title: Cellular pathway of plasmids vectorized by cholesterol-based cationic liposomes.
abstract: We investigated by transmission electron microscopy the cellular route in tumor MCF7 cells of DNA labeled with digoxigenin, carried by cationic liposomes (Lip+) prepared from TMAEC-Chol [3 beta(N-(N',N',N'-trimethylaminoethane)-carbamoyl)cholesterol iodide] and TEAPC-Chol [3 beta(N-(N',N',N'-triethylaminopropane)-carbamoyl)cholesterol iodide], two cholesterol-based cationic lipids containing a quaternary ammonium. In a previous work we showed the pathway of cationic lipid/plasmid complexes from the beginning of endocytosis until their entry into the perinuclear area. Beyond this limit, unlabeled exogenous plasmids cannot be distinguished with nuclear DNA. This work dealt with the cellular fate of cationic liposome-vectorized plasmids labeled with digoxigenin using an immunogold procedure. Early after the beginning of transfection (30 min, 1 hr, 5 hr), gold particles were observed only in the cytoplasm and in endosome-like vesicles, whereas after 24 hr gold particles were densely present in the nucleus. These results demonstrate the nuclear localization of plasmids vectorized by the cationic liposomes used. The results are discussed in comparison with transfection efficiency measurements.
authors.affiliation: Laboratoire de Chimie Structurale et Spectroscopie Biomoléculaire, CNRS UPRES-A 7031, UFR SMBH (Santé, Médecine et Biologie Humaine), Université Paris XIII, Bobigny, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Briane
authors.forename: Denis
authors.initials: D
authors.lastname: Lesage
authors.forename: An
authors.initials: A
authors.lastname: Cao
authors.forename: Robert
authors.initials: R
authors.lastname: Coudert
authors.forename: Nicole
authors.initials: N
authors.lastname: Lievre
authors.forename: Jean Loup
authors.initials: JL
authors.lastname: Salzmann
authors.forename: Eliane
authors.initials: E
authors.lastname: Taillandier
mesh_terms: D002412:Cations; D002467:Cell Nucleus / Q000378:metabolism / Q000648:ultrastructure; D002784:Cholesterol / Q000031:analogs & derivatives / Q000737:chemistry; D004076:Digoxigenin; D004705:Endocytosis; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D006801:Humans; D007150:Immunohistochemistry; D008081:Liposomes / Q000737:chemistry; D014162:Transfection; D014407:Tumor Cells, Cultured; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
chemical_list: C459406:3beta(N-(N',N',N'-triethylaminopropane)carbamoyl)cholesterol iodide; C459405:3beta(N-(N',N',N'-trimethylaminoethane)carbamoyl)cholesterol iodide; D002412:Cations; D008081:Liposomes; D002784:Cholesterol; D001616:beta-Galactosidase; D004076:Digoxigenin