title: Folate-linked lipid-based nanoparticles for synthetic siRNA delivery in KB tumor xenografts.
abstract: RNA interference (RNAi) is a sequence-specific gene-silencing mechanism triggered by synthetic small interfering RNA (siRNA), and is utilized in a wide range of fields including cancer gene therapy by down-regulating a specific target protein. In this study, for tumor-targeted siRNA delivery, we developed a folate-linked nanoparticle (NP-F), and evaluated the potential of NP-F-mediated tumor gene therapy in human nasopharyngeal KB cells, which overexpressed folate receptor (FR). NP-F was composed of cholesteryl-3beta-carboxyamidoethylene-N-hydroxyethylamine (OH-Chol), Tween 80 and folate-poly(ethylene glycol)-distearoylphosphatidylethanolamine conjugate (f-PEG(2000)-DSPE), and NP-P was substituted f-PEG(2000)-DSPE in NP-F PEG(2000)-DSPE for a non-targeting nanoparticle. The NP-F and siRNA complex (nanoplex) formed at a charge ratio (+/-) of 2/1 in the presence of 5mM NaCl was injectable size and increased transfection efficiency in the cells. NP-F showed a significantly higher intracellular amount of siRNA and stronger localization of siRNA in the cytoplasm than NP-P. When Her-2 siRNA was transfected into cells by NP-F and NP-P, NP-F significantly inhibited tumor growth, and selectively suppressed Her-2 protein expression more than NP-P. In in vivo gene therapy, a NP-F nanoplex of Her-2 siRNA by intratumoral injection significantly inhibited tumor growth of KB xenografts compared with control siRNA, but a NP-P nanoplex did not. These results of the experiments have provided optimal conditions to form folate-linked nanoparticle complexes with siRNA for folate-targeted gene therapy.
authors.affiliation: Institute of Medicinal Chemistry, Hoshi University, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshizawa
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Hattori
authors.forename: Motoki
authors.initials: M
authors.lastname: Hakoshima
authors.forename: Kimiko
authors.initials: K
authors.lastname: Koga
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Maitani
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002352:Carrier Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D024202:Electrophoretic Mobility Shift Assay; D058973:Folate Receptors, GPI-Anchored; D005492:Folic Acid / Q000737:chemistry / Q000378:metabolism*; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D008055:Lipids / Q000737:chemistry*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D053758:Nanoparticles; D009303:Nasopharyngeal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000737:chemistry / Q000378:metabolism*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D013997:Time Factors; D014162:Transfection; D023041:Xenograft Model Antitumor Assays
chemical_list: D002352:Carrier Proteins; D058973:Folate Receptors, GPI-Anchored; D005492:Folic Acid; D008055:Lipids; D034741:RNA, Small Interfering; D018719:Erb-b2 Receptor Tyrosine Kinases; D011956:Receptors, Cell Surface; C508053:ERBB2 protein, human