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Tang Q, Khvorova A. RNAi-based drug design: considerations and future directions. Nat Rev Drug Discov 2024; 23:341-364. [PMID: 38570694 PMCID: PMC11144061 DOI: 10.1038/s41573-024-00912-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/14/2024] [Indexed: 04/05/2024]
Abstract
More than 25 years after its discovery, the post-transcriptional gene regulation mechanism termed RNAi is now transforming pharmaceutical development, proved by the recent FDA approval of multiple small interfering RNA (siRNA) drugs that target the liver. Synthetic siRNAs that trigger RNAi have the potential to specifically silence virtually any therapeutic target with unprecedented potency and durability. Bringing this innovative class of medicines to patients, however, has been riddled with substantial challenges, with delivery issues at the forefront. Several classes of siRNA drug are under clinical evaluation, but their utility in treating extrahepatic diseases remains limited, demanding continued innovation. In this Review, we discuss principal considerations and future directions in the design of therapeutic siRNAs, with a particular emphasis on chemistry, the application of informatics, delivery strategies and the importance of careful target selection, which together influence therapeutic success.
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Affiliation(s)
- Qi Tang
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Department of Dermatology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Anastasia Khvorova
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA, USA.
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA.
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He H, Chiu AC, Kanada M, Schaar BT, Krishnan V, Contag CH, Dorigo O. Imaging of Tumor-Associated Macrophages in a Transgenic Mouse Model of Orthotopic Ovarian Cancer. Mol Imaging Biol 2018; 19:694-702. [PMID: 28233218 DOI: 10.1007/s11307-017-1061-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE Tumor-associated macrophages (TAMs) are often associated with a poor prognosis in cancer. To gain a better understanding of cellular recruitment and dynamics of TAM biology during cancer progression, we established a novel transgenic mouse model for in vivo imaging of luciferase-expressing macrophages. PROCEDURES B6.129P2-Lyz2tm1(cre)Ifo/J mice, which express Cre recombinase under the control of the lysozyme M promoter (LysM) were crossed to Cre-lox Luc reporter mice (RLG), to produce LysM-LG mice whose macrophages express luciferase. Cell-type-specific luciferase expression in these mice was verified by flow cytometry, and via in vivo bioluminescence imaging under conditions where macrophages were either stimulated with lipopolysaccharide or depleted with clodronate liposomes. The distribution of activated macrophages was longitudinally imaged in two immunocompetent LysM-LG mouse models with either B16 melanoma or ID8 ovarian cancer cells. RESULTS In vivo imaging of LysM-LG mice showed luciferase activity was generated by macrophages. Clodronate liposome-mediated depletion of macrophages lowered overall bioluminescence while lipopolysaccharide injection increased macrophage bioluminescence in both the B16 and ID8 models. Tracking macrophages weekly in tumor-bearing animals after intraperitoneal (i.p.) or intraovarian (i.o.) injection resulted in distinct, dynamic patterns of macrophage activity. Animals with metastatic ovarian cancer after i.p. injection exhibited significantly higher peritoneal macrophage activity compared to animals after i.o. injection. CONCLUSION The LysM-LG model allows tracking of macrophage recruitment and activation during disease initiation and progression in a noninvasive manner. This model provides a tool to visualize and monitor the benefit of pharmacological interventions targeting macrophages in preclinical models.
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Affiliation(s)
- Huanhuan He
- Departments of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Alan C Chiu
- Departments of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Masamitsu Kanada
- Departments of Pediatrics, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Bruce T Schaar
- Departments of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Venkatesh Krishnan
- Departments of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Christopher H Contag
- Departments of Pediatrics, Stanford University School of Medicine, Stanford, CA, 94305, USA.,Departments of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA.,Departments of Radiology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Oliver Dorigo
- Departments of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
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Hyun S, Choi Y, Lee HN, Lee C, Oh D, Lee DK, Lee C, Lee Y, Yu J. Construction of histidine-containing hydrocarbon stapled cell penetrating peptides for in vitro and in vivo delivery of siRNAs. Chem Sci 2018; 9:3820-3827. [PMID: 29780514 PMCID: PMC5939838 DOI: 10.1039/c8sc00074c] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 03/12/2018] [Indexed: 12/14/2022] Open
Abstract
A hydrocarbon stapled peptide based strategy was used to develop an optimized cell penetrating peptide for siRNA delivery. Various stapled peptides, having amphipathic Leu- and Lys-rich regions, were prepared and their cell penetrating potentials were evaluated. One peptide, stEK, was found to have high cell penetration and siRNA delivery abilities at low nanomolar concentrations. In order to improve its ability to promote gene silencing, stEK was modified by replacing several Lys residues with His moieties. The modified peptide, LKH-stEK, was found to facilitate endosomal escape and to display >90% knock-down with 50 nM of a siRNA targeting cyclophilin B in HeLa cells. The results of an in vivo animal wound healing model study demonstrate that LKH-stEK promotes delivery of an siRNA, which targets the connective tissue growth factor, and that this process leads to efficient gene silencing by the siRNA at a nanomolar level in mouse skin.
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Affiliation(s)
- Soonsil Hyun
- Institute of Molecular Biology and Genetics , Seoul National University , Seoul 08826 , Korea
| | - Yoonhwa Choi
- Department of Chemistry & Education , Seoul National University , Seoul 08826 , Korea .
| | | | | | | | - Dong-Ki Lee
- Department of Chemistry , Sungkyunkwan University , Suwon , Korea
| | | | - Yan Lee
- Department of Chemistry , Seoul National University , Seoul 08826 , Korea .
| | - Jaehoon Yu
- Institute of Molecular Biology and Genetics , Seoul National University , Seoul 08826 , Korea
- Department of Chemistry & Education , Seoul National University , Seoul 08826 , Korea .
