201
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Thomas T, Ginsberg H. Development of apolipoprotein B antisense molecules as a therapy for hyperlipidemia. Curr Atheroscler Rep 2010; 12:58-65. [PMID: 20425272 DOI: 10.1007/s11883-009-0078-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
As new studies demonstrate that lower levels of low-density lipoprotein cholesterol (LDL-C) reduce cardiovascular disease, and as goals for LDL-C in high-risk individuals are reduced further and further, reaching those goals becomes more difficult for a significant percentage of the population. New therapeutic approaches to lower LDL-C would, therefore, be advantageous, particularly in those who are most likely to suffer cardiovascular disease-associated morbidity and mortality. Mouse and human genetic models suggest that decreasing hepatic apolipoprotein B (apoB) production may be a therapeutic approach for the treatment of dyslipidemia. Because antisense oligonucleotides naturally distribute to the liver and can specifically inhibit synthesis of proteins from their messenger RNAs, antisense oligonucleotides represent a potential approach for decreasing the biosynthesis of apoB, and thereby, the production of both very low density lipoprotein (VLDL) and LDL. Newly developed apoB antisense approaches have produced results in animal models and humans, providing proof of concept regarding reductions in LDL-C concentrations. Surprisingly, despite prior experience with inhibitors of microsomal triglyceride transfer protein, which also inhibits the secretion of VLDL, apoB antisense-mediated reduction in VLDL secretion does not appear to cause marked steatosis. The mechanisms whereby two different approaches for inhibiting apoB and triglyceride secretion have different effects on hepatic triglycerides are currently being examined.
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Affiliation(s)
- Tiffany Thomas
- Columbia University, 622 West 168th Street, PH10-305, New York, NY 10032, USA.
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202
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Singh N, Agrawal A, Leung AKL, Sharp PA, Bhatia SN. Effect of nanoparticle conjugation on gene silencing by RNA interference. J Am Chem Soc 2010; 132:8241-3. [PMID: 20518524 PMCID: PMC2968757 DOI: 10.1021/ja102132e] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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RNA interference (RNAi) is a cellular process whereby the silencing of a particular gene is mediated by short RNAs (siRNAs). Although siRNAs have great therapeutic potential, cellular delivery has been a challenge. Nanoparticle-siRNA conjugates have emerged as potential delivery vehicles; however, reports describing the effects of nanoparticle conjugation on RISC incorporation and subsequent gene silencing have been mixed. In this report, we have systematically evaluated the effect of siRNA coupling strategies using a model nanoparticle system with varying conjugation schemes. We show that the accessibility of the siRNA linked to the nanoparticle and the lability of the cross-linker are critical for efficient gene knockdown.
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Affiliation(s)
- Neetu Singh
- Harvard-MIT Division of Health Sciences and Technology, MIT, Cambridge, Massachusetts 02139, USA
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203
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Querbes W, Ge P, Zhang W, Fan Y, Costigan J, Charisse K, Maier M, Nechev L, Manoharan M, Kotelianski V, Sah DWY. Direct CNS delivery of siRNA mediates robust silencing in oligodendrocytes. Oligonucleotides 2010; 19:23-29. [PMID: 19093781 DOI: 10.1089/oli.2008.0165] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The most significant challenge remaining in the development of small interfering RNAs (siRNAs) as a new class of therapeutic drugs is successful delivery in vivo. The majority of reported studies describing delivery of siRNA or short hairpin RNA (shRNA) to the central nervous system (CNS) have focused on RNA interference (RNAi) in neurons. Here we show direct CNS delivery of siRNA to a different cell type-oligodendrocytes-using convection-enhanced delivery, and demonstrate robust silencing of an endogenous oligodendrocyte-specific gene, 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) with siRNA formulated in saline. The silencing is not sequence-dependent as several different siRNAs are effective in inhibiting target gene expression. Furthermore, we show that CNPase mRNA reduction is dose-dependent, durable for up to 1 week, and mediated by an RNAi mechanism. Increasing the flow rate of siRNA infusion increased the distribution of mRNA suppression to encompass white matter regions distant from the infusion site. Finally, we demonstrate suppression of CNPase mRNA in the nonhuman primate CNS. Taken together, these results show for the first time robust RNAi within oligodendrocytes in vivo and demonstrate the important potential of siRNAs in the treatment of CNS disorders involving oligodendrocyte pathology.
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Affiliation(s)
- William Querbes
- Alnylam Pharmaceuticals, Inc., Cambridge, Massachusetts 02142, USA.
