451
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O’Mahony AM, Desgranges S, Ogier J, Quinlan A, Devocelle M, Darcy R, Cryan JF, O’Driscoll CM. In Vitro Investigations of the Efficacy of Cyclodextrin-siRNA Complexes Modified with Lipid-PEG-Octaarginine: Towards a Formulation Strategy for Non-viral Neuronal siRNA Delivery. Pharm Res 2012. [DOI: 10.1007/s11095-012-0945-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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452
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Transcription Factors and Gene Expression. Mol Pharmacol 2012. [DOI: 10.1002/9781118451908.ch8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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453
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Bian Z, Xiao A, Cao M, Liu M, Liu S, Jiao Y, Yan W, Qi Z, Zheng Z. Anti-HBV efficacy of combined siRNAs targeting viral gene and heat shock cognate 70. Virol J 2012; 9:275. [PMID: 23158906 PMCID: PMC3534549 DOI: 10.1186/1743-422x-9-275] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 11/12/2012] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Hepatitis B virus (HBV) infection is a major health concern with more than two billion individuals currently infected worldwide. Because of the limited effectiveness of existing vaccines and drugs, development of novel antiviral strategies is urgently needed. Heat stress cognate 70 (Hsc70) is an ATP-binding protein of the heat stress protein 70 family. Hsc70 has been found to be required for HBV DNA replication. Here we report, for the first time, that combined siRNAs targeting viral gene and siHsc70 are highly effective in suppressing ongoing HBV expression and replication. METHODS We constructed two plasmids (S1 and S2) expressing short hairpin RNAs (shRNAs) targeting surface open reading frame of HBV(HBVS) and one plasmid expressing shRNA targeting Hsc70 (siHsc70), and we used the EGFP-specific siRNA plasmid (siEGFP) as we had previously described. First, we evaluated the gene-silencing efficacy of both shRNAs using an enhanced green fluorescent protein (EGFP) reporter system and flow cytometry in HEK293 and T98G cells. Then, the antiviral potencies of HBV-specific siRNA (siHBV) in combination with siHsc70 in HepG2.2.15 cells were investigated. Moreover, type I IFN and TNF-α induction were measured by quantitative real-time PCR and ELISA. RESULTS Cotransfection of either S1 or S2 with an EGFP plasmid produced an 80%-90% reduction in EGFP signal relative to the control. This combinational RNAi effectively and specifically inhibited HBV protein, mRNA and HBV DNA, resulting in up to a 3.36 log10 reduction in HBV load in the HepG2.2.15 cell culture supernatants. The combined siRNAs were more potent than siHBV or siHsc70 used separately, and this approach can enhance potency in suppressing ongoing viral gene expression and replication in HepG2.2.15 cells while forestalling escape by mutant HBV. The antiviral synergy of siHBV used in combination with siHsc70 produced no cytotoxicity and induced no production of IFN-α, IFN-β and TNF-α in transfected cells. CONCLUSIONS Our combinational RNAi was sequence-specific, effective against wild-type and mutant drug-resistant HBV strains, without triggering interferon response or producing any side effects. These findings indicate that combinational RNAi has tremendous promise for developing innovative therapy against viral infection.
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Affiliation(s)
- Zhongqi Bian
- Center for Infectious Diseases, Kunming General Hospital, PLA, 212 Daguan Rd, Kunming 650032, PR China.
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454
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Ayub M, Bayley H. Individual RNA base recognition in immobilized oligonucleotides using a protein nanopore. NANO LETTERS 2012; 12:5637-43. [PMID: 23043363 PMCID: PMC3505278 DOI: 10.1021/nl3027873] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Protein nanopores are under investigation as key components of rapid, low-cost platforms to sequence DNA molecules. Previously, it has been shown that the α-hemolysin (αHL) nanopore contains three recognition sites, capable of discriminating between individual DNA bases when oligonucleotides are immobilized within the nanopore. However, the direct sequencing of RNA is also of critical importance. Here, we achieve sharply defined current distributions that enable clear discrimination of the four nucleobases, guanine, cytosine, adenine, and uracil, in RNA. Further, the modified bases, inosine, N(6)-methyladenosine, and N(5)-methylcytosine, can be distinguished.
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455
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Gene Silencing Mediated by siRNA-binding Fusion Proteins Is Attenuated by Double-stranded RNA-binding Domain Structure. MOLECULAR THERAPY-NUCLEIC ACIDS 2012; 1:e53. [PMID: 23629028 PMCID: PMC3511671 DOI: 10.1038/mtna.2012.43] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Delivery of small interfering RNA (siRNA) targeted to specific cell types is a significant challenge for the development of RNA interference-based therapeutics. Recently, PTD-DRBD, a double-stranded RNA binding domain (DRBD) fused to the TAT protein transduction domain (PTD), was shown to be effective at delivering siRNA in a non-cell type-specific manner. Here, we evaluated the potential of DRBD as a general protein platform for targeted small interfering RNA (siRNA) delivery. We found that a single DRBD was insufficient to stably complex siRNA when fused to targeting peptides other than PTD, which facilitated nonspecific nucleic acid binding. In contrast to PTD-DRBD, fusion proteins containing two DRBDs (2× DRBD) yielded specific and stable siRNA binding. These proteins could mediate the cellular uptake of siRNA in vitro, though compared with PTD-DRBD gene silencing was attenuated by endosomal entrapment. Our findings suggest that unlike a single DRBD, 2× DRBD inhibits siRNA escape into the cytoplasm and/or induces an internalization pathway distinct from that of PTD-DRBD. Collectively, these data indicate that while 2× DRBD retains siRNA-binding activity when fused to different cell surface-interacting peptides, the utility of 2× DRBD for cell-specific RNA interference is limited without further protein engineering to enhance the bioavailability of the delivered siRNAs.
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456
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Abstract
Single-stranded RNAs interact with components of the RNA interference pathway to reduce the expression of target mRNAs. Now, Lima et al. and Yu et al. show that, with extensive chemical modifications, small single-stranded RNAs can robustly induce gene silencing with efficacy similar to their double-stranded counterparts.
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457
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Ibrišimović M, Kneidinger D, Lion T, Klein R. An adenoviral vector-based expression and delivery system for the inhibition of wild-type adenovirus replication by artificial microRNAs. Antiviral Res 2012; 97:10-23. [PMID: 23127366 PMCID: PMC3552158 DOI: 10.1016/j.antiviral.2012.10.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 10/17/2012] [Accepted: 10/25/2012] [Indexed: 11/28/2022]
Abstract
Human adenoviruses are rarely associated with life-threatening infections in healthy individuals. However, immunocompromised patients, and particularly allogeneic hematopoietic stem cell transplant recipients, are at high risk of developing disseminated and potentially fatal disease. The efficacy of commonly used drugs to treat adenovirus infections (i.e., cidofovir in most cases) is limited, and alternative treatment options are needed. Artificial microRNAs (amiRNAs) are a class of synthetic RNAs resembling cellular miRNAs, and, similar to their natural relatives, can mediate the knockdown of endogenous gene expression. This process, termed RNA interference, can be harnessed to target and potentially silence both cellular and viral genes. In this study, we designed amiRNAs directed against adenoviral E1A, DNA polymerase, and preterminal protein (pTP) mRNAs in order to inhibit adenoviral replication in vitro. For the expression of amiRNA-encoding sequences, we utilized replication-deficient adenoviral vectors. In cells transduced with the recombinant vectors and infected with the wild-type (wt) adenovirus, one particular amiRNA that was directed against the pTP mRNA was capable of decreasing the output of infectious wt virus progeny by 2.6 orders of magnitude. This inhibition rate could be achieved by concatemerizing amiRNA-encoding sequences to allow for high intracellular amiRNA concentrations. Because superinfecting wt virus induces the replication and amplification of the recombinant adenoviral vector, amiRNA concentrations were increased in cells infected with wt adenovirus. Furthermore, a combination of amiRNA expression and treatment of infected cells with cidofovir resulted in additive effects that manifested as a total reduction of infectious virus progeny by greater than 3 orders of magnitude.
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Affiliation(s)
- Mirza Ibrišimović
- Children's Cancer Research Institute, St. Anna Kinderkrebsforschung, Department of Pediatrics, Medical University of Vienna, Austria
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458
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Zhou J, Bobbin ML, Burnett JC, Rossi JJ. Current progress of RNA aptamer-based therapeutics. Front Genet 2012; 3:234. [PMID: 23130020 PMCID: PMC3486975 DOI: 10.3389/fgene.2012.00234] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 10/15/2012] [Indexed: 01/07/2023] Open
Abstract
Aptamers are single-stranded nucleic acids that specifically recognize and bind tightly to their cognate targets due to their stable three-dimensional structure. Nucleic acid aptamers have been developed for various applications, including diagnostics, molecular imaging, biomarker discovery, target validation, therapeutics, and drug delivery. Due to their high specificity and binding affinity, aptamers directly block or interrupt the functions of target proteins making them promising therapeutic agents for the treatment of human maladies. Additionally, aptamers that bind to cell surface proteins are well suited for the targeted delivery of other therapeutics, such as conjugated small interfering RNAs (siRNA) that induce RNA interference (RNAi). Thus, aptamer-siRNA chimeras may offer dual-functions, in which the aptamer inhibits a receptor function, while the siRNA internalizes into the cell to target a specific mRNA. This review focuses on the current progress and therapeutic potential of RNA aptamers, including the use of cell-internalizing aptamers as cell-type specific delivery vehicles for targeted RNAi. In particular, we discuss emerging aptamer-based therapeutics that provide unique clinical opportunities for the treatment various cancers and neurological diseases.