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Liu PK, Liu CH. Epigenetics of amphetamine-induced sensitization: HDAC5 expression and microRNA in neural remodeling. J Biomed Sci 2016; 23:90. [PMID: 27931227 PMCID: PMC5146867 DOI: 10.1186/s12929-016-0294-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 10/26/2016] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Histone deacetylase (HDAC) activities modify chromatin structure and play a role in learning and memory during developmental processes. Studies of adult mice suggest HDACs are involved in neural network remodeling in brain repair, but its function in drug addiction is less understood. We aimed to examine in vivo HDAC5 expression in a preclinical model of amphetamine-induced sensitization (AIS) of behavior. We generated specific contrast agents to measure HDAC5 levels by in vivo molecular contrast-enhanced (MCE) magnetic resonance imaging (MRI) in amphetamine-naïve mice as well as in mice with AIS. To validate the MRI results we used ex vivo methods including in situ hybridization, RT-PCR, immunohistochemistry, and transmision electron microscopy. METHODS We compared the expression of HDAC5 mRNA in an acute exposure paradigm (in which animals experienced a single drug exposure [A1]) and in a chronic-abstinence-challenge paradigm (in which animals were exposed to the drug once every other day for seven doses, then underwent 2 weeks of abstinence followed by a challenge dose [A7WA]). Control groups for each of these exposure paradigms were given saline. To delineate how HDAC5 expression was related to AIS, we compared the expression of HDAC5 mRNA at sequences where no known microRNA (miR) binds (hdac5AS2) and at sequences where miR-2861 is known to bind (miD2861). We synthesized and labeled phosphorothioated oligonucleic acids (sODN) of hdac5AS2 or miD2861 linked to superparamagentic iron oxide nanoparticles (SPION), and generated HDAC5-specific contrast agents (30 ± 20 nm, diameter) for MCE MRI; the same sequences were used for primers for TaqMan® analysis (RT-qPCR) in ex vivo validation. In addition, we used subtraction R2* maps to identify regional HDAC5 expression. RESULTS Naïve C57black6 mice that experience acute exposure to amphetamine (4 mg/kg, by injection intraperitoneally) show expression of both total and phosphorylated (S259) HDAC5 antigens in GFAP+ and GFAP- cells, but the appearance of these cells was attenuated in the chronic paradigm. We found that MCE MRI reports HDAC5 mRNA with precision in physiological conditions because the HDAC5 mRNA copy number reported by TaqMan analysis was positively correlated (with a linear coefficient of 1.0) to the ΔR2* values (the frequency of signal reduction above background, 1/s) measured by MRI. We observed SPION-mid2861 as electron dense nanoparticles (EDNs) of less than 30 nm in the nucleus of the neurons, macrophages, and microglia, but not in glia and endothelia. We found no preferential distribution in any particular type of neural cells, but observed scattered EDNs of 60-150 nm (dia) in lysosomes. In the acute paradigm, mice pretreated with miD2861 (1.2 mmol/kg, i.p./icv) exhibited AIS similar to that exibited by mice in the chronic exposure group, which exhibited null response to mid2861 pretreatment. Moreover, SPION-miD2861 identified enhanced HDAC5 expression in the lateral septum and the striatum after amphetamine, where we found neurprogenitor cells coexpressing NeuN and GFAP. CONCLUSIONS We conclude that miD2681 targets HDAC5 mRNA with precision similar to that of RT-PCR. Our MCE MRI detects RNA-bound nanoparticles (NPs) in vivo, and ex vivo validation methods confirm that EDNs do not accumulate in any particular cell type. As HDAC5 expression may help nullify AIS and identify progenitor cells, the precise delivery of miD2861 may serve as a vehicle for monitoring network remodeling with target specificity and signal sensitivity after drug exposure that identifies brain repair processes in adult animals.
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Affiliation(s)
- Philip K Liu
- Department of Radiology, Molecular Contrast-Enhanced MRI Laboratory at the Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and the Harvard Medical School, CNY149 (2301) Thirteenth Street, Charlestown, MA, 02129, USA.
| | - Christina H Liu
- Department of Radiology, Molecular Contrast-Enhanced MRI Laboratory at the Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and the Harvard Medical School, CNY149 (2301) Thirteenth Street, Charlestown, MA, 02129, USA
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Hickerson RP, Speaker TJ, Lara MF, González-González E, Flores MA, Contag CH, Kaspar RL. Non-Invasive Intravital Imaging of siRNA-Mediated Mutant Keratin Gene Repression in Skin. Mol Imaging Biol 2016; 18:34-42. [PMID: 26169581 DOI: 10.1007/s11307-015-0875-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE Small interfering RNAs (siRNAs) specifically and potently inhibit target gene expression. Pachyonychia congenita (PC) is a skin disorder caused by mutations in genes encoding keratin (K) 6a/b, K16, and K17, resulting in faulty intermediate filaments. A siRNA targeting a single nucleotide, PC-relevant mutation inhibits K6a expression and has been evaluated in the clinic with encouraging results. PROCEDURES To better understand the pathophysiology of PC, and develop a model system to study siRNA delivery and visualize efficacy in skin, wild type (WT) and mutant K6a complementary DNAs (cDNAs) were fused to either enhanced green fluorescent protein or tandem tomato fluorescent protein cDNA to allow covisualization of mutant and WT K6a expression in mouse footpad skin using a dual fluorescence in vivo confocal imaging system equipped with 488 and 532 nm lasers. RESULTS Expression of mutant K6a/reporter resulted in visualization of keratin aggregates, while expression of WT K6a/reporter led to incorporation into filaments. Addition of mutant K6a-specific siRNA resulted in inhibition of mutant, but not WT, K6a/reporter expression. CONCLUSIONS Intravital imaging offers subcellular resolution for tracking functional activity of siRNA in real time and enables detailed analyses of therapeutic effects in individual mice to facilitate development of nucleic acid-based therapeutics for skin disorders.
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Affiliation(s)
- Robyn P Hickerson
- TransDerm Inc., 2161 Delaware Ave., Santa Cruz, CA, 95060, USA.,Centre for Dermatology and Genetic Medicine, University of Dundee, Dundee, UK
| | - Tycho J Speaker
- TransDerm Inc., 2161 Delaware Ave., Santa Cruz, CA, 95060, USA
| | - Maria Fernanda Lara
- TransDerm Inc., 2161 Delaware Ave., Santa Cruz, CA, 95060, USA.,Urology Research Unit Virgen de la Victoria and Regional Hospital, Malaga, Spain
| | - Emilio González-González
- Molecular Imaging Program at Stanford (MIPS), Stanford University School of Medicine, Stanford, CA, USA.,Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA.,Canvax Biotech S.L., Technological Park, Cordoba, Spain
| | - Manuel A Flores
- TransDerm Inc., 2161 Delaware Ave., Santa Cruz, CA, 95060, USA
| | - Christopher H Contag
- Molecular Imaging Program at Stanford (MIPS), Stanford University School of Medicine, Stanford, CA, USA.,Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA.,Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA.,Departments of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA
| | - Roger L Kaspar
- TransDerm Inc., 2161 Delaware Ave., Santa Cruz, CA, 95060, USA.