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204
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Berger KL, Randall G. Possibilities for RNA interference in developing hepatitis C virus therapeutics. Viruses 2010; 2:1647-1665. [PMID: 21994699 PMCID: PMC3185727 DOI: 10.3390/v2081647] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 08/04/2010] [Accepted: 08/04/2010] [Indexed: 12/13/2022] Open
Abstract
The discovery and characterization of the RNA interference (RNAi) pathway has been one of the most important scientific developments of the last 12 years. RNAi is a cellular pathway wherein small RNAs control the expression of genes by either degrading homologous RNAs or preventing the translation of RNAs with partial homology. It has impacted basic biology on two major fronts. The first is the discovery of microRNAs (miRNAs), which regulate almost every cellular process and are required for some viral infections, including hepatitis C virus (HCV). The second front is the use of small interfering RNAs (siRNAs) as the first robust tool for mammalian cellular genetics. This has led to the identification of hundreds of cellular genes that are important for HCV infection. There is now a major push to adapt RNAi technology to the clinic. In this review, we explore the impact of RNAi in understanding HCV biology, the progress in design of RNAi-based therapeutics for HCV, and remaining obstacles.
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Affiliation(s)
| | - Glenn Randall
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-773-702-5673; Fax: +1-773-834-8150
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205
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Hufbauer M, Lazić D, Akgül B, Brandsma J, Pfister H, Weissenborn S. Enhanced human papillomavirus type 8 oncogene expression levels are crucial for skin tumorigenesis in transgenic mice. Virology 2010; 403:128-36. [DOI: 10.1016/j.virol.2010.04.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Revised: 03/01/2010] [Accepted: 04/14/2010] [Indexed: 12/25/2022]
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206
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Peer D. Induction of therapeutic gene silencing in leukocyte-implicated diseases by targeted and stabilized nanoparticles: a mini-review. J Control Release 2010; 148:63-68. [PMID: 20624432 DOI: 10.1016/j.jconrel.2010.06.029] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2010] [Revised: 06/25/2010] [Accepted: 06/29/2010] [Indexed: 10/19/2022]
Abstract
RNA interference (RNAi) is a highly conserved endogenous mechanism that uses small RNA species to guide the sequence-specific silencing of gene expression. The discovery that RNAi functions in mammalian cells to regulate important cellular processes suggested that harnessing these endogenous gene-silencing pathways can prove to be an effective method for the targeted silencing of gene expression. Yet, the key challenge in translating the discovery of RNAi into a novel therapeutic modality is the lack of effective and safe delivery strategies. Here, we describe the major systemic delivery platforms that have been developed. Focus is given to the development of new strategies to target leukocytes, which are among the most difficult cells to transduce with RNAi. Finally, we discuss our strategies to target subsets of leukocytes using integrin-targeted and stabilized nanoparticles (I-tsNPs).
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Affiliation(s)
- Dan Peer
- Laboratory of Nanomedicine, Dept. of Cell Research and Immunology, George S. Wise Faculty of Life Science, Israel; Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv University, Tel Aviv, 69978, Israel.
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207
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Straarup EM, Fisker N, Hedtjärn M, Lindholm MW, Rosenbohm C, Aarup V, Hansen HF, Ørum H, Hansen JBR, Koch T. Short locked nucleic acid antisense oligonucleotides potently reduce apolipoprotein B mRNA and serum cholesterol in mice and non-human primates. Nucleic Acids Res 2010; 38:7100-11. [PMID: 20615897 PMCID: PMC2978335 DOI: 10.1093/nar/gkq457] [Citation(s) in RCA: 194] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The potency and specificity of locked nucleic acid (LNA) antisense oligonucleotides was investigated as a function of length and affinity. The oligonucleotides were designed to target apolipoprotein B (apoB) and were investigated both in vitro and in vivo. The high affinity of LNA enabled the design of short antisense oligonucleotides (12- to 13-mers) that possessed high affinity and increased potency both in vitro and in vivo compared to longer oligonucleotides. The short LNA oligonucleotides were more target specific, and they exhibited the same biodistribution and tissue half-life as longer oligonucleotides. Pharmacology studies in both mice and non-human primates were conducted with a 13-mer LNA oligonucleotide against apoB, and the data showed that repeated dosing of the 13-mer at 1-2 mg/kg/week was sufficient to provide a significant and long lasting lowering of non-high-density lipoprotein (non-HDL) cholesterol without increasing serum liver toxicity markers. The data presented here show that oligonucleotide length as a parameter needs to be considered in the design of antisense oligonucleotide and that potent short oligonucleotides with sufficient target affinity can be generated using the LNA chemistry. Conclusively, we present a 13-mer LNA oligonucleotide with therapeutic potential that produce beneficial cholesterol lowering effect in non-human primates.
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208
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Weinstein S, Peer D. RNAi nanomedicines: challenges and opportunities within the immune system. NANOTECHNOLOGY 2010; 21:232001. [PMID: 20463388 DOI: 10.1088/0957-4484/21/23/232001] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
RNAi, as a novel therapeutic modality, has an enormous potential to bring the era of personalized medicine one step further from notion into reality. However, delivery of RNAi effector molecules into their target tissues and cells remain extremely challenging. Major attempts have been made in recent years to develop sophisticated nanocarriers that could overcome these hurdles. This review will present the recent progress with the challenges and opportunities in this emerging field, focusing mostly on the in vivo applications with special emphasis on the strategies for RNAi delivery into immune cells.