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Affiliation(s)
- Jiehua Zhou
- Division of Molecular and Cellular Biology, Beckman Research Institute of City of Hope Duarte, CA, USA
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459
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Guo B, Peng S, Liang C, He X, Xiao C, Lu C, Jiang M, Zhao H, Lu A, Zhang G. Recent developments in bone anabolic therapy for osteoporosis. Expert Rev Endocrinol Metab 2012; 7:677-685. [PMID: 30754125 DOI: 10.1586/eem.12.63] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Osteoporosis is a disorder in which there is a net bone loss and microarchitectural deterioration with an increased risk of bone fracture because of uncoupling of bone formation and bone resorption. The treatment of osteoporosis aims to inhibit bone resorption by osteoclasts and/or promote bone formation by osteoblasts. However, most of the current approaches for treating osteoporosis focus on inhibiting bone resorption. As the only US FDA-approved anabolic agent, the recombinant human parathyroid hormone is recommended for consecutive 2-year period treatment in a clinical setting. Therefore, it is highly desirable to identify novel bone anabolic agents or approaches for osteoporosis treatment. In this review, the authors introduce a new bone anabolic therapy by means of RNAi strategy. Specifically, the authors also discuss the current status and perspectives for RNAi as a novel anabolic approach in the treatment of osteoporosis.
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Affiliation(s)
- Baosheng Guo
- a Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong SAR, China
| | - Songlin Peng
- a Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong SAR, China
| | - Chao Liang
- a Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong SAR, China
| | - Xiaojuan He
- b Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Dongzhimen, Beijing 100700, China
| | - Cheng Xiao
- b Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Dongzhimen, Beijing 100700, China
| | - Cheng Lu
- b Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Dongzhimen, Beijing 100700, China
| | - Miao Jiang
- b Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Dongzhimen, Beijing 100700, China
| | - Hongyan Zhao
- b Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Dongzhimen, Beijing 100700, China
| | - Aiping Lu
- b Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Dongzhimen, Beijing 100700, China
| | - Ge Zhang
- c Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong SAR, China.
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460
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Abstract
Bombyx mori nucleopolyhedrovirus (BmNPV) that infects the silkworm, B. mori, accounts for >50% of silk cocoon crop losses globally. We speculated that simultaneous targeting of several BmNPV essential genes in transgenic silkworm would elicit a stable defense against the virus. We introduced into the silkworm germline the vectors carrying short sequences of four essential BmNPV genes in tandem, either in sense or antisense or in inverted-repeat arrangement. The transgenic silkworms carrying the inverted repeat-containing transgene showed stable protection against high doses of baculovirus infection. Further, the antiviral trait was incorporated to a commercially productive silkworm strain highly susceptible to BmNPV. This led to combining the high-yielding cocoon and silk traits of the parental commercial strain and a very high level of refractoriness (>75% survival rate as compared to <15% in nontransgenic lines) to baculovirus infection conferred by the transgene. We also observed impaired infectivity of the occlusion bodies derived from the transgenic lines as compared to the wild-type ones. Currently, large-scale exploitation of these transgenic lines is underway to bring about economic transformation of sericulture.
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461
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462
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Pereira DM, Rodrigues PM, Borralho PM, Rodrigues CMP. Delivering the promise of miRNA cancer therapeutics. Drug Discov Today 2012; 18:282-9. [PMID: 23064097 DOI: 10.1016/j.drudis.2012.10.002] [Citation(s) in RCA: 213] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 09/19/2012] [Accepted: 10/05/2012] [Indexed: 12/16/2022]
Abstract
MicroRNAs (miRNAs) are pivotal post-transcriptional gene expression regulators. These endogenous small non-coding RNAs aberrantly expressed in cancer have significant roles in tumorigenesis and progression. Currently, miRNAs are being pursued as diagnostic and prognostic biomarkers, and as therapeutic tools in cancer. miRNA modulation provides the unique ability to fine-tune multiple genes simultaneously, thereby regulating relevant signaling pathways involved in cell differentiation, proliferation and survival. This unique miRNA feature shifts the traditional one drug one target paradigm to a novel one drug multiple targets paradigm. We herein review in vivo strategies of miRNA modulator (mimic and/or inhibitor) delivery in cancer models, a subject that remains the key challenge to the establishment of this novel class of RNA therapeutics.
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Affiliation(s)
- Diane M Pereira
- Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon, Av. Prof. Gama Pinto, 1649-003 Lisbon, Portugal
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463
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Bakhshandeh B, Soleimani M, Hafizi M, Ghaemi N. A comparative study on nonviral genetic modifications in cord blood and bone marrow mesenchymal stem cells. Cytotechnology 2012; 64:523-40. [PMID: 22328133 PMCID: PMC3432529 DOI: 10.1007/s10616-012-9430-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 01/12/2012] [Indexed: 01/12/2023] Open
Abstract
The focus of both clinical and basic studies on stem cells is increasing due to their potentials in regenerative medicine and cell-based therapies. Recently stem cells have been genetically modified to enhance an existing character in or to bring a new property to them. However, accomplishment of declared goals requires detailed knowledge about their molecular characteristics which could be achieved by genetic modifications mostly through nonviral transfection strategies. Capable of differentiating into multiple cells, human unrestricted somatic stem cells (hUSSCs) and human mesenchymal stem cells (hMSCs) seem to be suitable candidates for transfection approaches. Involvement of microRNAs (miRNAs) in many biological processes makes their transfection evaluation valuable. Herein we investigated the efficacy and toxicity of four typically used transfection reagents (Arrest-In, Lipofectamine 2000, Oligofectamine and HiPerfect) systematically to deliver fluorescent labeled-miRNA and Green Fluorescent Protein (GFP) expressing plasmid into hUSSCs and hMSCs. The authenticity of stem cells was verified by differentiation experiments along with flow cytometry of surface markers. Our study revealed that stemness properties of these stem cells were not affected by transient transfection. Moreover the ratios of cell viability and transfection efficiency in both analyzed stem cells were reversed. Considering cell viability, the highest fraction of GFP-expressing cells was obtained using Oligofectamine (~50%) while the highest transfection rate of miRNA was achieved by Lipofectamine 2000 (~90%). Moreover dependency of hMSCs to size of transfected nucleic acid and time-dependency of Oligofectamine and their affection on the yield of transfection were observed. Cytotoxicity assessments also showed that hUSSCs are sensitive to HiPerFect. In addition cells treated by Lipofectamine showed morphological changes. Representing the efficient nucleic acid transfection, our research facilitates comprehensive genetic modification of stem cells and demonstrates powerful approaches to understand stem cell molecular regulation mechanisms, which eventually improves nonviral cell-mediated gene therapy.
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Affiliation(s)
- Behnaz Bakhshandeh
- Department of Biotechnology, College of Science, University of Tehran, Tehran, Iran
- Stem Cell Biology Department, Stem Cell Technology Research Center, Tehran, Iran
| | - Masoud Soleimani
- Department of Hematology, Faculty of Medical Sciences, Tarbiat Modares University, P.O. Box 14115-111, Tehran, Iran
| | - Maryam Hafizi
- Stem Cell Biology Department, Stem Cell Technology Research Center, Tehran, Iran
| | - Nasser Ghaemi
- School of Chemistry, College of Science, University of Tehran, Tehran, Iran
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464
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Muktapuram PR, Gara RK, Sharma K, Rohit C, Srinivas K, Mishra DP, Bathula SR. Anticancer siRNA delivery by new anticancer molecule: A novel combination strategy for cancer cell killing. Eur J Med Chem 2012; 56:400-8. [DOI: 10.1016/j.ejmech.2012.07.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 07/17/2012] [Accepted: 07/18/2012] [Indexed: 12/17/2022]
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465
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Chen M, Cooper HM, Zhou JZ, Bartlett PF, Xu ZP. Reduction in the size of layered double hydroxide nanoparticles enhances the efficiency of siRNA delivery. J Colloid Interface Sci 2012; 390:275-81. [PMID: 23084868 DOI: 10.1016/j.jcis.2012.09.033] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 09/12/2012] [Accepted: 09/13/2012] [Indexed: 11/19/2022]
Abstract
Small interfering RNAs (siRNAs) are a potentially powerful new class of pharmaceutical drugs for many disease. However, the delivery of unprotected siRNAs is ineffective due to their susceptibility to degradation by ubiquitous nucleases under physiological conditions. Layered double hydroxide nanoparticles (LDHs) have been found to be efficient carriers of anionic drugs and nucleic acids. Our previous research has shown that LDHs (with the Z-average particle size of approximately 110 nm) can mediate siRNA delivery in mammalian cells, resulting in gene silencing. However, short double-stranded nucleic acids are mostly adsorbed onto the external surface and not well protected by LDHs. In order to enhance the intercalation of siRNA into the LDH interlayer and the efficiency of subsequent siRNA delivery, we prepared smaller LDHs (with the Z-average particle size of approximately 45 nm) with an engineered non-aqueous method. We demonstrate here that dsDNA/siRNA is more effectively intercalated into these small LDH nanoparticles, more dsDNA/siRNA is transfected into HEK 293T cells, and more efficient silencing of the target gene is achieved using smaller LDHs. Thus, smaller LDH particles have greater potential as a delivery system for the application of RNA interference.
