1-2-dioleoyloxy-3-(trimethylammonium)propane and Chemical-and-Drug-Induced-Liver-Injury

Vectors for gene expression are the essential tools for both gene therapy and basic research. There are two groups of gene therapy vectors, viral and non-viral vectors. At present, toxicity triggered by vectors is one of the major concerns for clinical trials. In general, non-viral vectors, such as plasmid DNA-cationic liposome complex (lipoplex), are thought to be safer than viral vectors, such as adenovirus (Ad) vector, although lipoplex is less efficient in term of gene expression than the Ad vector. However, there has been no study directly comparing the gene expression efficiency and safety of viral and non-viral vectors. Here, we present evidence that the Ad vector shows much more efficient gene expression and is safer than lipoplex, at least with respect to the innate immune response. After being systemically administered to mice, the Ad vector showed a transduction efficiency that was 2 to 5 log orders higher than that of lipoplex, depending on the organ. On the other hand, surprisingly, the administration of lipoplex produced a greater amount of inflammatory cytokines such as interleukin-6, interleukin-12, and tumor necrosis factor-alpha than did the administration of the Ad vector, whereas a comparable level of hepatotoxicity was induced by these vectors. The production of inflammatory cytokines induced by the injection of lipoplex was reduced when the CpG motifs were removed completely from plasmid DNA. Thus, care should be taken to ensure the innate immune response induced by gene therapy vectors, especially lipoplex.

Topics: Adenoviridae; Animals; Chemical and Drug Induced Liver Injury; Cytokines; Drug Carriers; Excipients; Fatty Acids, Monounsaturated; Female; Gene Expression; Genetic Vectors; Immunity, Innate; Interleukin-12; Interleukin-6; Liposomes; Liver; Mice; Mice, Inbred C57BL; Paraffin Embedding; Plasmids; Quaternary Ammonium Compounds; Transduction, Genetic; Tumor Necrosis Factor-alpha

The purpose of this study was to investigate whether all-trans retinoic acid (ATRA), an active metabolite of retinal, incorporated in cationic liposomes composed of 1,2 dioleoyl-3-trimethylammonium propane (DOTAP)/cholesterol could inhibit established metastatic lung tumors by delivery to the pulmonary tumor site after intravenous injection. After intravenous injection in mice, the highest lung accumulation of [(3)H]ATRA was observed by the DOTAP/cholesterol liposomes formulation, while other formulations including [(3)H]ATRA dissolved in serum or [(3)H]ATRA incorporated in distearoyl-l-phosphatidylcholine (DSPC)/cholesterol liposomes produced little accumulation in the lung. In mice used as a model of lung cancer metastasis, ATRA incorporated in DOTAP/cholesterol liposomes, injected intravenously, reduced the number of tumor nodules compared with free ATRA or ATRA incorporated in DSPC/cholesterol liposomes. These results suggest that ATRA incorporated in cationic liposomes would be an effective strategy for differentiation therapy of lung cancer metastasis.

Topics: Animals; Antineoplastic Agents; Cations; Cell Line, Tumor; Cell Transplantation; Chemical and Drug Induced Liver Injury; Chemical Phenomena; Chemistry, Physical; Colonic Neoplasms; Drug Carriers; Fatty Acids, Monounsaturated; Injections, Intravenous; Liposomes; Lung; Lung Neoplasms; Male; Mice; Neoplasm Transplantation; Quaternary Ammonium Compounds; Rats; Rats, Inbred F344; Solubility; Tissue Distribution; Tretinoin