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Affiliation(s)
- Shiri Weinstein
- Department of Cell Research and Immunology, George S Wise Faculty of Life Science, Israel
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209
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Shukla S, Sumaria CS, Pradeepkumar PI. Exploring chemical modifications for siRNA therapeutics: a structural and functional outlook. ChemMedChem 2010; 5:328-49. [PMID: 20043313 DOI: 10.1002/cmdc.200900444] [Citation(s) in RCA: 156] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
RNA interference (RNAi) is a post-transcriptional gene silencing mechanism induced by small interfering RNAs (siRNAs) and micro-RNAs (miRNAs), and has proved to be one of the most important scientific discoveries made in the last century. The robustness of RNAi has opened up new avenues in the development of siRNAs as therapeutic agents against various diseases including cancer and HIV. However, there had remained a lack of a clear mechanistic understanding of messenger RNA (mRNA) cleavage mediated by Argonaute2 of the RNA-induced silencing complex (RISC), due to inadequate structural data. The X-ray crystal structures of the Argonaute (Ago)-DNA-RNA complexes reported recently have proven to be a breakthrough in this field, and the structural details can provide guidelines for the design of the next generation of siRNA therapeutics. To harness siRNAs as therapeutic agents, the prudent use of various chemical modifications is warranted to enhance nuclease resistance, prevent immune activation, decrease off-target effects, and to improve pharmacokinetic and pharmacodynamic properties. The focus of this review is to interpret the tolerance of various chemical modifications employed in siRNAs toward RNAi by taking into account the crystal structures and biochemical studies of Ago-RNA complexes. Moreover, the challenges and recent progress in imparting druglike properties to siRNAs along with their delivery strategies are discussed.
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Affiliation(s)
- Siddharth Shukla
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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210
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Cuestas ML, Mathet VL, Oubiña JR, Sosnik A. Drug delivery systems and liver targeting for the improved pharmacotherapy of the hepatitis B virus (HBV) infection. Pharm Res 2010; 27:1184-202. [PMID: 20333454 DOI: 10.1007/s11095-010-0112-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Accepted: 03/01/2010] [Indexed: 12/17/2022]
Abstract
In spite of the progress made in vaccine and antiviral therapy development, hepatitis B virus (HBV) infection is still the most common cause of liver cirrhosis and hepatocellular carcinoma, with more than 400 million people chronically infected worldwide. Antiviral therapy with nucleos(t)ide analogues and/or immunomodulating peptides is the only option to control and prevent the progression of the disease in chronic hepatitis B (CHB)-infected patients. So far, the current antiviral monotherapy remains unsatisfactory because of the low efficacy and the development of drug resistance mutants. Moreover, viral rebound is frequently observed following therapy cessation, since covalent closed circular DNA (cccDNA) is not removed from hepatocytes by antiviral therapy. First, this review describes the current pharmacotherapy for the management of CHB and the new drug candidates being investigated. Then, the challenges in the development of drug delivery systems for the targeting of antiviral drugs to the liver parenchyma are discussed. Finally, perspectives in the design of a more efficient pharmacotherapy to eradicate the virus from the host are addressed.
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Affiliation(s)
- María L Cuestas
- Centro para el Estudio de Hepatitis Virales, Departamento de Microbiología, Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, Piso 11 (1121), Buenos Aires, Argentina
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211
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Jung S, Lee SH, Mok H, Chung HJ, Park TG. Gene silencing efficiency of siRNA-PEG conjugates: effect of PEGylation site and PEG molecular weight. J Control Release 2010; 144:306-13. [PMID: 20206653 DOI: 10.1016/j.jconrel.2010.03.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 02/22/2010] [Accepted: 03/01/2010] [Indexed: 11/25/2022]
Abstract
Small interfering RNA (siRNA) was conjugated with poly(ethylene glycol) (PEG) at four different terminal ends (sense 3', sense 5', antisense 3', and antisense 5') via cleavable disulfide and noncleavable thioether linkages to evaluate their gene silencing efficiencies upon complexation with Lipofectamine2000. The PEGylation site at the four siRNA termini and PEG molecular weight were not critical factors to significantly affect gene silencing activities. Cleavable siRNA-PEG conjugates showed comparable gene silencing activities to naked siRNA, and exhibited sequence-specific degradation of a target mRNA. Interestingly, noncleavable siRNA-PEG conjugates were processed by Dicer, enabling to exert RNAi effect without showing a target sequence-specific manner. However, only cleavable siRNA-PEG conjugates significantly reduced the extent of INF-alpha release as compared to noncleavable siRNA-PEG conjugates, suggesting that they can be potentially used for therapeutic siRNA applications.