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Affiliation(s)
- Min Chen
- Queensland Brain Institute, The University of Queensland, Queensland 4072, Australia
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466
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Wada S, Obika S, Shibata MA, Yamamoto T, Nakatani M, Yamaoka T, Torigoe H, Harada-Shiba M. Development of a 2',4'-BNA/LNA-based siRNA for Dyslipidemia and Assessment of the Effects of Its Chemical Modifications In Vivo. MOLECULAR THERAPY. NUCLEIC ACIDS 2012; 1:e45. [PMID: 23344237 PMCID: PMC3464879 DOI: 10.1038/mtna.2012.32] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Recent advances in RNA interference (RNAi)-based drug development have partially allowed systemic administration of these agents in vivo with promising therapeutic effects. However, before chemically modified small-interfering RNAs (siRNAs) can be applied clinically, their in vivo effects should be thoroughly assessed. And while many studies have assessed the effects of chemically modified siRNAs in vitro, there has been no comprehensive assessment of their effects in vivo. Here, we aimed to elucidate the effects of administering chemically modified siRNAs in vivo and to propose a 2′,4′-bridged nucleic acid (BNA)/locked nucleic acid (LNA)-based siRNA candidate for dyslipidemia. A potentially therapeutic siRNA, siL2PT-1M, was modified with phosphorothioate (PS) and 2′,4′-BNA/LNA in its sense strand and with 2′-methoxy (2′-OMe) nucleotides in its immunostimulatory motif; administration of siL2PT-1M resulted in sustained reductions in serum total cholesterol (TC) (24 days) and a concomitant apolipoprotein B (apoB) mRNA reduction in liver without adverse effects. The 2′,4′-BNA/LNA modification in the sense strand was greatly augmented the duration of the RNAi effect, whereas cholesterol conjugation shortened the duration. Cholesterol-conjugated immunostimulatory siRNA (isRNA) induced higher serum interferon-α (IFN-α) levels than did nonmodified isRNA, indicating that the immune reaction was facilitated by cholesterol conjugation. Our results indicated that modification of the adenosine residues complementary to the immunostimulatory motif and of central 5′-UG-3′ in the sense strand would ameliorate the negative immune response.
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Affiliation(s)
- Shunsuke Wada
- 1] Department of Molecular Innovation in Lipidology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan [2] Graduate School of Chemical Sciences and Technology, Tokyo University of Science, Shinjuku-ku, Tokyo, Japan
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467
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Leconet W, Petit P, Peraldi-Roux S, Bresson D. Nonviral delivery of small interfering RNA into pancreas-associated immune cells prevents autoimmune diabetes. Mol Ther 2012; 20:2315-25. [PMID: 22990670 DOI: 10.1038/mt.2012.190] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The development of small interfering RNA (siRNA) for the treatment of human disorders has been often hampered by their low transfection efficiency in vivo. In order to overcome this major drawback, various in vivo siRNA transfection methods have been developed. However, their capacity to transfect immune or insulin-producing β-cells within the pancreas for the treatment of autoimmune diabetes remains undetermined. We found that lipid- or polyethylenimine-based delivery agents were efficient to address siRNA molecules within pancreas-associated antigen-presenting cells (APCs) (but not β-cells) and particularly a CD11b(+) cell population comprising both CD11b(+)CD11c(neg) macrophages and CD11b(+)CD11c(+) dendritic cells. However, the route of administration and the carrier composition greatly affected the transfection efficacy. Therapeutically, we showed that early (starting at 6-week-old) short-course treatment with lipid/Alox15-specific siRNA complex promoted long-term protection from type 1 diabetes (T1D) in wild-type (WT) nonobese diabetic (NOD) mice. Alox15 downregulation in pancreas-associated CD11b(+) cells significantly upregulated a variety of costimulatory molecules and particularly the programmed death 1 ligand 1 (PD-L1) pathway involved in tolerance induction. Concomitantly, we found that regulatory T cells were increased in the pancreas of lipid/Alox15 siRNA-treated NOD mice. Collectively, our data provide new insights into the development of siRNA-based therapeutics for T1D.
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Affiliation(s)
- Wilhem Leconet
- Diabetes Center, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA
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468
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Lee SJ, Son S, Yhee JY, Choi K, Kwon IC, Kim SH, Kim K. Structural modification of siRNA for efficient gene silencing. Biotechnol Adv 2012; 31:491-503. [PMID: 22985697 DOI: 10.1016/j.biotechadv.2012.09.002] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 09/07/2012] [Accepted: 09/07/2012] [Indexed: 11/16/2022]
Abstract
Small interfering RNA (siRNA) holds a great promise for the future of genomic medicine because of its highly sequence-specific gene silencing and universality in therapeutic target. The medical use of siRNA, however, has been severely hampered by the inherent physico-chemical properties of siRNA itself, such as low charge density, high structural stiffness and rapid enzymatic degradation; therefore, the establishment of efficient and safe siRNA delivery methodology is an essential prerequisite, particularly for systemic administration. For an efficient systemic siRNA delivery, it is a critical issue to obtain small and compact siRNA polyplexes with cationic condensing reagents including cationic polymers, because the size and surface properties of the polyplexes are major determinants for achieving desirable in vivo fate. Unfortunately, synthetic siRNA is not easily condensed with cationic polymers due to its intrinsic rigid structure and low spatial charge density. Accordingly, the loose siRNA polyplexes inevitably expose siRNA to the extracellular environment during systemic circulation, resulting in low therapeutic efficiency and poor biodistribution. In this review, we highlight the innovative approaches to increase the size of siRNA via structural modification of the siRNA itself. The attempts include several methodologies such as hybridization, chemical polymerization, and micro- and nano-structurization of siRNA. Due to its increased charge density and flexibility, the structured siRNA can produce highly condensed and homogenous polyplexes compared to the classical monomeric siRNA. As a result, stable and compact siRNA polyplexes can enhance serum stability and target delivery efficiency in vivo with desirable biodistribution. The review specifically aims to provide the recent progress of structural modification of siRNA. In addition, the article also briefly and concisely explains the improved physico-chemical properties of structured siRNA with respect to stability, condensation ability and gene silencing efficiency.
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Affiliation(s)
- So Jin Lee
- Center for Theragnosis, Biomedical Research Institute, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Republic of Korea
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469
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Daniel-Carlier N, Sawafta A, Passet B, Thépot D, Leroux-Coyau M, Lefèvre F, Houdebine LM, Jolivet G. Viral infection resistance conferred on mice by siRNA transgenesis. Transgenic Res 2012; 22:489-500. [PMID: 22961198 DOI: 10.1007/s11248-012-9649-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 08/28/2012] [Indexed: 11/25/2022]
Abstract
RNA interference is an attractive strategy to fight against viral diseases by targeting the mRNA of viral genes. Most studies have reported the transient delivery of small interfering RNA or small hairpin (shRNA) expression constructs. Here, we present the production of transgenic mice stably expressing shRNA or miRNA targeting the IE180 mRNA (immediate early gene) of the pseudorabies virus (PRV) which infects mice and farm animals. We firstly designed non-retroviral shRNA or miRNA expression vectors. Secondly, we selected the most efficient shRNA construct that targeted either the 5'part or 3'UTR of the IE mRNA and was able to knockdown the target gene expression in cultured cells, by measuring systematically the shRNA content and comparing this with the interfering effects. We then produced four lines of transgenic mice expressing different amounts of shRNA or miRNA in the brain but without signs of stimulation of innate immunity. Lastly, we tested their resistance to PRV infection. In all transgenic lines, we observed a significant resistance to viral challenge, the best being achieved with the shRNA construct targeting the 3'UTR of the IE gene. Viral DNA levels in the brains of infected mice were always lower in transgenic mice, even in animals that did not survive. Finally, this work reports an effective strategy to generate transgenic animals producing shRNA from non-retroviral expression vectors. Moreover, these mice are the first transgenic animal models producing shRNA with a significant antiviral effect but without any apparent shRNA toxicity.
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470
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Hamar P. Role of regulatory micro RNAs in type 2 diabetes mellitus-related inflammation. Nucleic Acid Ther 2012; 22:289-94. [PMID: 22950794 DOI: 10.1089/nat.2012.0381] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
UNLABELLED Micro RNAs (miRNAs) are small, non-coding RNAs with the function of post-transcriptional gene expression regulation. Micro RNAs may function in networks, forming a complex relationship with diseases. Alterations of specific miRNA levels have significant correlation with diseases of divergent origin, such as diabetes. Type 2 diabetes mellitus (T2DM) has an increasing worldwide epidemic with serious complications. However, T2DM is a chronic process, and from early metabolic alterations to manifest complications decades may pass, during which our diagnostic arsenal is limited. Micro RNAs may thus serve as novel diagnostic tools as well as therapeutic targets in pre-diabetes. Recent Fundings: Micro RNAs (miRNAs) involved in inflammatory processes contributing to the development of type 2 diabetes mellitus (T2DM) published mostly in the past 2 years. MiRNAs are involved in such early diabetic processes as non-alcoholic steatohepatitis (NASH) and inflammation of the visceral adipose tissue. Evidence is emerging regarding the continuous spectrum between type 1 diabetes (T1DM) and T2DM being just 2 endpoints of the same disease with different genetic background. Thus, miRNA regulation of autoimmune components in T2DM may shed new light on pathogenesis. Finally, the involvement of miRNAs in inflammation as a key driving force of diabetic complications is also summarized. CONCLUSION Inflammation is emerging as a central pathophysiological process in the development of T2DM. Visceral adipose tissue inflammation and non-alcoholic steatohepatitis together with insulitis are probably the first events leading to a complex metabolic disorder. These early events may be diagnosed or even influenced through our increasing knowledge about the involvement of post-transcriptional gene regulation by miRNAs.
