogene message. These approaches produced minimal toxicity, and yet were limited in efficacy. Ribozymes present a viable alternative in antisense therapy by virtue of their renewable catalytic capability for site-specific RNA cleavage. We recently produced an adenoviral vector with a hammerhead ribozyme transgene (KRbz) that is specific for the K-ras codon 12 mutant sequence GUU, given the considerations that (a) in the United States, approx 30% of human NSCLCs express K-ras oncogene mutations, nearly all of which reside in codon 12; (b) anti-K-ras, anti-H, as well as anti-N-ras hammerhead ribozymes are potent growth inhibitors in various human cancers tested; and (c) in vitro and animal model studies suggest that ribozymes directed at oncogene (K- and H-ras C-fos, BCR-ABL) or human immunodeficiency viral gene messages are more effective than their antisense counterpart. This article describes the techniques involved in the production of the KRbz-adenoviral vector that is specific for the K-ras mutation GTT, and summarizes its in vivo antitumor effect against NSCLC xenografts expressing the relevant K-ras mutation in athymic mice.
Baylor-Sammons Cancer Center, Baylor University Medical Center, Dallas, TX 75246, USA.
Y A
YA
Zhang
J
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Nemunaitis
A W
AW
Tong
D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics*; D002460:Cell Line; D004252:DNA Mutational Analysis / Q000379:methods; D005229:Fatty Acids, Monounsaturated / Q000737:chemistry; D011905:Genes, ras; D005821:Genetic Techniques; D005822:Genetic Vectors / Q000235:genetics*; D006801:Humans; D008081:Liposomes; D008175:Lung Neoplasms / Q000235:genetics*; D009154:Mutation; D010957:Plasmids; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D016337:RNA, Catalytic / Q000235:genetics*; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D014162:Transfection / Q000379:methods
D005229:Fatty Acids, Monounsaturated; D008081:Liposomes; D000644:Quaternary Ammonium Compounds; D016337:RNA, Catalytic; C070046:1,2-dioleoyloxy-3-(trimethylammonium)propane