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Affiliation(s)
- Sooyeon Jung
- Department of Biological Sciences and Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology, Daejeon 305-701, South Korea
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212
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Abstract
RNA interference (RNAi) is a collection of small RNA directed mechanisms that result in sequence specific inhibition of gene expression. The notion that RNAi could lead to a new class of therapeutics caught the attention of many investigators soon after its discovery. The field of applied RNAi therapeutics has moved very quickly from lab to bedside. The RNAi approach has been widely used for drug development and several phase I and II clinical trials are under way. However, there are still some concerns and challenges to overcome for therapeutic applications. These include the potential for off-target effects, triggering innate immune responses and most importantly obtaining specific delivery into the cytoplasm of target cells. This review focuses on the current status of RNAi-based therapeutics, the challenges it faces and how to overcome them.
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Affiliation(s)
- Katrin Tiemann
- Department of Molecular Biology, Beckman Research Institute of the City of Hope, Duarte, CA, USA
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213
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Affiliation(s)
- Huricha Baigude
- Program for RNA Biology, Sanford Children's Health Research Center, Burnham Institute for Medical Research, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
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214
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Chen Q, Butler D, Querbes W, Pandey RK, Ge P, Maier MA, Zhang L, Rajeev KG, Nechev L, Kotelianski V, Manoharan M, Sah DWY. Lipophilic siRNAs mediate efficient gene silencing in oligodendrocytes with direct CNS delivery. J Control Release 2010; 144:227-32. [PMID: 20170694 DOI: 10.1016/j.jconrel.2010.02.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2009] [Revised: 01/29/2010] [Accepted: 02/04/2010] [Indexed: 10/19/2022]
Abstract
Conjugation of small interfering RNA (siRNA) with lipophilic molecules has been demonstrated to enhance cellular uptake in cell culture and to produce efficient endogenous gene silencing in the liver after systemic administration and in neurons after direct local injection. Here, we evaluated the in vivo delivery of siRNAs conjugated with different linkers to cholesterol by targeting CNPase (2'-3'-cyclic nucleotide 3'-phosphodiesterase) in oligodendrocytes. Cholesterol-conjugated siRNAs administered to the rat corpus callosum by intraparenchymal central nervous system (CNS) infusion show improved silencing ability compared with unconjugated siRNA. Furthermore, conjugation of siRNA to cholesterol with a cleavable disulfide linker appears to be beneficial for improving the potency of silencing of CNPase mRNA in oligodendrocytes in vivo. Taken together, these findings indicate that cholesterol-conjugated siRNAs are effective for direct CNS delivery to oligodendrocytes, and that the biocleavable disulfide linker appears to be beneficial for improving the potency of silencing of target mRNA in vivo.
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Affiliation(s)
- Qingmin Chen
- Alnylam Pharmaceuticals Inc., 300 Third Street, Cambridge, MA 02142, USA.
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215
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Zhou J, Rossi JJ. Aptamer-targeted cell-specific RNA interference. SILENCE 2010; 1:4. [PMID: 20226078 PMCID: PMC2835998 DOI: 10.1186/1758-907x-1-4] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Accepted: 02/01/2010] [Indexed: 11/10/2022]
Abstract
This potent ability of small interfering (si)RNAs to inhibit the expression of complementary RNA transcripts is being exploited as a new class of therapeutics for a variety of diseases. However, the efficient and safe delivery of siRNAs into specific cell populations is still the principal challenge in the clinical development of RNAi therapeutics. With the increasing enthusiasm for developing targeted delivery vehicles, nucleic acid-based aptamers targeting cell surface proteins are being explored as promising delivery vehicles to target a distinct disease or tissue in a cell-type-specific manner. The aptamer-based delivery of siRNAs can often enhance the therapeutic efficacy and reduce the unwanted off-target effects of siRNAs. In particular, for RNA interference-based therapeutics, aptamers represent an efficient agent for cell type-specific, systemic delivery of these oligonucleotides. In this review, we summarize recent attractive developments in creatively using cell-internalizing aptamers to deliver siRNAs to target cells. The optimization and improvement of aptamer-targeted siRNAs for clinical translation are further highlighted.
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Affiliation(s)
- Jiehua Zhou
- Division of Molecular and Cellular Biology, Beckman Research Institute of City of Hope, City of Hope, Duarte, CA 91010, USA.