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Affiliation(s)
- Péter Hamar
- Semmelweis University, Institute of Pathophysiology, Budapest, Hungary.
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471
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Ahn J, Woo HN, Ko A, Khim M, Kim C, Park NH, Song HY, Kim SW, Lee H. Multispecies-compatible antitumor effects of a cross-species small-interfering RNA against mammalian target of rapamycin. Cell Mol Life Sci 2012; 69:3147-58. [PMID: 22562582 PMCID: PMC11115121 DOI: 10.1007/s00018-012-0998-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2011] [Revised: 04/11/2012] [Accepted: 04/12/2012] [Indexed: 12/11/2022]
Abstract
Successful development of sequence-specific siRNA (small interfering RNA)-based drugs requires an siRNA design that functions consistently in different organisms. Utilizing the CAPSID program previously developed by our group, we here designed siRNAs against mammalian target of rapamycin (mTOR) that are entirely complementary among various species and investigated their multispecies-compatible gene-silencing properties. The mTOR siRNAs markedly reduced mTOR expression at both the mRNA and protein levels in human, mouse, and monkey cell lines. The reduction in mTOR expression resulted in inactivation of both mTOR complex I and II signaling pathways, as confirmed by reduced phosphorylation of p70S6K (70-kDa ribosomal protein S6 kinase), 4EBP1 (eIF4E-binding protein 1), and AKT, and nuclear accumulation of FOXO1 (forkhead box O1), with consequent cell-cycle arrest, proliferation inhibition, and autophagy activation. Moreover, interfering with mTOR activity in vivo using mTOR small-hairpin RNA-expressing recombinant adeno-associated virus led to significant antitumor effects in xenograft and allograft models. Thus, the present study demonstrates that cross-species siRNA successfully silences its target and readily produces multispecies-compatible phenotypic alterations-antitumor effects in the case of mTOR siRNA. Application of cross-species siRNA should greatly facilitate the development of siRNA-based therapeutic agents.
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Affiliation(s)
- Jeonghyun Ahn
- Department of Microbiology, University of Ulsan College of Medicine, 86 Asanbyeongwon-Gil Songpa-Gu, Seoul, Korea
- Bio-Medical Research Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Ha-Na Woo
- Department of Microbiology, University of Ulsan College of Medicine, 86 Asanbyeongwon-Gil Songpa-Gu, Seoul, Korea
- Bio-Medical Research Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Ara Ko
- Department of Microbiology, University of Ulsan College of Medicine, 86 Asanbyeongwon-Gil Songpa-Gu, Seoul, Korea
| | - Maria Khim
- Department of Microbiology, University of Ulsan College of Medicine, 86 Asanbyeongwon-Gil Songpa-Gu, Seoul, Korea
| | - Catherine Kim
- Department of Microbiology, University of Ulsan College of Medicine, 86 Asanbyeongwon-Gil Songpa-Gu, Seoul, Korea
| | - Nung Hwa Park
- Bio-Medical Research Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Ho-Young Song
- Department of Radiology, University of Ulsan College of Medicine, Seoul, Korea
- Asan Medical Center, Seoul, Korea
| | - Seong Who Kim
- Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul, Korea
- Bio-Medical Institute of Technology, University of Ulsan College of Medicine, Seoul, Korea
- Cellular Dysfunction Research Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Heuiran Lee
- Department of Microbiology, University of Ulsan College of Medicine, 86 Asanbyeongwon-Gil Songpa-Gu, Seoul, Korea
- Bio-Medical Institute of Technology, University of Ulsan College of Medicine, Seoul, Korea
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472
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Functional RNA delivery targeted to dendritic cells by synthetic nanoparticles. Ther Deliv 2012; 3:1077-99. [DOI: 10.4155/tde.12.90] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Dendritic cells (DCs) are essential to many aspects of immune defense development and regulation. They provide important targets for prophylactic and therapeutic delivery. While protein delivery has had considerable success, RNA delivery is still expanding. Delivering RNA molecules for RNAi has shown particular success and there are reports on successful delivery of mRNA. Central, therein, is the application of cationic entities. Following endocytosis of the delivery vehicle for the RNA, cationic entities should promote vesicular membrane perturbation, facilitating cytosolic release. The present review explains the diversity of DC function in immune response development and control. Promotion of delivered RNA cytosolic release is discussed, relating to immunoprophylactic and therapeutic potential, and DC endocytic machinery is reviewed, showing how DC endocytic pathways influence the handling of internalized material. The potential advantages for application of replicating RNA are presented and discussed, in consideration of their value and development in the near future.
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473
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Abstract
The development of nanoscale delivery vehicles for siRNAs is a current topic of considerable importance. However, little is understood about the exact trafficking mechanisms for siRNA-vehicle complexes across the plasma membrane and into the cytoplasm. While some information can be gleaned from studies on delivery of plasmid DNA, the different delivery requirements for these two vehicles makes drawing specific conclusions a challenge. However, using chemical inhibitors of different endocytosis pathways, studies on which endocytotic pathways are advantageous and deleterious for the delivery of nucleic acid drugs are emerging. Using this information as a guide, it is expected that the future development of effective siRNA delivery vehicles and therapeutics will be greatly improved.
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Affiliation(s)
- Amanda P Malefyt
- Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan 48824
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474
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Boudreau RL, Spengler RM, Hylock RH, Kusenda BJ, Davis HA, Eichmann DA, Davidson BL. siSPOTR: a tool for designing highly specific and potent siRNAs for human and mouse. Nucleic Acids Res 2012; 41:e9. [PMID: 22941647 PMCID: PMC3592398 DOI: 10.1093/nar/gks797] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
RNA interference (RNAi) serves as a powerful and widely used gene silencing tool for basic biological research and is being developed as a therapeutic avenue to suppress disease-causing genes. However, the specificity and safety of RNAi strategies remains under scrutiny because small inhibitory RNAs (siRNAs) induce off-target silencing. Currently, the tools available for designing siRNAs are biased toward efficacy as opposed to specificity. Prior work from our laboratory and others’ supports the potential to design highly specific siRNAs by limiting the promiscuity of their seed sequences (positions 2–8 of the small RNA), the primary determinant of off-targeting. Here, a bioinformatic approach to predict off-targeting potentials was established using publically available siRNA data from more than 50 microarray experiments. With this, we developed a specificity-focused siRNA design algorithm and accompanying online tool which, upon validation, identifies candidate sequences with minimal off-targeting potentials and potent silencing capacities. This tool offers researchers unique functionality and output compared with currently available siRNA design programs. Furthermore, this approach can greatly improve genome-wide RNAi libraries and, most notably, provides the only broadly applicable means to limit off-targeting from RNAi expression vectors.
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Affiliation(s)
- Ryan L Boudreau
- Department of Internal Medicine, Program in Molecular & Cellular Biology, Institute for Clinical & Translational Science, University of Iowa, Iowa City, IA 52242, USA
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475
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Yu D, Pendergraff H, Liu J, Kordasiewicz HB, Cleveland DW, Swayze EE, Lima WF, Crooke ST, Prakash TP, Corey DR. Single-stranded RNAs use RNAi to potently and allele-selectively inhibit mutant huntingtin expression. Cell 2012; 150:895-908. [PMID: 22939619 PMCID: PMC3444165 DOI: 10.1016/j.cell.2012.08.002] [Citation(s) in RCA: 218] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 05/31/2012] [Accepted: 08/01/2012] [Indexed: 01/23/2023]
Abstract
Mutant huntingtin (HTT) protein causes Huntington disease (HD), an incurable neurological disorder. Silencing mutant HTT using nucleic acids would eliminate the root cause of HD. Developing nucleic acid drugs is challenging, and an ideal clinical approach to gene silencing would combine the simplicity of single-stranded antisense oligonucleotides with the efficiency of RNAi. Here, we describe RNAi by single-stranded siRNAs (ss-siRNAs). ss-siRNAs are potent (>100-fold more than unmodified RNA) and allele-selective (>30-fold) inhibitors of mutant HTT expression in cells derived from HD patients. Strategic placement of mismatched bases mimics micro-RNA recognition and optimizes discrimination between mutant and wild-type alleles. ss-siRNAs require Argonaute protein and function through the RNAi pathway. Intraventricular infusion of ss-siRNA produced selective silencing of the mutant HTT allele throughout the brain in a mouse HD model. These data demonstrate that chemically modified ss-siRNAs function through the RNAi pathway and provide allele-selective compounds for clinical development.
