Transfer of bcl-xs plasmid is effective in preventing and inhibiting rat hepatocellular carcinoma induced by N-nitrosomorpholine

• Published in: Gene therapy Vol. 8; no. 15; pp. 1149 - 1156
• Main Authors: BABA, M, IISHI, H, TATSUTA, M
• Format: Journal Article
• Language: English
• Published: Basingstoke Nature Publishing Group 01.08.2001
• Subjects: Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Animals; Apoptosis; Applied cell therapy and gene therapy; Bcl-x protein; bcl-xs gene; Biological and medical sciences; Biotechnology; Blotting, Western - methods; Body weight; Carcinoma, Hepatocellular - metabolism; Carcinoma, Hepatocellular - therapy; Chloramphenicol; Chloramphenicol O-Acetyltransferase - genetics; Electrodes; Electroporation; Electroporation - methods; Fundamental and applied biological sciences. Psychology; Gene Expression; Gene therapy; Genetic Therapy - methods; Health. Pharmaceutical industry; Hepatocellular carcinoma; Hepatocytes; Industrial applications and implications. Economical aspects; Injections, Intralesional; Liposomes; Liver; Liver cancer; Liver Neoplasms, Experimental - metabolism; Liver Neoplasms, Experimental - therapy; Male; Medical sciences; mRNA; N-nitrosomorpholine; Nitrosamines; Nodules; Plasmids; Precancerous Conditions - metabolism; Precancerous Conditions - therapy; Proto-Oncogene Proteins c-bcl-2 - analysis; Proto-Oncogene Proteins c-bcl-2 - genetics; Rats; Rats, Sprague-Dawley; Reporter gene; RNA, Messenger - analysis; Transfusions. Complications. Transfusion reactions. Cell and gene therapy; Tumors; Animal model; Rat; Rodentia; Liposome; Hepatic disease; Hepatocellular carcinoma; Electroporation; Malignant tumor; Genetic transfer; Vertebrata; Mammalia; Gene therapy; Vector; Apoptosis
• ISSN: 0969-7128; 1476-5462
• DOI: 10.1038/sj.gt.3301504

To examine the effect of the bcl-xs gene on the sequence from hepatic precancerous lesions, foci and neoplastic nodules, to hepatocellular carcinomas, Sprague-Dawley rats were given water containing 175 mg/l N-nitrosomorpholine (NNM) for 8 weeks. At weeks 1, 4 and 7, the left lobe of the rat liver was exposed and injected with the bcl-xs plasmid (pCR3.1-rat bcl-xs cDNA) or pCR3.1 encapsulated in cationic empty liposomes each at a dose of 80 microg plasmid/kg body weight. One minute later, low-field-strength, long-duration electric pulses were applied to the left lobe using a pincette electrode with circular poles 1 cm in diameter. The in vivo electroporation procedure significantly increased the transfer of the reporter gene chloramphenicol acetyl transferase (CAT) plasmid via empty liposomes. Thus, CAT mRNA was expressed not only at the sites of electrode contact but at sites 0.5-1.0 cm away from the electrode, and expression also increased with increasing doses of plasmid, meaning that in vivo electroporation enabled the expression of plasmid DNA throughout an extensive area of the rat liver. By week 11, the neoplastic nodules were significantly fewer and smaller in the bcl-xs group than in the pCR3.1 group at the two sites, one with and the other without electrode contact. No hepatocellular carcinomas were found in the rats that had received the bcl-xs plasmid, whereas these tumors were observed in 30% of the rats given pCR3.1. Moreover, overexpression of the bcl-xs protein was detected, and apoptotic activity was significantly increased in the neoplastic nodules, foci and hepatocytes adjacent to the hepatic lesions. These results indicate that the bcl-xs plasmid inhibits the occurrence and growth of rat hepatocellular carcinoma and may thus be effective for the prevention and treatment of human liver tumors.