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216
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Ge Q, Dallas A, Ilves H, Shorenstein J, Behlke MA, Johnston BH. Effects of chemical modification on the potency, serum stability, and immunostimulatory properties of short shRNAs. RNA (NEW YORK, N.Y.) 2010; 16:118-30. [PMID: 19948766 PMCID: PMC2802022 DOI: 10.1261/rna.1901810] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Accepted: 10/16/2009] [Indexed: 05/23/2023]
Abstract
Small hairpin RNAs (shRNAs) with 19-base-pair, or shorter, stems (short shRNAs [sshRNAs]) have been found to constitute a class whose mechanism of action appears to be distinct from that of small interfering RNAs (siRNAs) or longer shRNAs. These sshRNAs can be as active as canonical siRNAs or longer shRNAs. Their activity is affected by whether the antisense strand is positioned 5' or 3' to the loop (L or R sshRNAs, respectively). Dicer seems not to be involved in the processing of sshRNAs, although the mechanism of target gene suppression by these hairpins is through Ago2-mediated mRNA cleavage. In this study, the effects of chemical modifications on the potency, serum stability, and innate immune response of sshRNAs were investigated. Deoxynucleotide substitution and 2'-O-methyl (2'-OMe) modification in the sense strand and loop did not affect silencing activity, but, unlike with siRNAs, when placed in the antisense strand these modifications were detrimental. Conjugation with bulky groups at the 5'-end of L sshRNAs or 3'-end of R sshRNAs had a negative impact on the potency. Unmodified sshRNAs in dimer form or with blunt ends were immunostimulatory. Some modifications such as 3'-end conjugation and phosphorothioate linkages on the backbone of the sshRNAs could also induce inflammatory cytokine production. However, 2'-OMe substitution of sshRNAs abrogated the innate immune response and improved the serum stability of the hairpins.
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Affiliation(s)
- Qing Ge
- SomaGenics, Inc., Santa Cruz, California 95060, USA.
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217
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López-Fraga M, Martínez T, Jiménez A. RNA interference technologies and therapeutics: from basic research to products. BioDrugs 2009; 23:305-32. [PMID: 19754220 PMCID: PMC7099360 DOI: 10.2165/11318190-000000000-00000] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
RNA interference (RNAi) is a natural cellular process that regulates gene expression by a highly precise mechanism of sequence-directed gene silencing at the stage of translation by degrading specific messenger RNAs or blocking translation. In recent years, the use of RNAi for therapeutic applications has gained considerable momentum. It has been suggested that most of the novel disease-associated targets that have been identified are not ‘druggable’ with conventional approaches. However, any disease-causing gene and any cell type or tissue can potentially be targeted with RNAi. This review focuses on the current knowledge of RNAi mechanisms and the safety issues associated with its potential use in a therapeutic setting. Some of the most important aspects to consider when working towards the application of RNAi-based products in a clinical setting have been related to achieving high efficacies and enhanced stability profiles through a careful design of the nucleic acid sequence and the introduction of chemical modifications, but most of all, to developing improved delivery systems, both viral and non-viral. These new delivery systems allow for these products to reach the desired target cells, tissues or organs in a highly specific manner and after administration of the lowest possible doses. Various routes of application and target locations are currently being addressed in order to develop effective delivery systems for different targets and pathologies, including infectious pathologies, genetic pathologies and diseases associated with dysregulation of endogenous microRNAs. As with any new technology, several challenges and important aspects to be considered have risen on the road to clinical intervention, e.g. correct design of preclinical toxicology studies, regulatory concerns, and intellectual property protection. The main advantages related to the use of RNAi-based products in a clinical setting, and the latest clinical and preclinical studies using these compounds, are reviewed.
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218
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Abstract
RNA interference (RNAi) is the process of sequence-specific, post-tanscriptional gene silencing, initiated by double-stranded RNA (dsRNA). The gene therapy for familial ALS with siRNA had been started and showed promising results in the model mouse. There is a recent progress in the delivery of siRNA to the central nervous system. There are still important problems for application of gene therapy including off-target effect and gene delivery of siRNA, but a rapid progress can be expected because of the extremely high efficiency of siRNA.
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Affiliation(s)
- Takanori Yokota
- Department of Neurology and Neurological Science, Tokyo Medical and Dental University
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219
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Juliano R, Bauman J, Kang H, Ming X. Biological barriers to therapy with antisense and siRNA oligonucleotides. Mol Pharm 2009; 6:686-95. [PMID: 19397332 DOI: 10.1021/mp900093r] [Citation(s) in RCA: 208] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Attaining the full therapeutic utility of antisense and siRNA oligonucleotides will require understanding of the biological barriers that stand between initial administration of these drugs and their final actions within cells. This review examines some of the key barriers that affect the biodistribution of oligonucleotides both in molecular form and when they are associated with nanocarriers. An understanding of the biological processes underlying these barriers will aid in the design of more effective delivery systems.
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Affiliation(s)
- R Juliano
- UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
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220
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Li J, Liang Z. The consideration of synthetic short interfering RNA for therapeutic use. Basic Clin Pharmacol Toxicol 2009; 106:22-9. [PMID: 19663819 DOI: 10.1111/j.1742-7843.2009.00464.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Small RNA molecules can act as regulators of post-transcriptional gene silencing and can target any given protein via the RNA interference pathway. This leads to the high expectation of small interference RNA (siRNA) as a therapeutic platform. Many companies and organisations are active in this development, which consequently forces siRNA's pharmacokinetic studies because pharmacokinetics plays an important role in elucidating the pharmacodynamic and toxicological mechanism of test articles. In particular, pharmacokinetics is mandatory in investigational new drug application in many countries. Some pre-clinical and clinical pharmacokinetic results have already been published and the fate of siRNA compounds in biological matrices has been explored in depth. The elucidation of the siRNA's metabolism improves the rational design of siRNA for disease control. This review focuses on the study of synthetic siRNA pharmacokinetics, the challenges of siRNA as a therapeutic agent and the strategies involved for improving siRNA bioavailability from the view of siRNA metabolism.