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Affiliation(s)
- Dongbo Yu
- Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, Texas, USA, 75390-9041
| | - Hannah Pendergraff
- Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, Texas, USA, 75390-9041
| | - Jing Liu
- Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, Texas, USA, 75390-9041
| | - Holly B. Kordasiewicz
- Department of Cellular and Molecular Medicine, Univ. of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093-0670
- Isis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, California, USA, 92010
| | - Don W. Cleveland
- Department of Cellular and Molecular Medicine, Univ. of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093-0670
| | - Eric E. Swayze
- Isis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, California, USA, 92010
| | - Walt F. Lima
- Isis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, California, USA, 92010
| | - Stanley T. Crooke
- Isis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, California, USA, 92010
| | - Thazha P. Prakash
- Isis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, California, USA, 92010
| | - David R. Corey
- Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, Texas, USA, 75390-9041
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476
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Suma T, Miyata K, Anraku Y, Watanabe S, Christie RJ, Takemoto H, Shioyama M, Gouda N, Ishii T, Nishiyama N, Kataoka K. Smart multilayered assembly for biocompatible siRNA delivery featuring dissolvable silica, endosome-disrupting polycation, and detachable PEG. ACS NANO 2012; 6:6693-6705. [PMID: 22835034 DOI: 10.1021/nn301164a] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Multifunctional delivery systems of small interfering RNA (siRNA) are needed to overcome the intrinsic biological barriers toward efficient gene silencing in the cell cytoplasm. In this report, a smart multilayered assembly (SMA) was fabricated by a layer-by-layer method with polyionic materials. The SMA was designed to feature a siRNA-loaded core, a transiently core-stabilizing silica interlayer, an endosome-disrupting polycation interlayer, and a biocompatible poly(ethylene glycol) (PEG) shell with reductive environment-responsive detachability. The SMA was confirmed to be approximately 160 nm in size with narrow distribution and spherical morphology by DLS and TEM analyses. The PEG detachability of the SMA based on disulfide cleavage was also confirmed by the increase in both ζ-potential and size due to the exposure of the polycation interlayer and the compromised colloidal stability. The silica interlayer rendered the SMA highly tolerant to dissociation induced by anionic lipids, while after 24 h dialysis siRNA release from the SMA was clearly observed, presumably due to gradual dissolution of the silica interlayer based on the equilibrium shift to silicate ions. The entrapment ratio of siRNA delivered by the SMA within the endosome was significantly lower than that by nondisulfide control (NDC) without PEG detachability, suggesting the improved endosomal escape of SMA with the exposed, endosome-disrupting interlayer after PEG detachment. SMAs induced significantly higher gene silencing efficiency in various cultured cells, compared to NDC, without associated cytotoxicity. The systemic administration of SMAs for subcutaneous tumor-bearing mice achieved significant endogenous gene silencing in tumor tissue without hematological toxicity.
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Affiliation(s)
- Tomoya Suma
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Tokyo 113-8656, Japan
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477
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Manipulation of Cell Physiology Enables Gene Silencing in Well-differentiated Airway Epithelia. MOLECULAR THERAPY-NUCLEIC ACIDS 2012; 1:e41. [PMID: 23344182 PMCID: PMC3437804 DOI: 10.1038/mtna.2012.36] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The application of RNA interference-based gene silencing to the airway surface epithelium holds great promise to manipulate host and pathogen gene expression for therapeutic purposes. However, well-differentiated airway epithelia display significant barriers to double-stranded small-interfering RNA (siRNA) delivery despite testing varied classes of nonviral reagents. In well-differentiated primary pig airway epithelia (PAE) or human airway epithelia (HAE) grown at the air–liquid interface (ALI), the delivery of a Dicer-substrate small-interfering RNA (DsiRNA) duplex against hypoxanthine–guanine phosphoribosyltransferase (HPRT) with several nonviral reagents showed minimal uptake and no knockdown of the target. In contrast, poorly differentiated cells (2–5-day post-seeding) exhibited significant oligonucleotide internalization and target knockdown. This finding suggested that during differentiation, the barrier properties of the epithelium are modified to an extent that impedes oligonucleotide uptake. We used two methods to overcome this inefficiency. First, we tested the impact of epidermal growth factor (EGF), a known enhancer of macropinocytosis. Treatment of the cells with EGF improved oligonucleotide uptake resulting in significant but modest levels of target knockdown. Secondly, we used the connectivity map (Cmap) database to correlate gene expression changes during small molecule treatments on various cells types with genes that change upon mucociliary differentiation. Several different drug classes were identified from this correlative assessment. Well-differentiated epithelia treated with DsiRNAs and LY294002, a PI3K inhibitor, significantly improved gene silencing and concomitantly reduced target protein levels. These novel findings reveal that well-differentiated airway epithelia, normally resistant to siRNA delivery, can be pretreated with small molecules to improve uptake of synthetic oligonucleotide and RNA interference (RNAi) responses.
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478
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Bramsen JB, Kjems J. Development of Therapeutic-Grade Small Interfering RNAs by Chemical Engineering. Front Genet 2012; 3:154. [PMID: 22934103 PMCID: PMC3422727 DOI: 10.3389/fgene.2012.00154] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 07/31/2012] [Indexed: 12/25/2022] Open
Abstract
Recent successes in clinical trials have provided important proof of concept that small interfering RNAs (siRNAs) indeed constitute a new promising class of therapeutics. Although great efforts are still needed to ensure efficient means of delivery in vivo, the siRNA molecule itself has been successfully engineered by chemical modification to meet initial challenges regarding specificity, stability, and immunogenicity. To date, a great wealth of siRNA architectures and types of chemical modification are available for promoting safe siRNA-mediated gene silencing in vivo and, consequently, the choice of design and modification types can be challenging to individual experimenters. Here we review the literature and devise how to improve siRNA performance by structural design and specific chemical modification to ensure potent and specific gene silencing without unwarranted side-effects and hereby complement the ongoing efforts to improve cell targeting and delivery by other carrier molecules.
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Affiliation(s)
- Jesper B Bramsen
- Interdisciplinary Nanoscience Center, Department of Molecular Biology and Genetics, Aarhus University Aarhus C, Denmark
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479
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A microRNA network regulates expression and biosynthesis of wild-type and DeltaF508 mutant cystic fibrosis transmembrane conductance regulator. Proc Natl Acad Sci U S A 2012. [PMID: 22853952 DOI: 10.1073/+pnas.1210906109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Production of functional proteins requires multiple steps, including gene transcription and posttranslational processing. MicroRNAs (miRNAs) can regulate individual stages of these processes. Despite the importance of the cystic fibrosis transmembrane conductance regulator (CFTR) channel for epithelial anion transport, how its expression is regulated remains uncertain. We discovered that miRNA-138 regulates CFTR expression through its interactions with the transcriptional regulatory protein SIN3A. Treating airway epithelia with an miR-138 mimic increased CFTR mRNA and also enhanced CFTR abundance and transepithelial Cl(-) permeability independent of elevated mRNA levels. An miR-138 anti-miR had the opposite effects. Importantly, miR-138 altered the expression of many genes encoding proteins that associate with CFTR and may influence its biosynthesis. The most common CFTR mutation, ΔF508, causes protein misfolding, protein degradation, and cystic fibrosis. Remarkably, manipulating the miR-138 regulatory network also improved biosynthesis of CFTR-ΔF508 and restored Cl(-) transport to cystic fibrosis airway epithelia. This miRNA-regulated network directs gene expression from the chromosome to the cell membrane, indicating that an individual miRNA can control a cellular process more broadly than recognized previously. This discovery also provides therapeutic avenues for restoring CFTR function to cells affected by the most common cystic fibrosis mutation.
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480
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Abstract
rAAV vectors have emerged as one of the leading gene transfer systems in preclinical and clinical applications. Promising intrinsic features of this vector system are nonpathogenicity, high stability and low immunogenicity. Application of the vector system has been improved by simplifying the production procedure and by expanding the vector platform using alternative serotypes and vectors with artificial capsids (mosaic, hybrid or specifically engineered). The current limitations of the vector system are addressed based on the increasing knowledge on the virus-host interaction by further optimizing the capsid as well as the vector genome.
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481
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Zhang J, Zheng J, Lu C, Du Q, Liang Z, Xi Z. Modification of the siRNA passenger strand by 5-nitroindole dramatically reduces its off-target effects. Chembiochem 2012; 13:1940-5. [PMID: 22887813 DOI: 10.1002/cbic.201200349] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Indexed: 12/16/2022]
Abstract
During the formation of RNA-induced silencing complex (RISC), the passenger and guide strand of an siRNA duplex separate from each other to generate an active RISC complex. Accumulating evidence shows that an siRNA passenger strand can also assemble into a RISC complex and mediate RNA interference, thereby causing undesired off-target effects. To reduce this effect, the so-called "universal base" 5-nitroindole nucleotides were incorporated into an siRNA passenger strand. Melting temperature and circular dichroism spectrum measurements showed no significant changes compared to the unmodified duplex, thus indicating the formation of normal A-form conformation. Using a dual luciferase reporter assay, we have further shown that 5-nitroindole modification at position 15 of the siRNA passenger strand drastically decreased the RNAi (RNA interfering) potency of this strand, whereas the potency of the RNA guide strand was not much affected. These results could provide a practical approach for reducing off-target effects mediated by the siRNA passenger strand.
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Affiliation(s)
- Junbin Zhang
- Department of Chemical Biology and State Key Laboratory of Elemento-organic Chemistry, Nankai University, Tianjin, China
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482
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Hoyer J, Neundorf I. Knockdown of a G protein-coupled receptor through efficient peptide-mediated siRNA delivery. J Control Release 2012; 161:826-34. [DOI: 10.1016/j.jconrel.2012.05.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 05/05/2012] [Accepted: 05/08/2012] [Indexed: 12/18/2022]
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483
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A microRNA network regulates expression and biosynthesis of wild-type and DeltaF508 mutant cystic fibrosis transmembrane conductance regulator. Proc Natl Acad Sci U S A 2012; 109:13362-7. [PMID: 22853952 DOI: 10.1073/pnas.1210906109] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Production of functional proteins requires multiple steps, including gene transcription and posttranslational processing. MicroRNAs (miRNAs) can regulate individual stages of these processes. Despite the importance of the cystic fibrosis transmembrane conductance regulator (CFTR) channel for epithelial anion transport, how its expression is regulated remains uncertain. We discovered that miRNA-138 regulates CFTR expression through its interactions with the transcriptional regulatory protein SIN3A. Treating airway epithelia with an miR-138 mimic increased CFTR mRNA and also enhanced CFTR abundance and transepithelial Cl(-) permeability independent of elevated mRNA levels. An miR-138 anti-miR had the opposite effects. Importantly, miR-138 altered the expression of many genes encoding proteins that associate with CFTR and may influence its biosynthesis. The most common CFTR mutation, ΔF508, causes protein misfolding, protein degradation, and cystic fibrosis. Remarkably, manipulating the miR-138 regulatory network also improved biosynthesis of CFTR-ΔF508 and restored Cl(-) transport to cystic fibrosis airway epithelia. This miRNA-regulated network directs gene expression from the chromosome to the cell membrane, indicating that an individual miRNA can control a cellular process more broadly than recognized previously. This discovery also provides therapeutic avenues for restoring CFTR function to cells affected by the most common cystic fibrosis mutation.