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Chen W, Li H, Shi D, Liu Z, Yuan W. Microneedles As a Delivery System for Gene Therapy. Front Pharmacol 2016; 7:137. [PMID: 27303298 PMCID: PMC4880556 DOI: 10.3389/fphar.2016.00137] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 05/10/2016] [Indexed: 01/20/2023] Open
Abstract
Gene delivery systems can be divided to two major types: vector-based (either viral vector or non-viral vector) and physical delivery technologies. Many physical carriers, such as electroporation, gene gun, ultrasound start to be proved to have the potential to enable gene therapy. A relatively new physical delivery technology for gene delivery consists of microneedles (MNs), which has been studied in many fields and for many molecule types and indications. Microneedles can penetrate the stratum corneum, which is the main barrier for drug delivery through the skin with ease of administration and without significant pain. Many different kinds of MNs, such as metal MNs, coated MNs, dissolving MNs have turned out to be promising in gene delivery. In this review, we discussed the potential as well as the challenges of utilizing MNs to deliver nucleic acids for gene therapy. We also proposed that a combination of MNs and other gene delivery approaches may lead to a better delivery system for gene therapy.
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Affiliation(s)
- Wei Chen
- Department of Neurology, Xinhua Hospital affiliated to the Medical School of Shanghai Jiao Tong University Shanghai, China
| | - Hui Li
- School of Pharmacy, Shanghai Jiao Tong University Shanghai, China
| | - De Shi
- Department of Neurology, Xinhua Hospital affiliated to the Medical School of Shanghai Jiao Tong University Shanghai, China
| | - Zhenguo Liu
- Department of Neurology, Xinhua Hospital affiliated to the Medical School of Shanghai Jiao Tong University Shanghai, China
| | - Weien Yuan
- School of Pharmacy, Shanghai Jiao Tong University Shanghai, China
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7
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Zou Y, Guo CG, Yang ZG, Sun JH, Zhang MM, Fu CY. A small interfering RNA targeting vascular endothelial growth factor efficiently inhibits growth of VX2 cells and VX2 tumor model of hepatocellular carcinoma in rabbit by transarterial embolization-mediated siRNA delivery. DRUG DESIGN DEVELOPMENT AND THERAPY 2016; 10:1243-55. [PMID: 27069355 PMCID: PMC4818046 DOI: 10.2147/dddt.s94122] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Introduction Hepatocellular carcinoma is currently the second leading cause of cancer-related deaths worldwide with an increasing incidence. Objective The objective of this study is to investigate the effect of vascular endothelial growth factor small interfering RNA (VEGF-siRNA) on rabbit VX2 carcinoma cell viability in vitro and the effect of transarterial embolization (TAE)-mediated VEGF-siRNA delivery on the growth of rabbit VX2 liver-transplanted model in vivo. Methods Quantitative reverse transcription polymerase chain reaction, enzyme-linked immunosorbent assay, and Western blot technologies were used to detect the expression level of VEGF. TAE and computed tomography scan were used to deliver the VEGF-siRNA and detect the tumor volume in vivo, respectively. Microvessel density was detected by immunohistochemistry with CD34 antibody. A biochemical autoanalyzer was used to evaluate the hepatic and renal toxicity. Results The designed VEGF-siRNAs could effectively decrease the expression levels of VEGF mRNA and protein in vitro and in vivo. In vitro, the viability of rabbit VX2 carcinoma cells was reduced by 38.5%±7.3% (VEGF-siRNA no 1) and 30.0%±5.8% (VEGF-siRNA no 3) at 48 hours after transfection. Moreover, in rabbit VX2 liver-transplanted model, the growth ratios of tumors at 28 days after TAE-mediated siRNA delivery were 155.18%±19.42% in the control group, 79.67%±19.63% in the low-dose group, and 36.09%±15.73% in the high-dose group, with significant differences among these three groups. Microvessel density dropped to 34.22±4.01 and 22.63±4.07 in the low-dose group and high-dose group, respectively, compared with the control group (57.88±5.67), with significant differences among these three groups. Furthermore, inoculation of VX2 tumor into the liver itself at later stage induced significant increase in alanine aminotransferase and aspartate aminotransferase, indicating an obvious damage of liver functions, while treatment of VX2 tumor via TAE-mediated VEGF-siRNA had no toxicity to the livers and kidneys of rabbits, and VEGF-siRNA had the ability to protect liver damage induced by tumor growth. Conclusion This is the first study to demonstrate that targeting VEGF via TAE-mediated siRNA delivery may become a powerful new option for effective treatment of hepatocellular carcinoma in the clinic.