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Affiliation(s)
- Jun Li
- Laboratory of Nucleic Acid Technology, Institute of Molecular Medicine, PKU, Beijing, China.
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221
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Li L, Shen Y. Overcoming obstacles to develop effective and safe siRNA therapeutics. Expert Opin Biol Ther 2009; 9:609-19. [DOI: 10.1517/14712590902911420] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Leiming Li
- siRNA Therapeutics, Abbott Laboratories, 100 Abbott Park Road, Abbott Park, IL 60031, USA
| | - Yu Shen
- siRNA Therapeutics, Abbott Laboratories, 100 Abbott Park Road, Abbott Park, IL 60031, USA
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222
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Weinberg MS, Wood MJA. Short non-coding RNA biology and neurodegenerative disorders: novel disease targets and therapeutics. Hum Mol Genet 2009; 18:R27-39. [PMID: 19297399 DOI: 10.1093/hmg/ddp070] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Genomic studies in model organisms and in humans have shown that complexity in biological systems arises not from the absolute number of genes, but from the differential use of combinations of genetic programmes and the myriad ways in which these are regulated spatially and temporally during development, senescence and in disease. Nowhere is this lesson in biological complexity likely to be more apparent than in the human nervous system. Increasingly, the role of genomic non-protein coding small regulatory RNAs, in particular the microRNAs (miRNAs), in regulating cellular pathways controlling fundamental functions in the nervous system and in neurodegenerative disease is being appreciated. Not only might dysregulated expression of miRNAs serve as potential disease biomarkers but increasingly such short regulatory RNAs are being implicated directly in the pathogenesis of complex, sporadic neurodegenerative disease. Moreover, the targeting and exploitation of short RNA silencing pathways, commonly known as RNA interference, and the development of related tools, offers novel therapeutic approaches to target upstream disease components with the promise of providing future disease modifying therapies for neurodegenerative disorders.
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Affiliation(s)
- Marc S Weinberg
- Department of Molecular Medicine and Haematology, University of the Witwatersrand Medical School, Parktown, South Africa
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223
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Yu B, Zhao X, Lee LJ, Lee RJ. Targeted delivery systems for oligonucleotide therapeutics. AAPS JOURNAL 2009; 11:195-203. [PMID: 19296227 DOI: 10.1208/s12248-009-9096-1] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Accepted: 02/20/2009] [Indexed: 12/11/2022]
Abstract
Oligonucleotides including antisense oligonucleotides and siRNA are emerging as promising therapeutic agents against a variety of diseases. Effective delivery of these molecules is critical to their successful clinical application. Targeted systems can greatly improve the efficiency and specificity of oligonucleotides delivery. Meanwhile, an effective delivery system must successfully overcome a multitude of biological barriers to enable the oligonucleotides to reach the site of action and access their biological targets. Several delivery strategies based on different platform technologies and different targeting ligands have been developed to achieve these objectives. This review aims at providing a summary and perspective on recent progress in this very active area of research.
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Affiliation(s)
- Bo Yu
- Department of Chemical and Biomolecular Engineering, College of Pharmacy, The Ohio State University, Columbus, Ohio, USA
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224
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Abstract
Well over a hundred reports have been published describing use of synthetic small-interfering RNAs (siRNAs) in animals. The majority of these reports employed unmodified RNA duplexes. While unmodified RNA is the natural effector molecule of RNA interference, certain problems arise with experimental or therapeutic use of RNA duplexes in vivo, some of which can be improved or solved through use of chemical modifications. Judicious use of chemical modifications can improve the nuclease stability of an RNA duplex, decrease the likelihood of triggering an innate immune response, lower the incidence of off-target effects (OTEs), and improve pharmacodynamics. This review will examine studies that document the utility of various chemical modifications for use in siRNAs, both in vitro and in vivo, with close attention given to reports demonstrating actual performance in animal model systems.
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Affiliation(s)
- Mark A Behlke
- Integrated DNA Technologies, Inc., Coralville, Iowa 52241, USA.