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484
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Designed guanidinium-rich amphipathic oligocarbonate molecular transporters complex, deliver and release siRNA in cells. Proc Natl Acad Sci U S A 2012; 109:13171-6. [PMID: 22847412 DOI: 10.1073/pnas.1211361109] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The polyanionic nature of oligonucleotides and their enzymatic degradation present challenges for the use of siRNA in research and therapy; among the most notable of these is clinically relevant delivery into cells. To address this problem, we designed and synthesized the first members of a new class of guanidinium-rich amphipathic oligocarbonates that noncovalently complex, deliver, and release siRNA in cells, resulting in robust knockdown of target protein synthesis in vitro as determined using a dual-reporter system. The organocatalytic oligomerization used to synthesize these co-oligomers is step-economical and broadly tunable, affording an exceptionally quick strategy to explore chemical space for optimal siRNA delivery in varied applications. The speed and versatility of this approach and the biodegradability of the designed agents make this an attractive strategy for biological tool development, imaging, diagnostics, and therapeutic applications.
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485
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Abstract
RNA interference (RNAi) is a promising strategy to suppress the expression of disease-relevant genes and induce post-transcriptional gene silencing. Their simplicity and stability endow RNAi with great advantages in molecular medicine. Several RNAi-based drugs are in various stages of clinical investigation. This review summarizes the ongoing research endeavors on RNAi in molecular medicine, delivery systems for RNAi-based drugs, and a compendium of RNAi drugs in different stages of clinical development. Of special interest are RNAi-based drug target discovery and validation, delivery systems for RNAi-based drugs, such as nanoparticles, rabies virus protein-based vehicles, and bacteriophages for RNA packaging.
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Affiliation(s)
- Jing Chen
- Institute of Modern, Biopharmaceuticals, State Key, Laboratory Breeding Base of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China
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486
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Miele E, Spinelli GP, Miele E, Di Fabrizio E, Ferretti E, Tomao S, Gulino A. Nanoparticle-based delivery of small interfering RNA: challenges for cancer therapy. Int J Nanomedicine 2012; 7:3637-57. [PMID: 22915840 PMCID: PMC3418108 DOI: 10.2147/ijn.s23696] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Indexed: 12/18/2022] Open
Abstract
During recent decades there have been remarkable advances and profound changes in cancer therapy. Many therapeutic strategies learned at the bench, including monoclonal antibodies and small molecule inhibitors, have been used at the bedside, leading to important successes. One of the most important advances in biology has been the discovery that small interfering RNA (siRNA) is able to regulate the expression of genes, by a phenomenon known as RNA interference (RNAi). RNAi is one of the most rapidly growing fields of research in biology and therapeutics. Much research effort has gone into the application of this new discovery in the treatment of various diseases, including cancer. However, even though these molecules may have potential and strong utility, some limitations make their clinical application difficult, including delivery problems, side effects due to off-target actions, disturbance of physiological functions of the cellular machinery involved in gene silencing, and induction of the innate immune response. Many researchers have attempted to overcome these limitations and to improve the safety of potential RNAi-based therapeutics. Nanoparticles, which are nanostructured entities with tunable size, shape, and surface, as well as biological behavior, provide an ideal opportunity to modify current treatment regimens in a substantial way. These nanoparticles could be designed to surmount one or more of the barriers encountered by siRNA. Nanoparticle drug formulations afford the chance to improve drug bioavailability, exploiting superior tissue permeability, payload protection, and the “stealth” features of these entities. The main aims of this review are: to explain the siRNA mechanism with regard to potential applications in siRNA-based cancer therapy; to discuss the possible usefulness of nanoparticle-based delivery of certain molecules for overcoming present therapeutic limitations; to review the ongoing relevant clinical research with its pitfalls and promises; and to evaluate critically future perspectives and challenges in siRNA-based cancer therapy.
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Affiliation(s)
- Evelina Miele
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
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487
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Roth W, Hatzfeld M, Magin TM. Targeting the palm: a leap forward toward treatment of keratin disorders. J Invest Dermatol 2012; 132:1541-2. [PMID: 22584502 DOI: 10.1038/jid.2012.99] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Any rational therapy benefits from an understanding of basic biology and the simplicity of its strategy. Among keratinopathies, epidermolytic palmoplantar keratoderma stands out by virtue of hotspot mutations in the KRT9 gene, exclusively expressed in the palmoplantar epidermis. In this issue, Leslie Pedrioli et al. report on the successful application of KRT9-specific siRNAs in cultured cells and in a mouse model. The study beautifully illustrates the potency of a thorough experimental approach and the challenges that remain, especially in its delivery.
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Affiliation(s)
- Wera Roth
- Division of Cell and Developmental Biology, Translational Centre for Regenerative Medicine and Institute of Biology, University of Leipzig, Leipzig, Germany
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488
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Abstract
Over the past two decades, gene therapy has garnered tremendous attention and is heralded by many as the ultimate cure to treat diseases such as cancer, viral infections, and inherited genetic disorders. However, the therapeutic applications of nucleic acids extend beyond the delivery of double-stranded DNA and subsequent expression of deficient gene products in diseased tissue. Other strategies include antisense oligonucleotides and most notably RNA interference (RNAi). Antisense strategies bear great potential for the treatment of diseases that are caused by misspliced mRNA, and RNAi is a universal and extraordinarily efficient tool to knock down the expression of virtually any gene by specific degradation of the desired target mRNA. However, because of the hurdles associated with effective delivery of nucleic acids across a cell membrane, the initial euphoria surrounding siRNA therapy soon subsided. The ability of oligonucleotides to cross the plasma membrane is hampered by their size and highly negative charge. Viral vectors have long been the gold standard to overcome this barrier, but they are associated with severe immunogenic effects and possible tumorigenesis. Cell-penetrating peptides (CPPs), cationic peptides that can translocate through the cell membrane independent of receptors and can transport cargo including proteins, small organic molecules, nanoparticles, and oligonucleotides, represent a promising class of nonviral delivery vectors. This Account focuses on peptide carrier systems for the cellular delivery of various types of therapeutic nucleic acids with a special emphasis on cell-penetrating peptides. We also emphasize the clinical relevance of this research through examples of promising in vivo studies. Although CPPs are often derived from naturally occurring protein transduction domains, they can also be artificially designed. Because CPPs typically include many positively charged amino acids, those electrostatic interactions facilitate the formation of complexes between the carriers and the oligonucleotides. One drawback of CPP-mediated delivery includes entrapment of the cargo in endosomes because uptake tends to be endocytic: coupling of fatty acids or endosome-disruptive peptides to the CPPs can overcome this problem. CPPs can also lack specificity for a single cell type, which can be addressed through the use of targeting moieties, such as peptide ligands that bind to specific receptors. Researchers have also applied these strategies to cationic carrier systems for nonviral oligonucleotide delivery, such as liposomes or polymers, but CPPs tend to be less cytotoxic than other delivery vehicles.
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Affiliation(s)
- Jan Hoyer
- Translational Centre for Regenerative Medicine, University of Leipzig, Philipp-Rosenthal-Strasse 55, 04103 Leipzig, Germany
| | - Ines Neundorf
- Translational Centre for Regenerative Medicine, University of Leipzig, Philipp-Rosenthal-Strasse 55, 04103 Leipzig, Germany
- Institute of Biochemistry, Department of Chemistry, University of Cologne, Zülpicher Strasse 47, 50674 Cologne, Germany
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489
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Abstract
The promise of short RNA or DNA segments such as siRNAs, antisense oligonucleotides, and transcription factor decoys to treat disease has prompted nearly 40 clinical trials for RNA interference (RNAi)-based therapeutics and more than 100 clinical trials for antisense oligonucleotide-based technologies; in fact, there are promising in vivo and preclinical studies for many hundreds of technologies. Current treatment strategies are largely injection-based, so effective oral delivery platforms for oligonucleotides may result in improved patient comfort and compliance. We analyze recently developed oral delivery methods for short RNA and DNA segments.