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Affiliation(s)
- Yu Zou
- Department of Radiology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, People's Republic of China; Department of Radiology, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, People's Republic of China
| | - Chuan-Gen Guo
- Department of Radiology, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, People's Republic of China
| | - Zheng-Gang Yang
- Institute of Infectious Diseases, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, People's Republic of China
| | - Jun-Hui Sun
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, People's Republic of China
| | - Min-Ming Zhang
- Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, People's Republic of China
| | - Cai-Yun Fu
- College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, People's Republic of China; Key Laboratory of Cell-Based Drug and Applied Technology Development in Zhejiang Province, Hangzhou, People's Republic of China
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Rejinold NS, Shin JH, Seok HY, Kim YC. Biomedical applications of microneedles in therapeutics: recent advancements and implications in drug delivery. Expert Opin Drug Deliv 2015; 13:109-31. [DOI: 10.1517/17425247.2016.1115835] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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9
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Kaspar RL, Hickerson RP, González-González E, Flores MA, Speaker TP, Rogers FA, Milstone LM, Contag CH. Imaging Functional Nucleic Acid Delivery to Skin. Methods Mol Biol 2015; 1372:1-24. [PMID: 26530911 DOI: 10.1007/978-1-4939-3148-4_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Monogenic skin diseases arise from well-defined single gene mutations, and in some cases a single point mutation. As the target cells are superficial, these diseases are ideally suited for treatment by nucleic acid-based therapies as well as monitoring through a variety of noninvasive imaging technologies. Despite the accessibility of the skin, there remain formidable barriers for functional delivery of nucleic acids to the target cells within the dermis and epidermis. These barriers include the stratum corneum and the layered structure of the skin, as well as more locally, the cellular, endosomal and nuclear membranes. A wide range of technologies for traversing these barriers has been described and moderate success has been reported for several approaches. The lessons learned from these studies include the need for combinations of approaches to facilitate nucleic acid delivery across these skin barriers and then functional delivery across the cellular and nuclear membranes for expression (e.g., reporter genes, DNA oligonucleotides or shRNA) or into the cytoplasm for regulation (e.g., siRNA, miRNA, antisense oligos). The tools for topical delivery that have been evaluated include chemical, physical and electrical methods, and the development and testing of each of these approaches has been greatly enabled by imaging tools. These techniques allow delivery and real time monitoring of reporter genes, therapeutic nucleic acids and also triplex nucleic acids for gene editing. Optical imaging is comprised of a number of modalities based on properties of light-tissue interaction (e.g., scattering, autofluorescence, and reflectance), the interaction of light with specific molecules (e.g., absorbtion, fluorescence), or enzymatic reactions that produce light (bioluminescence). Optical imaging technologies operate over a range of scales from macroscopic to microscopic and if necessary, nanoscopic, and thus can be used to assess nucleic acid delivery to organs, regions, cells and even subcellular structures. Here we describe the animal models, reporter genes, imaging approaches and general strategies for delivery of nucleic acids to cells in the skin for local expression (e.g., plasmid DNA) or gene silencing (e.g., siRNA) with the intent of developing nucleic acid-based therapies to treat diseases of the skin.
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Affiliation(s)
- Roger L Kaspar
- TransDerm Inc., 2161 Delaware Ave, Santa Cruz, CA, 95060, USA.
| | - Robyn P Hickerson
- Centre for Dermatology and Genetic Medicine, University of Dundee, Dundee, UK
| | | | - Manuel A Flores
- TransDerm Inc., 2161 Delaware Ave, Santa Cruz, CA, 95060, USA
| | - Tycho P Speaker
- TransDerm Inc., 2161 Delaware Ave, Santa Cruz, CA, 95060, USA
| | - Faye A Rogers
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, USA
| | - Leonard M Milstone
- Department of Dermatology, Yale University School of Medicine, New Haven, CT, USA
| | - Christopher H Contag
- Molecular Imaging Program at Stanford (MIPS), E150 Clark Center, Stanford University School of Medicine, 318 Campus Drive, Stanford, CA, 94305, USA. .,Department of Pediatrics, E150 Clark Center, Stanford University School of Medicine, 318 Campus Drive, Stanford, CA, 94305, USA. .,Department of Radiology, E150 Clark Center, Stanford University School of Medicine, 318 Campus Drive, Stanford, CA, 94305, USA. .,Microbiology and Immunology, E150 Clark Center, Stanford University School of Medicine, 318 Campus Drive, Stanford, CA, 94305, USA.
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Differential fates of biomolecules delivered to target cells via extracellular vesicles. Proc Natl Acad Sci U S A 2015; 112:E1433-42. [PMID: 25713383 DOI: 10.1073/pnas.1418401112] [Citation(s) in RCA: 342] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Extracellular vesicles (EVs), specifically exosomes and microvesicles (MVs), are presumed to play key roles in cell-cell communication via transfer of biomolecules between cells. The biogenesis of these two types of EVs differs as they originate from either the endosomal (exosomes) or plasma (MVs) membranes. To elucidate the primary means through which EVs mediate intercellular communication, we characterized their ability to encapsulate and deliver different types of macromolecules from transiently transfected cells. Both EV types encapsulated reporter proteins and mRNA but only MVs transferred the reporter function to recipient cells. De novo reporter protein expression in recipient cells resulted only from plasmid DNA (pDNA) after delivery via MVs. Reporter mRNA was delivered to recipient cells by both EV types, but was rapidly degraded without being translated. MVs also mediated delivery of functional pDNA encoding Cre recombinase in vivo to tissues in transgenic Cre-lox reporter mice. Within the parameters of this study, MVs delivered functional pDNA, but not RNA, whereas exosomes from the same source did not deliver functional nucleic acids. These results have significant implications for understanding the role of EVs in cellular communication and for development of EVs as delivery tools. Moreover, studies using EVs from transiently transfected cells may be confounded by a predominance of pDNA transfer.