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225
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Carmona S, Jorgensen MR, Kolli S, Crowther C, Salazar FH, Marion PL, Fujino M, Natori Y, Thanou M, Arbuthnot P, Miller AD. Controlling HBV Replication in Vivo by Intravenous Administration of Triggered PEGylated siRNA-Nanoparticles. Mol Pharm 2009; 6:706-17. [DOI: 10.1021/mp800157x] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Sergio Carmona
- Antiviral Gene Therapy Research Unit, Department of Molecular Medicine and Haematology, University of the Witwatersrand Medical School, Private Bag 3, WITS 2050, South Africa, Imperial College Genetic Therapies Centre, Department of Chemistry, Flowers Building, Armstrong Road, Imperial College London, London SW7 2AZ, U.K., Stanford University, Stanford, California, Hepadnavirus Testing, Inc., Mountain View, California, RNAi Co., Cosmos Hongo Bldg. 10F, 4-1-4, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan, and
| | - Michael R. Jorgensen
- Antiviral Gene Therapy Research Unit, Department of Molecular Medicine and Haematology, University of the Witwatersrand Medical School, Private Bag 3, WITS 2050, South Africa, Imperial College Genetic Therapies Centre, Department of Chemistry, Flowers Building, Armstrong Road, Imperial College London, London SW7 2AZ, U.K., Stanford University, Stanford, California, Hepadnavirus Testing, Inc., Mountain View, California, RNAi Co., Cosmos Hongo Bldg. 10F, 4-1-4, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan, and
| | - Soumia Kolli
- Antiviral Gene Therapy Research Unit, Department of Molecular Medicine and Haematology, University of the Witwatersrand Medical School, Private Bag 3, WITS 2050, South Africa, Imperial College Genetic Therapies Centre, Department of Chemistry, Flowers Building, Armstrong Road, Imperial College London, London SW7 2AZ, U.K., Stanford University, Stanford, California, Hepadnavirus Testing, Inc., Mountain View, California, RNAi Co., Cosmos Hongo Bldg. 10F, 4-1-4, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan, and
| | - Carol Crowther
- Antiviral Gene Therapy Research Unit, Department of Molecular Medicine and Haematology, University of the Witwatersrand Medical School, Private Bag 3, WITS 2050, South Africa, Imperial College Genetic Therapies Centre, Department of Chemistry, Flowers Building, Armstrong Road, Imperial College London, London SW7 2AZ, U.K., Stanford University, Stanford, California, Hepadnavirus Testing, Inc., Mountain View, California, RNAi Co., Cosmos Hongo Bldg. 10F, 4-1-4, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan, and
| | - Felix H. Salazar
- Antiviral Gene Therapy Research Unit, Department of Molecular Medicine and Haematology, University of the Witwatersrand Medical School, Private Bag 3, WITS 2050, South Africa, Imperial College Genetic Therapies Centre, Department of Chemistry, Flowers Building, Armstrong Road, Imperial College London, London SW7 2AZ, U.K., Stanford University, Stanford, California, Hepadnavirus Testing, Inc., Mountain View, California, RNAi Co., Cosmos Hongo Bldg. 10F, 4-1-4, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan, and
| | - Patricia L. Marion
- Antiviral Gene Therapy Research Unit, Department of Molecular Medicine and Haematology, University of the Witwatersrand Medical School, Private Bag 3, WITS 2050, South Africa, Imperial College Genetic Therapies Centre, Department of Chemistry, Flowers Building, Armstrong Road, Imperial College London, London SW7 2AZ, U.K., Stanford University, Stanford, California, Hepadnavirus Testing, Inc., Mountain View, California, RNAi Co., Cosmos Hongo Bldg. 10F, 4-1-4, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan, and
| | - Masato Fujino
- Antiviral Gene Therapy Research Unit, Department of Molecular Medicine and Haematology, University of the Witwatersrand Medical School, Private Bag 3, WITS 2050, South Africa, Imperial College Genetic Therapies Centre, Department of Chemistry, Flowers Building, Armstrong Road, Imperial College London, London SW7 2AZ, U.K., Stanford University, Stanford, California, Hepadnavirus Testing, Inc., Mountain View, California, RNAi Co., Cosmos Hongo Bldg. 10F, 4-1-4, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan, and
| | - Yukikazu Natori
- Antiviral Gene Therapy Research Unit, Department of Molecular Medicine and Haematology, University of the Witwatersrand Medical School, Private Bag 3, WITS 2050, South Africa, Imperial College Genetic Therapies Centre, Department of Chemistry, Flowers Building, Armstrong Road, Imperial College London, London SW7 2AZ, U.K., Stanford University, Stanford, California, Hepadnavirus Testing, Inc., Mountain View, California, RNAi Co., Cosmos Hongo Bldg. 10F, 4-1-4, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan, and
| | - Maya Thanou
- Antiviral Gene Therapy Research Unit, Department of Molecular Medicine and Haematology, University of the Witwatersrand Medical School, Private Bag 3, WITS 2050, South Africa, Imperial College Genetic Therapies Centre, Department of Chemistry, Flowers Building, Armstrong Road, Imperial College London, London SW7 2AZ, U.K., Stanford University, Stanford, California, Hepadnavirus Testing, Inc., Mountain View, California, RNAi Co., Cosmos Hongo Bldg. 10F, 4-1-4, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan, and
| | - Patrick Arbuthnot
