title: RNAi-mediated gene knockdown and anti-angiogenic therapy of RCCs using a cyclic RGD-modified liposomal-siRNA system.
abstract: Angiogenesis is one of crucial processes associated with tumor growth and development, and consequently a prime target for cancer therapy. Although tumor endothelial cells (TECs) play a key role in pathological angiogenesis, investigating phenotypical changes in neovessels when a gene expression in TEC is suppressed is a difficult task. Small interfering RNA (siRNA) represents a potential agent due to its ability to silence a gene of interest. We previously developed a system for in vivo siRNA delivery to cancer cells that involves a liposomal-delivery system, a MEND that contains a unique pH-sensitive cationic lipid, YSK05 (YSK-MEND). In the present study, we report on the development of a system that permits the delivery of siRNA to TECs by combining the YSK-MEND and a ligand that is specific to TECs. Cyclo(Arg-Gly-Asp-D-Phe-Lys) (cRGD) is a well-known ligand to αVβ3 integrin, which is selectively expressed at high levels in TECs. We incorporated cRGD into the YSK-MEND (RGD-MEND) to achieve an efficient gene silencing in TECs. Quantitative RT-PCR and the 5' rapid amplification of cDNA ends PCR indicated that the intravenous injection of RGD-MEND at a dose of 4.0mg/kg induced a significant RNAi-mediated gene reduction in TEC but not in endothelial cells of other organs. Finally, we evaluated the therapeutic potency of the RGD-MEND encapsulating siRNA against vascular endothelial growth factor receptor 2. A substantial delay in tumor growth was observed after three sequential RGD-MEND injections on alternate days. In conclusion, the RGD-MEND represents a new approach for the characterization of TECs and for us in anti-angiogenic therapy.
authors.affiliation: Laboratory of Innovative Nanomedicine, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo 060-0812, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Sakurai
authors.affiliation: Laboratory of Innovative Nanomedicine, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo 060-0812, Japan.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Hatakeyama
authors.affiliation: Laboratory of Innovative Nanomedicine, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo 060-0812, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Laboratory of Innovative Nanomedicine, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo 060-0812, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Hyodo
authors.affiliation: Laboratory of Innovative Nanomedicine, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo 060-0812, Japan.
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Akita
authors.affiliation: Division of Vascular Biology, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo 060-0812, Japan.
authors.forename: Noritaka
authors.initials: N
authors.lastname: Ohga
authors.affiliation: Division of Vascular Biology, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo 060-0812, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Hida
authors.affiliation: Laboratory of Innovative Nanomedicine, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo 060-0812, Japan. Electronic address: harasima@pharm.hokudai.ac.jp.
authors.forename: Hideyoshi
authors.initials: H
authors.lastname: Harashima
mesh_terms: D000818:Animals; D016503:Drug Delivery Systems; D057809:HEK293 Cells; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry* / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009369:Neoplasms / Q000098:blood supply / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D009389:Neovascularization, Pathologic / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D010456:Peptides, Cyclic / Q000737:chemistry* / Q000378:metabolism; D010880:Piperidines / Q000737:chemistry / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000235:genetics / Q000627:therapeutic use; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics*
chemical_list: D008055:Lipids; D008081:Liposomes; D010456:Peptides, Cyclic; D010880:Piperidines; D034741:RNA, Small Interfering; C580570:YSK05; C507169:cyclic arginine-glycine-aspartic acid peptide; D040301:Vascular Endothelial Growth Factor Receptor-2
keywords: Active targeting; Anti-angiogenic therapy; Cyclic RGD; Liposome; siRNA