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Wender PA, Huttner MA, Staveness D, Vargas JR, Xu AF. Guanidinium-Rich, Glycerol-Derived Oligocarbonates: A New Class of Cell-Penetrating Molecular Transporters That Complex, Deliver, and Release siRNA. Mol Pharm 2015; 12:742-50. [DOI: 10.1021/mp500581r] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Paul A. Wender
- Departments of Chemistry and Chemical and Systems Biology, Stanford University, Stanford, California 94305, United States
| | - Melanie A. Huttner
- Departments of Chemistry and Chemical and Systems Biology, Stanford University, Stanford, California 94305, United States
| | - Daryl Staveness
- Departments of Chemistry and Chemical and Systems Biology, Stanford University, Stanford, California 94305, United States
| | - Jessica R. Vargas
- Departments of Chemistry and Chemical and Systems Biology, Stanford University, Stanford, California 94305, United States
| | - Adele F. Xu
- Departments of Chemistry and Chemical and Systems Biology, Stanford University, Stanford, California 94305, United States
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Hegde V, Hickerson RP, Nainamalai S, Campbell PA, Smith FJD, McLean WHI, Pedrioli DML. In vivo gene silencing following non-invasive siRNA delivery into the skin using a novel topical formulation. J Control Release 2014; 196:355-62. [PMID: 25449884 PMCID: PMC4275573 DOI: 10.1016/j.jconrel.2014.10.022] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 10/20/2014] [Accepted: 10/23/2014] [Indexed: 12/17/2022]
Abstract
Therapeutics based on short interfering RNAs (siRNAs), which act by inhibiting the expression of target transcripts, represent a novel class of potent and highly specific next-generation treatments for human skin diseases. Unfortunately, the intrinsic barrier properties of the skin combined with the large size and negative charge of siRNAs make epidermal delivery of these macromolecules quite challenging. To help evaluate the in vivo activity of these therapeutics and refine delivery strategies we generated an innovative reporter mouse model that predominantly expresses firefly luciferase (luc2p) in the paw epidermis--the region of murine epidermis that most closely models the tissue architecture of human skin. Combining this animal model with state-of-the-art live animal imaging techniques, we have developed a real-time in vivo analysis work-flow that has allowed us to compare and contrast the efficacies of a wide range nucleic acid-based gene silencing reagents in the skin of live animals. While inhibition was achieved with all of the reagents tested, only the commercially available "self-delivery" modified Accell-siRNAs (Dharmacon) produced potent and sustained in vivo gene silencing. Together, these findings highlight just how informative reliable reporter mouse models can be when assessing novel therapeutics in vivo. Using this work-flow, we developed a novel clinically-relevant topical formulation that facilitates non-invasive epidermal delivery of unmodified and "self-delivery" siRNAs. Remarkably, a sustained >40% luc2p inhibition was observed after two 1-hour treatments with Accell-siRNAs in our topical formulation. Importantly, our ability to successfully deliver siRNA molecules topically brings these novel RNAi-based therapeutics one-step closer to clinical use.
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Affiliation(s)
- Vikas Hegde
- Centre for Dermatology and Genetic Medicine, Division of Molecular Medicine, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Robyn P Hickerson
- Centre for Dermatology and Genetic Medicine, Division of Molecular Medicine, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Sitheswaran Nainamalai
- Centre for Dermatology and Genetic Medicine, Division of Molecular Medicine, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Paul A Campbell
- Centre for Dermatology and Genetic Medicine, Division of Molecular Medicine, University of Dundee, Dundee DD1 5EH, Scotland, UK; Carnegie Physics Laboratory, University of Dundee, Dundee DD1 4HN, Scotland, UK
| | - Frances J D Smith
- Centre for Dermatology and Genetic Medicine, Division of Molecular Medicine, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - W H Irwin McLean
- Centre for Dermatology and Genetic Medicine, Division of Molecular Medicine, University of Dundee, Dundee DD1 5EH, Scotland, UK.
| | - Deena M Leslie Pedrioli
- Centre for Dermatology and Genetic Medicine, Division of Molecular Medicine, University of Dundee, Dundee DD1 5EH, Scotland, UK.
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Nayak TR, Krasteva LK, Cai W. Multimodality imaging of RNA interference. Curr Med Chem 2014; 20:3664-75. [PMID: 23745567 DOI: 10.2174/0929867311320290012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 03/13/2013] [Accepted: 03/13/2013] [Indexed: 12/16/2022]
Abstract
The discovery of small interfering RNAs (siRNAs) and their potential to knock down virtually any gene of interest has ushered in a new era of RNA interference (RNAi). Clinical use of RNAi faces severe limitations due to inefficiency delivery of siRNA or short hairpin RNA (shRNA). Many molecular imaging techniques have been adopted in RNAi-related research for evaluation of siRNA/shRNA delivery, biodistribution, pharmacokinetics, and the therapeutic effect. In this review article, we summarize the current status of in vivo imaging of RNAi. The molecular imaging techniques that have been employed include bioluminescence/fluorescence imaging, magnetic resonance imaging/ spectroscopy, positron emission tomography, single-photon emission computed tomography, and various combinations of these techniques. Further development of non-invasive imaging strategies for RNAi, not only focusing on the delivery of siRNA/shRNA but also the therapeutic efficacy, is critical for future clinical translation. Rigorous validation will be needed to confirm that biodistribution of the carrier is correlated with that of siRNA/shRNA, since imaging only detects the label (e.g. radioisotopes) but not the gene or carrier themselves. It is also essential to develop multimodality imaging approaches for realizing the full potential of therapeutic RNAi, as no single imaging modality may be sufficient to simultaneously monitor both the gene delivery and silencing effect of RNAi.
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Affiliation(s)
- T R Nayak
- Department of Radiology, University of Wisconsin - Madison, Madison, WI 53705-2275, USA
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14
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Hickerson RP, Wey WC, Rimm DL, Speaker T, Suh S, Flores MA, Gonzalez-Gonzalez E, Leake D, Contag CH, Kaspar RL. Gene Silencing in Skin After Deposition of Self-Delivery siRNA With a Motorized Microneedle Array Device. MOLECULAR THERAPY. NUCLEIC ACIDS 2013; 2:e129. [PMID: 24150576 PMCID: PMC4027428 DOI: 10.1038/mtna.2013.56] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 08/08/2013] [Indexed: 01/08/2023]
Abstract
Despite the development of potent siRNAs that effectively target genes responsible for skin disorders, translation to the clinic has been hampered by inefficient delivery through the stratum corneum barrier and into the live cells of the epidermis. Although hypodermic needles can be used to transport siRNA through the stratum corneum, this approach is limited by pain caused by the injection and the small volume of tissue that can be accessed by each injection. The use of microneedle arrays is a less painful method for siRNA delivery, but restricted payload capacity limits this approach to highly potent molecules. To address these challenges, a commercially available motorized microneedle array skin delivery device was evaluated. This device combines the positive elements of both hypodermic needles and microneedle array technologies with little or no pain to the patient. Application of fluorescently tagged self-delivery (sd)-siRNA to both human and murine skin resulted in distribution throughout the treated skin. In addition, efficient silencing (78% average reduction) of reporter gene expression was achieved in a transgenic fluorescent reporter mouse skin model. These results indicate that this device effectively delivers functional sd-siRNA with an efficiency that predicts successful clinical translation.
