In vivo electroporetic transfer of bcl-2 antisense oligonucleotide inhibits the development of hepatocellular carcinoma in rats.
To investigate the potential use of a bcl-2 antisense oligonucleotide for therapy against hepatocellular carcinoma, we examined the effects of the electroporetic transfer of a bcl-2 antisense oligonucleotide on rat hepatocarcinogenesis induced by N-nitrosomorpholine (NNM). Sprague-Dawley rats were given water containing 175 mg/l NNM for 8 weeks and received intraperitoneal injections of a bcl-2 antisense phosphorothioate oligonucleotide, a sense oligonucleotide or a scrambled sequence oligonucleotide encapsulated in empty liposomes, at a dose of 150 microg oligonucleotide/kg body weight, every 4 weeks. One hour after injection, in vivo electroporation was performed on the liver to achieve selective transfer of the oligonucleotides. By week 16, the rats that had received the bcl-2 antisense oligonucleotide had significantly fewer and smaller precancerous liver lesions positive for glutathione-S-transferase (placental type), and a significantly lower incidence of hepatocellular carcinoma in the electroporation zone than rats that had received the sense or the scrambled oligonucleotides. Moreover, the bcl-2 antisense oligonucleotide significantly increased the apoptotic indices in foci, neoplastic nodules and in hepatocellular carcinomas. The expression of bcl-2 mRNA also decreased, and 3'-fragments of bcl-2mRNA produced by cleavage at the antisense target site were detected in rat liver. Mean cellular fluorescence in the liver increased with higher doses of fluorescein-isothiocyanate-labeled antisense or sense oligonucleotides. Our results show that the electroporetic transfer of bcl-2 antisense oligonucleotide can inhibit rat hepatocarcinogenesis.
Baba
M
M
Department of Gastrointestinal Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
Iishi
H
H
Tatsuta
M
M
D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D015152:Blotting, Northern; D002273:Carcinogens; D006528:Carcinoma, Hepatocellular / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D004337:Drug Carriers; D016503:Drug Delivery Systems; D008081:Liposomes; D008113:Liver Neoplasms / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D009602:Nitrosamines; D016376:Oligonucleotides, Antisense / Q000627:therapeutic use*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000037:antagonists & inhibitors* / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley
D000970:Antineoplastic Agents; D002273:Carcinogens; D004337:Drug Carriers; D008081:Liposomes; D009602:Nitrosamines; D016376:Oligonucleotides, Antisense; D019253:Proto-Oncogene Proteins c-bcl-2; C002741:N-nitrosomorpholine