- Antiviral Gene Therapy Research Unit, Department of Molecular Medicine and Haematology, University of the Witwatersrand Medical School, Private Bag 3, WITS 2050, South Africa, Imperial College Genetic Therapies Centre, Department of Chemistry, Flowers Building, Armstrong Road, Imperial College London, London SW7 2AZ, U.K., Stanford University, Stanford, California, Hepadnavirus Testing, Inc., Mountain View, California, RNAi Co., Cosmos Hongo Bldg. 10F, 4-1-4, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan, and
| | - Andrew D. Miller
- Antiviral Gene Therapy Research Unit, Department of Molecular Medicine and Haematology, University of the Witwatersrand Medical School, Private Bag 3, WITS 2050, South Africa, Imperial College Genetic Therapies Centre, Department of Chemistry, Flowers Building, Armstrong Road, Imperial College London, London SW7 2AZ, U.K., Stanford University, Stanford, California, Hepadnavirus Testing, Inc., Mountain View, California, RNAi Co., Cosmos Hongo Bldg. 10F, 4-1-4, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan, and
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226
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Affiliation(s)
- Ji Hoon Jeong
- College of Pharmacy, Sungkyunkwan University, Suwon 440-746, South Korea, Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, South Korea, and School of Life Sciences and Biotechnology, Korea University, Anam-dong, Seungbuk-gu, Seoul, South Korea
| | - Hyejung Mok
- College of Pharmacy, Sungkyunkwan University, Suwon 440-746, South Korea, Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, South Korea, and School of Life Sciences and Biotechnology, Korea University, Anam-dong, Seungbuk-gu, Seoul, South Korea
| | - Yu-Kyoung Oh
- College of Pharmacy, Sungkyunkwan University, Suwon 440-746, South Korea, Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, South Korea, and School of Life Sciences and Biotechnology, Korea University, Anam-dong, Seungbuk-gu, Seoul, South Korea
| | - Tae Gwan Park
- College of Pharmacy, Sungkyunkwan University, Suwon 440-746, South Korea, Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, South Korea, and School of Life Sciences and Biotechnology, Korea University, Anam-dong, Seungbuk-gu, Seoul, South Korea
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227
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Lee H, Kim SI, Shin D, Yoon Y, Choi TH, Cheon GJ, Kim M. Hepatic siRNA delivery using recombinant human apolipoprotein A-I in mice. Biochem Biophys Res Commun 2008; 378:192-6. [PMID: 19017527 DOI: 10.1016/j.bbrc.2008.11.029] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2008] [Accepted: 11/04/2008] [Indexed: 10/21/2022]
Abstract
Apolipoprotein A-I (apo A-I), the major protein component of high density lipoprotein (HDL), plays a key role in reverse cholesterol transport from peripheral tissues to liver or steroidogenic organs. Class B, type 1 scavenger receptor (SR-BI) is abundantly expressed in these target tissues and recognizes apo A-I of HDL for selective cholesteryl ester uptake. Recently, we reported the liver-targeting potential of plasma-derived apo A-I and the efficient delivery of therapeutic small interfering RNAs (siRNA) assembled with cationic liposome and apo A-I. In this study, we expressed and purified recombinant human apo A-I (rhapo A-I), low endotoxin grade, from an Escherichia coli expression system. The liver-targeting property of rhapo A-I was compared to that of plasma-derived apo A-I. Using a hepatitis C virus mouse model, intravenous administration of virus-specific siRNA with liposome and rhapo A-I significantly inhibited viral protein expression, demonstrating great promise for its use in clinical applications.
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Affiliation(s)
- Hyeon Lee
- Virus Research Laboratory, Mogam Biotechnology Research Institute, 341 Bojeong-dong, Giheung-gu, Yongin-si, Gyeonggi-do 449-913, South Korea
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228
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Juliano R, Alam MR, Dixit V, Kang H. Mechanisms and strategies for effective delivery of antisense and siRNA oligonucleotides. Nucleic Acids Res 2008; 36:4158-71. [PMID: 18558618 PMCID: PMC2475625 DOI: 10.1093/nar/gkn342] [Citation(s) in RCA: 292] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The potential use of antisense and siRNA oligonucleotides as therapeutic agents has elicited a great deal of interest. However, a major issue for oligonucleotide-based therapeutics involves effective intracellular delivery of the active molecules. In this Survey and Summary, we review recent reports on delivery strategies, including conjugates of oligonucleotides with various ligands, as well as use of nanocarrier approaches. These are discussed in the context of intracellular trafficking pathways and issues regarding in vivo biodistribution of molecules and nanoparticles. Molecular-sized chemical conjugates and supramolecular nanocarriers each display advantages and disadvantages in terms of effective and nontoxic delivery. Thus, choice of an optimal delivery modality will likely depend on the therapeutic context.
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Affiliation(s)
- Rudy Juliano
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA.
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