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490
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Low WC, Yau WWY, Stanton LW, Marcy G, Goh E, Chew SY. Directing neuronal differentiation of primary neural progenitor cells by gene knockdown approach. DNA Cell Biol 2012; 31:1148-60. [PMID: 22339269 PMCID: PMC3391493 DOI: 10.1089/dna.2011.1557] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 01/10/2012] [Accepted: 01/12/2012] [Indexed: 01/07/2023] Open
Abstract
Directing differentiation of neural stem/progenitor cells (NPCs) to produce functional neurons is a promising remedy for neural pathological conditions. The major challenge, however, lies in the effective and efficient generation of a sizable population of neurons. A potential strategy is to incorporate RNA interference (RNAi) during directed stem cell differentiation to recapitulate the complex cell-signaling cascades that often occurs during the process. In this study, in vitro silencing of RE1-silencing transcription factor (REST) was carried out using small-interfering RNAs (siRNAs) to evaluate the efficacy of combining REST knockdown with conventional differentiation approaches to enhance neurogenesis. While earlier studies have demonstrated enhanced neuronal lineage commitment from embryonic stem cells and mesenchymal stem cells upon REST knockdown, the effects of REST silencing during other stages of neural development have not been extensively evaluated. We hypothesize that REST knockdown would enhance NPC development to mature neurons and that induced REST silencing can serve as a potential biochemical approach to direct cell fate. Under nonspecific induction conditions, REST knockdown induced eightfold higher Tuj1 mRNA expression at day 14 compared with untransfected cells and cells subjected to scrambled-siRNA treatment (controls). Immunostaining also revealed greater percentage of Tuj1 positive cells with REST knockdown. Combined with neuronal induction, REST silencing enhanced the kinetics of neuronal differentiation and the rate of maturation of committed neuronal cells. Specifically, upregulation of MAP2 occurred as early as 3 days after induction with REST silencing and the expression was comparable to the controls at day 14. Likewise, downregulation of REST generated more than twice the percentage of Tuj1 and MAP2 positive cells compared with controls at day 5 (p<0.05). Morphologically, REST-silencing enhanced the number and length of neurite extensions from Tuj1 positive cells (p<0.05), which was not evaluated in previous differentiation studies with REST knockdown. Taken together, these results demonstrate the efficacy of combining REST silencing during directed NPC differentiation to enhance the rate of differentiation and subsequent maturation of NPCs. This study also highlights the potential of RNAi as a biomedical strategy for guided stem cell differentiation.
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Affiliation(s)
- Wei Ching Low
- Division of Chemical and Biomolecular Engineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore
| | - Winifred Wing Yiu Yau
- Division of Chemical and Biomolecular Engineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore
| | - Lawrence W. Stanton
- Stem Cell and Developmental Biology Group, Genome Institute of Singapore, Singapore, Singapore
| | - Guillaume Marcy
- Duke-NUS Graduate Medical School, National University of Singapore, Singapore, Singapore
| | - Eyleen Goh
- Duke-NUS Graduate Medical School, National University of Singapore, Singapore, Singapore
| | - Sing Yian Chew
- Division of Chemical and Biomolecular Engineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore
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491
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Hymel D, Peterson BR. Synthetic cell surface receptors for delivery of therapeutics and probes. Adv Drug Deliv Rev 2012; 64:797-810. [PMID: 22401875 PMCID: PMC3359398 DOI: 10.1016/j.addr.2012.02.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Revised: 02/18/2012] [Accepted: 02/20/2012] [Indexed: 11/17/2022]
Abstract
Receptor-mediated endocytosis is a highly efficient mechanism for cellular uptake of membrane-impermeant ligands. Cells use this process to acquire nutrients, initiate signal transduction, promote development, regulate neurotransmission, and maintain homeostasis. Natural receptors that participate in receptor-mediated endocytosis are structurally diverse, ranging from large transmembrane proteins to small glycolipids embedded in the outer leaflet of cellular plasma membranes. Despite their vast structural differences, these receptors share common features of binding to extracellular ligands, clustering in dynamic membrane regions that pinch off to yield intracellular vesicles, and accumulation of receptor-ligand complexes in membrane-sealed endosomes. Receptors typically dissociate from ligands in endosomes and cycle back to the cell surface, whereas internalized ligands are usually delivered into lysosomes, where they are degraded, but some can escape and penetrate into the cytosol. Here, we review efforts to develop synthetic cell surface receptors, defined as nonnatural compounds, exemplified by mimics of cholesterol, that insert into plasma membranes, bind extracellular ligands including therapeutics, probes, and endogenous proteins, and engage endocytic membrane trafficking pathways. By mimicking natural mechanisms of receptor-mediated endocytosis, synthetic cell surface receptors have the potential to function as prosthetic molecules capable of seamlessly augmenting the endocytic uptake machinery of living mammalian cells.
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Affiliation(s)
- David Hymel
- Department of Medicinal Chemistry, The University of Kansas, Lawrence, KS 66045, United States
| | - Blake R. Peterson
- Department of Medicinal Chemistry, The University of Kansas, Lawrence, KS 66045, United States
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492
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Leslie Pedrioli DM, Fu DJ, Gonzalez-Gonzalez E, Contag CH, Kaspar RL, Smith FJ, Irwin McLean W. Generic and Personalized RNAi-Based Therapeutics for a Dominant-Negative Epidermal Fragility Disorder. J Invest Dermatol 2012; 132:1627-35. [DOI: 10.1038/jid.2012.28] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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493
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Lee CY, Johnson RL, Wichterman-Kouznetsova J, Guha R, Ferrer M, Tuzmen P, Martin SE, Zhu W, DePamphilis ML. High-throughput screening for genes that prevent excess DNA replication in human cells and for molecules that inhibit them. Methods 2012; 57:234-48. [PMID: 22503772 PMCID: PMC4149752 DOI: 10.1016/j.ymeth.2012.03.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 03/27/2012] [Accepted: 03/29/2012] [Indexed: 12/13/2022] Open
Abstract
High-throughput screening (HTS) provides a rapid and comprehensive approach to identifying compounds that target specific biological processes as well as genes that are essential to those processes. Here we describe a HTS assay for small molecules that induce either DNA re-replication or endoreduplication (i.e. excess DNA replication) selectively in cells derived from human cancers. Such molecules will be useful not only to investigate cell division and differentiation, but they may provide a novel approach to cancer chemotherapy. Since induction of DNA re-replication results in apoptosis, compounds that selectively induce DNA re-replication in cancer cells without doing so in normal cells could kill cancers in vivo without preventing normal cell proliferation. Furthermore, the same HTS assay can be adapted to screen siRNA molecules to identify genes whose products restrict genome duplication to once per cell division. Some of these genes might regulate the formation of terminally differentiated polyploid cells during normal human development, whereas others will prevent DNA re-replication during each cell division. Based on previous studies, we anticipate that one or more of the latter genes will prove to be essential for proliferation of cancer cells but not for normal cells, since many cancer cells are deficient in mechanisms that maintain genome stability.
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Affiliation(s)
- Chrissie Y. Lee
- National Institute of Child Health and Human Development, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892-2753, United States
| | - Ronald L. Johnson
- NIH Center for Translational Therapeutics, Probe Development Branch, 9800 Medical Center Drive, Rockville, MD 20892-3370, United States
| | - Jennifer Wichterman-Kouznetsova
- NIH Center for Translational Therapeutics, Probe Development Branch, 9800 Medical Center Drive, Rockville, MD 20892-3370, United States
| | - Rajarshi Guha
- NIH Center for Translational Therapeutics, Probe Development Branch, 9800 Medical Center Drive, Rockville, MD 20892-3370, United States
| | - Marc Ferrer
- NIH Center for Translational Therapeutics, Probe Development Branch, 9800 Medical Center Drive, Rockville, MD 20892-3370, United States
| | - Pinar Tuzmen
- NIH Center for Translational Therapeutics, Chemical Genomics Branch, 5 Research Court, Room 1A13, Rockville, MD 20850, United States
| | - Scott E. Martin
- NIH Center for Translational Therapeutics, Chemical Genomics Branch, 5 Research Court, Room 1A13, Rockville, MD 20850, United States
| | - Wenge Zhu
- National Institute of Child Health and Human Development, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892-2753, United States
| | - Melvin L. DePamphilis
- National Institute of Child Health and Human Development, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892-2753, United States
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494
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Krol S, Ellis-Behnke R, Marchetti P. Nanomedicine for treatment of diabetes in an aging population: state-of-the-art and future developments. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2012; 8 Suppl 1:S69-76. [PMID: 22640905 DOI: 10.1016/j.nano.2012.05.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 12/01/2011] [Accepted: 12/03/2011] [Indexed: 01/05/2023]
Abstract
Nowadays diabetes, especially type 2 diabetes (which is strongly related to the Western diet and life-style), has developed worldwide into an epidemic disease. Nanomedicine aims to provide novel tools for diagnosis, therapy and point-of-care management of patients. Several nanotechnological approaches were developed to improve life quality for patients with insulin-dependent diabetes. They facilitate blood glucose management by non-invasive glucose measurement as well as insulin administration mainly by delivering the fragile protein as protected and targeted formulation via nasal or oral route. In the present review the oral or nasal insulin delivery by polymeric nanoparticles is discussed with focus on physiological change either related to the disease, diabetes or age-related metabolic variations influencing insulin release and bioavailability. One critical point is that new generations of targeted nanoparticle based drugs are developed and optimized for certain metabolic conditions. These conditions may change with age or disease. The influence of age-related factors such as immaturity in very young age, metabolic and physiologic changes in old age or insufficient animal models are still under-investigated not only in nanomedicine but also generally in pharmacology. Summarizing it can be noted that the bioavailability of insulin administered via routes others than subcutaneously is comparably low (max. 60%). Moreover factors like changed gut permeability as described for diabetes type 1 or other metabolic peculiarities such as insulin resistance in case of type 2 diabetes also play a role in affecting the development of novel nanoparticulated drug preparations and can be responsible for unsuccessful translation of promising animal results into human therapy. In future insulin nanoparticle development for diabetes must consider not only requirements imposed by the drug but also metabolic changes inflicted by disease or by age. Moreover new approaches are required for prevention of the disease.
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Affiliation(s)
- Silke Krol
- Fondazione IRCCS Istituto Neurologico Carlo Besta, IFOM-IEO-Campus, via Adamello 16, 201394 Milan, Italy.