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Affiliation(s)
- Robyn P Hickerson
- 1] TransDerm, Santa Cruz, California, USA [2] Current address: University of Dundee, Dundee, UK
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Noninvasive delivery of siRNA and plasmid DNA into skin by fractional ablation: erbium:YAG laser versus CO₂ laser. Eur J Pharm Biopharm 2013; 86:315-23. [PMID: 23962771 DOI: 10.1016/j.ejpb.2013.08.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 07/31/2013] [Accepted: 08/05/2013] [Indexed: 12/21/2022]
Abstract
The present study was conducted to evaluate the impacts of fractional erbium (Er):YAG and CO2 lasers on skin permeation of small interfering (si)RNA and plasmid (p)DNA vectors. In vitro skin delivery was determined with a Franz diffusion cell. In vivo absorption was investigated by observing fluorescence and confocal microscopic imaging. Fractional laser-mediated ablation of the skin resulted in significant enhancement of dextran and siRNA penetration. Respective fluxes of dextran (10 kDa) and siRNA, which had similar molecular size, with Er:YAG laser irradiation at 5 J/cm(2) were 56- and 11-fold superior to that of intact skin. The respective permeation extents of dextran and siRNA by the CO2 laser at 4 mJ/400 spots were 42- and 12-fold greater than that of untreated skin. Fluorescence and confocal images showed increased fluorescence intensities and penetration depths of siRNA and pDNA delivery. According to an examination of the follicular permeant amount and fluorescence microscopy, hair follicles were important deposition areas for fractional laser-assisted delivery, with the Er:YAG modality revealing higher follicular siRNA selectivity than the CO2 modality. This is the first report of siRNA and pDNA penetrating the skin with a sufficient amount and depth with the assistance of fractional lasers.
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Chong RHE, Gonzalez-Gonzalez E, Lara MF, Speaker TJ, Contag CH, Kaspar RL, Coulman SA, Hargest R, Birchall JC. Gene silencing following siRNA delivery to skin via coated steel microneedles: In vitro and in vivo proof-of-concept. J Control Release 2013; 166:211-9. [PMID: 23313112 DOI: 10.1016/j.jconrel.2012.12.030] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 12/24/2012] [Accepted: 12/30/2012] [Indexed: 11/28/2022]
Abstract
The development of siRNA-based gene silencing therapies has significant potential for effectively treating debilitating genetic, hyper-proliferative or malignant skin conditions caused by aberrant gene expression. To be efficacious and widely accepted by physicians and patients, therapeutic siRNAs must access the viable skin layers in a stable and functional form, preferably without painful administration. In this study we explore the use of minimally-invasive steel microneedle devices to effectively deliver siRNA into skin. A simple, yet precise microneedle coating method permitted reproducible loading of siRNA onto individual microneedles. Following recovery from the microneedle surface, lamin A/C siRNA retained full activity, as demonstrated by significant reduction in lamin A/C mRNA levels and reduced lamin A/C protein in HaCaT keratinocyte cells. However, lamin A/C siRNA pre-complexed with a commercial lipid-based transfection reagent (siRNA lipoplex) was less functional following microneedle coating. As Accell-modified "self-delivery" siRNA targeted against CD44 also retained functionality after microneedle coating, this form of siRNA was used in subsequent in vivo studies, where gene silencing was determined in a transgenic reporter mouse skin model. Self-delivery siRNA targeting the reporter (luciferase/GFP) gene was coated onto microneedles and delivered to mouse footpad. Quantification of reporter mRNA and intravital imaging of reporter expression in the outer skin layers confirmed functional in vivo gene silencing following microneedle delivery of siRNA. The use of coated metal microneedles represents a new, simple, minimally-invasive, patient-friendly and potentially self-administrable method for the delivery of therapeutic nucleic acids to the skin.
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Affiliation(s)
- Rosalind H E Chong
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, UK
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17
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Liquid crystalline phase nanodispersions enable skin delivery of siRNA. Eur J Pharm Biopharm 2013; 83:16-24. [DOI: 10.1016/j.ejpb.2012.08.011] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Revised: 05/04/2012] [Accepted: 08/22/2012] [Indexed: 01/03/2023]
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18
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Hickerson RP, Gonzalez-Gonzalez E, Vlassov AV, Li M, Lara MF, Contag CH, Kaspar RL. Intravital fluorescence imaging of small interfering RNA-mediated gene repression in a dual reporter melanoma xenograft model. Nucleic Acid Ther 2012; 22:438-43. [PMID: 23098239 DOI: 10.1089/nat.2012.0364] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Development of RNA interference (RNAi)-based therapeutics has been hampered by the lack of effective and efficient means of delivery. Reliable model systems for screening and optimizing delivery of RNAi-based agents in vivo are crucial for preclinical research aimed at advancing nucleic acid-based therapies. We describe here a dual fluorescent reporter xenograft melanoma model prepared by intradermal injection of human A375 melanoma cells expressing tandem tomato fluorescent protein (tdTFP) containing a small interfering RNA (siRNA) target site as well as enhanced green fluorescent protein (EGFP), which is used as a normalization control. Intratumoral injection of a siRNA specific to the incorporated siRNA target site, complexed with a cationic lipid that has been optimized for in vivo delivery, resulted in 65%±11% knockdown of tdTFP relative to EGFP quantified by in vivo imaging and 68%±10% by reverse transcription-quantitative polymerase chain reaction. No effect was observed with nonspecific control siRNA treatment. This model provides a platform on which siRNA delivery technologies can be screened and optimized in vivo.
