title: Evidence for a specific intracellular localization of an antisense oligonucleotide in k562 cells.
abstract: In order to be active, antisense oligonucleotides (ASOs) should be delivered to the nuclei of cells. The lack of effect of some ASOs might be explained by poor distribution inside the cell. Here we describe the study of the intracellular distribution of an ASO in a leukemic cell line in which the ASO was not showing an effect. We used fluorescein isothiocyanate-labeled ASO and fluorescent or confocal microscopy. The internalised ASO was localized in a specific intracellular juxtanuclear region, showing no cytoplasmic or nuclear diffusion. Transfection of the ASO improved cellular distribution to the cytoplasm and nuclei and improved the ASO effect.
authors.affiliation: Institute of Molecular Pathology and Immunology, University of Porto, Portugal.
authors.forename: M Helena
authors.initials: MH
authors.lastname: Vasconcelos
authors.forename: Luis F
authors.initials: LF
authors.lastname: Maia
authors.forename: Cristina
authors.initials: C
authors.lastname: Sousa
authors.forename: Sandra S
authors.initials: SS
authors.lastname: Beleza
authors.forename: José E
authors.initials: JE
authors.lastname: Guimarães
mesh_terms: D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D004337:Drug Carriers; D005434:Flow Cytometry; D006801:Humans; D066298:In Vitro Techniques; D020014:K562 Cells / Q000378:metabolism*; D008081:Liposomes; D018613:Microscopy, Confocal; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000378:metabolism*; D010714:Phosphatidylethanolamines; D012333:RNA, Messenger / Q000378:metabolism; D011990:Receptors, Transferrin / Q000235:genetics / Q000378:metabolism
chemical_list: D015703:Antigens, CD; C068126:CD71 antigen; D004337:Drug Carriers; D008081:Liposomes; D016376:Oligonucleotides, Antisense; D010714:Phosphatidylethanolamines; D012333:RNA, Messenger; D011990:Receptors, Transferrin; C020888:1,2-dielaidoylphosphatidylethanolamine