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495
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Moon SL, Barnhart MD, Wilusz J. Inhibition and avoidance of mRNA degradation by RNA viruses. Curr Opin Microbiol 2012; 15:500-5. [PMID: 22626865 DOI: 10.1016/j.mib.2012.04.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 04/27/2012] [Indexed: 11/27/2022]
Abstract
The cellular mRNA decay machinery plays a major role in regulating the quality and quantity of gene expression in cells. This machinery involves multiple enzymes and pathways that converge to promote the exonucleolytic decay of mRNAs. The transcripts made by RNA viruses are susceptible to degradation by this machinery and, in fact, can be actively targeted. Thus, to maintain gene expression and replication, RNA viruses have evolved a number of strategies to avoid and/or inactivate aspects of the cellular mRNA decay machinery. Recent work uncovering the mechanisms used by RNA viruses to maintain the stability of their transcripts is described below.
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Affiliation(s)
- Stephanie L Moon
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, United States
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496
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Pittella F, Miyata K, Maeda Y, Suma T, Watanabe S, Chen Q, Christie RJ, Osada K, Nishiyama N, Kataoka K. Pancreatic cancer therapy by systemic administration of VEGF siRNA contained in calcium phosphate/charge-conversional polymer hybrid nanoparticles. J Control Release 2012; 161:868-74. [PMID: 22580114 DOI: 10.1016/j.jconrel.2012.05.005] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 04/18/2012] [Accepted: 05/01/2012] [Indexed: 01/06/2023]
Abstract
Development of an efficient in vivo delivery vehicle of small interfering RNA (siRNA) is the key challenge for successful siRNA-based therapies. In this study, toward systemic delivery of siRNA to solid tumors, a smart polymer/calcium phosphate (CaP)/siRNA hybrid nanoparticle was prepared to feature biocompatibility, reversible stability and endosomal escape functionality using a pH sensitive block copolymer of poly(ethylene glycol) and charge-conversional polymer (PEG-CCP), of which anionic functional groups could be converted to cationic groups in an endosomal acidic condition for facilitated endosomal escape. Nanoparticles were confirmed to be approximately 100nm in size, narrowly dispersed and spherical. Also, the nanoparticle was highly tolerable in medium containing serum, while releasing the entrapped siRNA in a cytoplasm-mimicking ionic condition, presumably based on the equilibrium between CaP complexes and calcium ions. Further, the nanoparticle showed high gene silencing efficiency in cultured pancreatic cancer cells (BxPC3) without associated cytotoxicity. Ultimately, systemic administration of the nanoparticles carrying vascular endothelium growth factor (VEGF) siRNA led to the significant reduction in the subcutaneous BxPC3 tumor growth, well consistent with the enhanced accumulation of siRNA and the significant VEGF gene silencing (~68%) in the tumor. Thus, the hybrid nanoparticle was demonstrated to be a promising formulation toward siRNA-based cancer therapies.
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Affiliation(s)
- Frederico Pittella
- Division of Clinical Biotechnology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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497
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Hayashi Y, Mori Y, Yamashita S, Motoyama K, Higashi T, Jono H, Ando Y, Arima H. Potential Use of Lactosylated Dendrimer (G3)/α-Cyclodextrin Conjugates as Hepatocyte-Specific siRNA Carriers for the Treatment of Familial Amyloidotic Polyneuropathy. Mol Pharm 2012; 9:1645-53. [DOI: 10.1021/mp200654g] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Yuya Hayashi
- Department of Physical Pharmaceutics,
Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1
Oe-honmachi, Kumamoto 862-0973, Japan
| | - Yoshimasa Mori
- Department of Physical Pharmaceutics,
Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1
Oe-honmachi, Kumamoto 862-0973, Japan
| | - Shogo Yamashita
- Department of Physical Pharmaceutics,
Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1
Oe-honmachi, Kumamoto 862-0973, Japan
| | - Keiichi Motoyama
- Department of Physical Pharmaceutics,
Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1
Oe-honmachi, Kumamoto 862-0973, Japan
| | - Taishi Higashi
- Department of Physical Pharmaceutics,
Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1
Oe-honmachi, Kumamoto 862-0973, Japan
| | - Hirofumi Jono
- Department of Diagnostic Medicine,
Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo,
Kumamoto 860-8556, Japan
| | - Yukio Ando
- Department of Diagnostic Medicine,
Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo,
Kumamoto 860-8556, Japan
| | - Hidetoshi Arima
- Department of Physical Pharmaceutics,
Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1
Oe-honmachi, Kumamoto 862-0973, Japan
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498
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Inhibition of adenovirus multiplication by short interfering RNAs directly or indirectly targeting the viral DNA replication machinery. Antiviral Res 2012; 94:195-207. [PMID: 22510340 PMCID: PMC3370646 DOI: 10.1016/j.antiviral.2012.03.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2011] [Revised: 03/23/2012] [Accepted: 03/28/2012] [Indexed: 01/19/2023]
Abstract
Human adenoviruses are a common threat to immunocompromised patients, e.g., HIV-positive individuals or solid-organ and, in particular, allogeneic stem cell transplant recipients. Antiviral drugs have a limited effect on adenoviruses, and existing treatment modalities often fail to prevent fatal outcome. Silencing of viral genes by short interfering RNAs (siRNAs) holds a great promise in the treatment of viral infections. The aim of the present study was to identify adenoviral candidate targets for RNA interference-mediated inhibition of adenoviral replication. We investigated the impact of silencing of a set of early, middle, and late viral genes on the replication of adenovirus 5 in vitro. Adenovirus replication was inhibited by siRNAs directed against the adenoviral E1A, DNA polymerase, preterminal protein (pTP), IVa2, hexon, and protease genes. Silencing of early and middle genes was more effective in inhibiting adenovirus multiplication than was silencing of late genes. A siRNA directed against the viral DNA polymerase mRNA decreased viral genome copy numbers and infectious virus progeny by several orders of magnitude. Since silencing of any of the early genes directly or indirectly affected viral DNA synthesis, our data suggest that reducing viral genome copy numbers is a more promising strategy for the treatment of adenoviral infections than is reducing the numbers of proteins necessary for capsid generation. Thus, adenoviral DNA replication was identified as a key target for RNAi-mediated inhibition of adenovirus multiplication. In addition, the E1A transcripts emerged as a second important target, because its knockdown markedly improved the viability of cells at late stages of infection.
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499
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Krell J, Frampton AE, Jacob J, Castellano L, Stebbing J. miRNAs in breast cancer: ready for real time? Pharmacogenomics 2012; 13:709-19. [PMID: 22515613 DOI: 10.2217/pgs.12.15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Over the past decade, major advances in our comprehension of breast cancer biology have led to improved diagnostic and prognostic techniques and the development of novel targeted therapies. However, the efficacy of new treatments remains limited by a combination of drug toxicity, resistance and persisting insufficiencies in our understanding of tumor-signaling pathways; furthermore, the reliability of identified biomarkers is contentious. Following their recent discovery, miRNAs have been established as critical regulators of gene expression, and their putative roles as oncogenes and tumor-suppressor genes has provided a potential new dimension to our clinical approach to breast cancer diagnosis and treatment. Their role as biomarkers and therapeutic targets is appealing; however, several barriers have limited our ability to translate this potential into a clinical reality. This review focuses on the currently accepted roles of miRNAs in breast cancer pathogenesis, and highlights the clinical challenges and breakthroughs in this field to date.
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Affiliation(s)
- Jonathan Krell
- Department of Surgery & Cancer, Imperial College, Hammersmith Hospital, Du Cane Road, London, W12 ONN, UK.
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500
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Ashley CE, Carnes EC, Epler KE, Padilla DP, Phillips GK, Castillo RE, Wilkinson DC, Wilkinson BS, Burgard CA, Kalinich RM, Townson JL, Chackerian B, Willman CL, Peabody DS, Wharton W, Brinker CJ. Delivery of small interfering RNA by peptide-targeted mesoporous silica nanoparticle-supported lipid bilayers. ACS NANO 2012; 6:2174-88. [PMID: 22309035 PMCID: PMC3332089 DOI: 10.1021/nn204102q] [Citation(s) in RCA: 156] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The therapeutic potential of small interfering RNAs (siRNAs) is severely limited by the availability of delivery platforms that protect siRNA from degradation, deliver it to the target cell with high specificity and efficiency, and promote its endosomal escape and cytosolic dispersion. Here we report that mesoporous silica nanoparticle-supported lipid bilayers (or "protocells") exhibit multiple properties that overcome many of the limitations of existing delivery platforms. Protocells have a 10- to 100-fold greater capacity for siRNA than corresponding lipid nanoparticles and are markedly more stable when incubated under physiological conditions. Protocells loaded with a cocktail of siRNAs bind to cells in a manner dependent on the presence of an appropriate targeting peptide and, through an endocytic pathway followed by endosomal disruption, promote delivery of the silencing nucleotides to the cytoplasm. The expression of each of the genes targeted by the siRNAs was shown to be repressed at the protein level, resulting in a potent induction of growth arrest and apoptosis. Incubation of control cells that lack expression of the antigen recognized by the targeting peptide with siRNA-loaded protocells induced neither repression of protein expression nor apoptosis, indicating the precise specificity of cytotoxic activity. In terms of loading capacity, targeting capabilities, and potency of action, protocells provide unique attributes as a delivery platform for therapeutic oligonucleotides.
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Affiliation(s)
- Carlee E Ashley
- Biotechnology and Bioengineering Department, Sandia National Laboratories, Livermore, California 94551-0969, USA. or
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