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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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Chamcheu JC, Wood GS, Siddiqui IA, Syed DN, Adhami VM, Teng JM, Mukhtar H. Progress towards genetic and pharmacological therapies for keratin genodermatoses: current perspective and future promise. Exp Dermatol 2012; 21:481-9. [PMID: 22716242 PMCID: PMC3556927 DOI: 10.1111/j.1600-0625.2012.01534.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Hereditary keratin disorders of the skin and its appendages comprise a large group of clinically heterogeneous disfiguring blistering and ichthyotic diseases, primarily characterized by the loss of tissue integrity, blistering and hyperkeratosis in severely affected tissues. Pathogenic mutations in keratins cause these afflictions. Typically, these mutations in concert with characteristic features have formed the basis for improved disease diagnosis, prognosis and most recently therapy development. Examples include epidermolysis bullosa simplex, keratinopathic ichthyosis, pachyonychia congenita and several other tissue-specific hereditary keratinopathies. Understanding the molecular and genetic events underlying skin dysfunction has initiated alternative treatment approaches that may provide novel therapeutic opportunities for affected patients. Animal and in vitro disease modelling studies have shed more light on molecular pathogenesis, further defining the role of keratins in disease processes and promoting the translational development of new gene and pharmacological therapeutic strategies. Given that the molecular basis for these monogenic disorders is well established, gene therapy and drug discovery targeting pharmacological compounds with the ability to reinforce the compromised cytoskeleton may lead to promising new therapeutic strategies for treating hereditary keratinopathies. In this review, we will summarize and discuss recent advances in the preclinical and clinical modelling and development of gene, natural product, pharmacological and protein-based therapies for these disorders, highlighting the feasibility of new approaches for translational clinical therapy.
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Affiliation(s)
- Jean Christopher Chamcheu
- Department of Dermatology, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
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21
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Abstract
Post-transcriptional managing of RNA plays a key role in the intricate network of cellular pathways that regulate our genes. Numerous small RNA species have emerged as crucial regulators of RNA processing and translation. Among these, microRNAs (miRNAs) regulate protein synthesis through specific interactions with target RNAs and are believed to play a role in almost any cellular process and tissue. Skin is no exception, and miRNAs are intensively studied for their role in skin homoeostasis and as potential triggers of disease. For use in skin and many other tissues, therapeutic RNA managing by small RNA technologies is now widely explored. Despite the easy accessibility of skin, the natural barrier properties of skin have challenged genetic intervention studies, and unique tools for studying gene expression and the regulatory role of small RNAs, including miRNAs, in human skin are urgently needed. Human immunodeficiency virus (HIV)-derived lentiviral vectors (LVs) have been established as prominent carriers of foreign genetic cargo. In this review, we describe the use of HIV-derived LVs for efficient gene transfer to skin and establishment of long-term transgene expression in xenotransplanted skin. We outline the status of engineered LVs for delivery of small RNAs and their in vivo applicability for expression of genes and small RNA effectors including small hairpin RNAs, miRNAs and miRNA inhibitors. Current findings suggest that LVs may become key tools in experimental dermatology with particular significance for cutaneous RNA managing and in vivo genetic intervention.
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Lara MF, González-González E, Speaker TJ, Hickerson RP, Leake D, Milstone LM, Contag CH, Kaspar RL. Inhibition of CD44 gene expression in human skin models, using self-delivery short interfering RNA administered by dissolvable microneedle arrays. Hum Gene Ther 2012; 23:816-23. [PMID: 22480249 DOI: 10.1089/hum.2011.211] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Treatment of skin disorders with short interfering RNA (siRNA)-based therapeutics requires the development of effective delivery methodologies that reach target cells in affected tissues. Successful delivery of functional siRNA to the epidermis requires (1) crossing the stratum corneum, (2) transfer across the keratinocyte membrane, followed by (3) incorporation into the RNA-induced silencing complex. We have previously demonstrated that treatment with microneedle arrays loaded with self-delivery siRNA (sd-siRNA) can achieve inhibition of reporter gene expression in a transgenic mouse model. Furthermore, treatment of human cultured epidermal equivalents with sd-siRNA resulted in inhibition of target gene expression. Here, we demonstrate inhibition of CD44, a gene that is uniformly expressed throughout the epidermis, by sd-siRNA both in vitro (cultured human epidermal skin equivalents) and in vivo (full-thickness human skin equivalents xenografted on immunocompromised mice). Treatment of human skin equivalents with CD44 sd-siRNA markedly decreased CD44 mRNA levels, which led to a reduction of the target protein as confirmed by immunodetection in epidermal equivalent sections with a CD44-specific antibody. Taken together, these results demonstrate that sd-siRNA, delivered by microneedle arrays, can reduce expression of a targeted endogenous gene in a human skin xenograft model.
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23
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Lobovkina T, Jacobson GB, Gonzalez EG, Hickerson RP, Leake D, Kaspar RL, Contag CH, Zare RN. In vivo sustained release of siRNA from solid lipid nanoparticles. ACS NANO 2011; 5:9977-83. [PMID: 22077198 PMCID: PMC3246574 DOI: 10.1021/nn203745n] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Small interfering RNA (siRNA) is a highly potent drug in gene-based therapy with a challenge of being delivered in a sustained manner. Nanoparticle drug delivery systems allow for incorporating and controlled release of therapeutic payloads. We demonstrate that solid lipid nanoparticles can incorporate and provide sustained release of siRNA. Tristearin solid lipid nanoparticles, made by nanoprecipitation, were loaded with siRNA (4.4-5.5 wt % loading ratio) using a hydrophobic ion pairing approach that employs the cationic lipid DOTAP. Intradermal injection of these nanocarriers in mouse footpads resulted in prolonged siRNA release over a period of 10-13 days. In vitro cell studies showed that the released siRNA retained its activity. Nanoparticles developed in this study offer an alternative approach to polymeric nanoparticles for encapsulation and sustained delivery of siRNA with the advantage of being prepared from physiologically well-tolerated materials.
