title: Direct cytosolic siRNA delivery by reconstituted high density lipoprotein for target-specific therapy of tumor angiogenesis.
abstract: We described here the mechanisms by which small interfering RNA (siRNA) molecules incorporated in reconstituted high density lipoprotein (rHDL) were efficiently transferred into the cytoplasm of cells to perform target-specific therapy of tumor angiogenesis. Using fluorescent-tagged apolipoprotein A-I (apoA-I) and cholesterol-conjugated siRNA (Chol-siRNA), it was confirmed with FACS and confocal microscopic measurements that Chol-siRNA-loaded rHDL nanoparticles (rHDL/Chol-siRNA complexes) were successfully established and apoA-I certainly was attached to the surface of Chol-siRNA-loaded lipoplexes (Lipos/Chol-siRNA complexes). Stably assembled rHDL/Chol-siRNA complexes demonstrated proper nanosize, quasi-spherical shape and improved nuclease protection over naked Chol-siRNA. It was also interesting to note that rHDL provided a highly effective approach to transfer Chol-siRNA across the membrane directly into the cytoplasm via the scavenger receptor BI (SR-BI)-mediated non-endocytotic mechanism, thereby bypassing endo-lysosomal trapping. We also showed clear evidence that the in vitro implementation of rHDL for Chol-siRNA-VEGF (Chol-siRNA targeting vascular endothelial growth factor gene) delivery markedly promoted RNA interference (RNAi)-mediated degradation of VEGF mRNA, resulting in down-regulation of secreted VEGF protein. In vivo fluorescence imaging indicated that near-infrared (NIR) dye Cy5 labeled Chol-siRNA-loaded rHDL nanoparticles (rHDL/Cy5-Chol-siRNA complexes) displayed long circulation time, SR-BI positive tumor-selective targeting, and efficient cytosolic delivery capabilities. Furthermore, intravenous administration of Chol-siRNA-VEGF-loaded rHDL nanoparticles (rHDL/Chol-siRNA-VEGF complexes) significantly enhanced anti-tumor efficacy against breast cancer, decreased VEGF expression level, and inhibited formation of intratumoral microvessels at the tumor tissue. It was concluded that rHDL possessed therapeutic potential and versatility in mediating Chol-siRNA-VEGF direct cytosolic delivery for target-specific anti-angiogenic therapy in breast cancer.
authors.affiliation: State Key Laboratory of Natural Medicines, Department of Pharmaceutics, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Natural Medicines, Department of Pharmaceutics, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China.
authors.forename: Yazhe
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Natural Medicines, Department of Pharmaceutics, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China. Electronic address: zhoujp60@163.com.
authors.forename: Jianping
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Faculty of Pharmacy, University of Manitoba, 750 McDermot Avenue, Winnipeg, MB, Canada R3E 0T5.
authors.forename: Xiaochen
authors.initials: X
authors.lastname: Gu
authors.affiliation: State Key Laboratory of Natural Medicines, Department of Pharmaceutics, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China. Electronic address: wangcpu@163.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Natural Medicines, Department of Pharmaceutics, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China.
authors.forename: Congyan
authors.initials: C
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Natural Medicines, Department of Pharmaceutics, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Bao
authors.affiliation: State Key Laboratory of Natural Medicines, Department of Pharmaceutics, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Natural Medicines, Department of Pharmaceutics, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China.
authors.forename: Yuanru
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D020533:Angiogenesis Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D016632:Apolipoprotein A-I / Q000737:chemistry; D002784:Cholesterol / Q000737:chemistry* / Q000494:pharmacology; D003600:Cytosol / Q000187:drug effects* / Q000378:metabolism; D015536:Down-Regulation; D016503:Drug Delivery Systems / Q000379:methods*; D005260:Female; D006168:Guinea Pigs; D056945:Hep G2 Cells; D006801:Humans; D061986:MCF-7 Cells; D008297:Male; D051379:Mice; D008819:Mice, Nude; D053758:Nanoparticles / Q000737:chemistry; D009389:Neovascularization, Pathologic / Q000188:drug therapy*; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000737:chemistry* / Q000494:pharmacology; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays
chemical_list: D020533:Angiogenesis Inhibitors; D016632:Apolipoprotein A-I; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D042461:Vascular Endothelial Growth Factor A; D002784:Cholesterol
keywords: Anti-angiogenic therapy; Cholesterol-conjugated siRNA; Direct cytosolic delivery; Reconstituted high density lipoprotein; Tumor-selective accumulation; Vascular endothelial growth factor