title: A new cationic liposome for efficient gene delivery with serum into cultured human cells: a quantitative analysis using two independent fluorescent probes.
abstract: Cationic liposomes are useful to transfer genes into eukaryotic cells in vitro and in vivo. However, liposomes with good transfection efficiency are often cytotoxic, and also require serum-free conditions for optimal activity. In this report, we describe a new formulation of cationic liposome containing DC-6-14, O,O'-ditetradecanoyl-N-(alpha-trimethylammonioacetyl)diethan olamine chloride, dioleoylphosphatidylethanolamine and cholesterol for gene delivery into cultured human cells. This liposome, dispersed in 5% serum-containing growth medium, efficiently delivered a plasmid DNA for GFP (green fluorescent protein) into more than 80% of the cultured human cell hybrids derived from HeLa cells and normal fibroblasts. Flow cytometric analysis revealed that the efficiency of the GFP gene expression was 40-50% in a tumor-suppressed cell hybrid, while it was greatly reduced in the tumorigenic counterpart. The enhanced GFP expression in tumor-suppressed cell hybrids was quantitatively well correlated with a prolonged presence of the plasmid DNA, which had been labeled with another fluorescent probe, ethidium monoazide, within the cells. These results suggest that a newly developed cationic liposome is useful for gene delivery in serum-containing medium into human cells and the stability of the plasmid DNA inside the cell is a crucial step in this liposome-mediated gene expression. The mechanisms by which cationic liposome mediates gene transfer into eukaryotic cells are also discussed.
authors.affiliation: Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Serikawa
authors.forename: N
authors.initials: N
authors.lastname: Suzuki
authors.forename: H
authors.initials: H
authors.lastname: Kikuchi
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
authors.forename: T
authors.initials: T
authors.lastname: Kitagawa
mesh_terms: D002412:Cations; D003470:Culture Media; D004274:DNA, Recombinant / Q000008:administration & dosage / Q000235:genetics; D005434:Flow Cytometry; D005456:Fluorescent Dyes; D015870:Gene Expression; D018014:Gene Transfer Techniques; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D006822:Hybrid Cells; D008081:Liposomes / Q000737:chemistry*; D008164:Luminescent Proteins / Q000235:genetics; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D000644:Quaternary Ammonium Compounds; D014162:Transfection
chemical_list: D002412:Cations; D003470:Culture Media; D004274:DNA, Recombinant; D005456:Fluorescent Dyes; D008081:Liposomes; D008164:Luminescent Proteins; D000644:Quaternary Ammonium Compounds; D049452:Green Fluorescent Proteins