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Affiliation(s)
- Tatsiana Lobovkina
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, CA, 94305-5080 USA
| | - Gunilla B. Jacobson
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, CA, 94305-5080 USA
| | - Emilio Gonzalez Gonzalez
- Department of Pediatrics, Stanford School of Medicine, Stanford, CA 94305-5427 USA
- Molecular Imaging Program, Stanford University, Stanford, CA 94305-5427 USA
| | | | - Devin Leake
- Thermo Fisher Scientific, Dharmacon Products, 2650 Crescent Drive, Lafayette, CO 80026, USA
| | - Roger L. Kaspar
- Department of Pediatrics, Stanford School of Medicine, Stanford, CA 94305-5427 USA
- TransDerm Inc., 2161 Delaware Ave., Suite D, Santa Cruz, CA 95060 USA
| | - Christopher H. Contag
- Department of Pediatrics, Stanford School of Medicine, Stanford, CA 94305-5427 USA
- Molecular Imaging Program, Stanford University, Stanford, CA 94305-5427 USA
- Departments of Radiology, Microbiology, and Immunology, Stanford School of Medicine, Stanford, CA 94305-5427 USA
| | - Richard N. Zare
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, CA, 94305-5080 USA
- Address correspondence to
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24
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Abstract
RNA interference (RNAi) has been extensively employed for in vivo research since its use was first demonstrated in mammalian cells 10 years ago. Design rules have improved, and it is now routinely possible to obtain reagents that suppress expression of any gene desired. At the same time, increased understanding of the molecular basis of unwanted side effects has led to the development of chemical modification strategies that mitigate these concerns. Delivery remains the single greatest hurdle to widespread adoption of in vivo RNAi methods. However, exciting advances have been made and new delivery systems under development may help to overcome these barriers. This review discusses advances in RNAi biochemistry and biology that impact in vivo use and provides an overview of select publications that demonstrate interesting applications of these principles. Emphasis is placed on work with synthetic, small interfering RNAs (siRNAs) published since the first installment of this review which appeared in 2006.
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25
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González-González E, Kim YC, Speaker TJ, Hickerson RP, Spitler R, Birchall JC, Lara MF, Hu RH, Liang Y, Kirkiles-Smith N, Prausnitz MR, Milstone LM, Contag CH, Kaspar RL. Visualization of plasmid delivery to keratinocytes in mouse and human epidermis. Sci Rep 2011; 1:158. [PMID: 22355673 PMCID: PMC3240989 DOI: 10.1038/srep00158] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Accepted: 10/26/2011] [Indexed: 02/06/2023] Open
Abstract
The accessibility of skin makes it an ideal target organ for nucleic acid-based therapeutics; however, effective patient-friendly delivery remains a major obstacle to clinical utility. A variety of limited and inefficient methods of delivering nucleic acids to keratinocytes have been demonstrated; further advances will require well-characterized reagents, rapid noninvasive assays of delivery, and well-developed skin model systems. Using intravital fluorescence and bioluminescence imaging and a standard set of reporter plasmids we demonstrate transfection of cells in mouse and human xenograft skin using intradermal injection and two microneedle array delivery systems. Reporter gene expression could be detected in individual keratinocytes, in real-time, in both mouse skin as well as human skin xenografts. These studies revealed that non-invasive intravital imaging can be used as a guide for developing gene delivery tools, establishing a benchmark for comparative testing of nucleic acid skin delivery technologies.
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Affiliation(s)
- Emilio González-González
- Molecular Imaging Program at Stanford (MIPS), Stanford University School of Medicine, Stanford, CA 94305, USA
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Post-transcriptional gene silencing by RNA interference in non-mammalian vertebrate systems: Where do we stand? MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2011; 728:158-71. [DOI: 10.1016/j.mrrev.2011.09.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Revised: 09/02/2011] [Accepted: 09/06/2011] [Indexed: 12/20/2022]
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Colas J, Faure G, Saussereau E, Trudel S, Rabeh WM, Bitam S, Guerrera IC, Fritsch J, Sermet-Gaudelus I, Davezac N, Brouillard F, Lukacs GL, Herrmann H, Ollero M, Edelman A. Disruption of cytokeratin-8 interaction with F508del-CFTR corrects its functional defect. Hum Mol Genet 2011; 21:623-34. [PMID: 22038833 DOI: 10.1093/hmg/ddr496] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We have previously reported an increased expression of cytokeratins 8/18 (K8/K18) in cells expressing the F508del mutation of cystic fibrosis transmembrane conductance regulator (CFTR). This is associated with increased colocalization of CFTR and K18 in the vicinity of the endoplasmic reticulum, although this is reversed by treating cells with curcumin, resulting in the rescue of F508del-CFTR. In the present work, we hypothesized that (i) the K8/K18 network may interact physically with CFTR, and that (ii) this interaction may modify CFTR function. CFTR was immunoprecipitated from HeLa cells transfected with either wild-type (WT) CFTR or F508del-CFTR. Precipitates were subjected to 2D-gel electrophoresis and differential spots identified by mass spectrometry. K8 and K18 were found significantly increased in F508del-CFTR precipitates. Using surface plasmon resonance, we demonstrate that K8, but not K18, binds directly and preferentially to the F508del over the WT human NBD1 (nucleotide-binding domain-1). In vivo K8 interaction with F508del-CFTR was confirmed by proximity ligation assay in HeLa cells and in primary cultures of human respiratory epithelial cells. Ablation of K8 expression by siRNA in F508del-expressing HeLa cells led to the recovery of CFTR-dependent iodide efflux. Moreover, F508del-expressing mice topically treated with K8-siRNA showed restored nasal potential difference, equivalent to that of WT mice. These results show that disruption of F508del-CFTR and K8 interaction leads to the correction of the F508del-CFTR processing defect, suggesting a novel potential therapeutic target in CF.
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Affiliation(s)
- Julien Colas
- Faculté de Médecine Paris-Descartes, INSERM, U845, Paris, France
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D'Alessandro M, Coats SE, Jonkman MF, Jonkmann MF, Leigh IM, Lane EB. Keratin 14-null cells as a model to test the efficacy of gene therapy approaches in epithelial cells. J Invest Dermatol 2011; 131:1412-9. [PMID: 21326298 DOI: 10.1038/jid.2011.19] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Skin fragility disorders caused by keratin mutations are incurable, and a better understanding of their etiology is needed to find new ways to improve and treat these conditions. The best-studied skin fragility disorder is epidermolysis bullosa simplex (EBS), an autosomal dominant condition caused by mutations in keratin 5 (K5) or K14. To analyze disease mechanisms and develop gene therapy strategies, we have used keratinocyte cell lines derived from EBS patients as model systems. Here, we describe two cell lines established from EBS patients with K14-null mutations. We analyze the responses of these cells to stress assays previously shown to discriminate between wild-type and keratin-mutant keratinocytes, to directly evaluate the efficacy of rescuing K14-null cells by supplementation with wild-type K14 complementary DNA (cDNA). The K14-null cells show elevated levels of stress correlating with reduced normal keratin function. By transfecting wild-type K14 into these cells, we demonstrate "proof of principle" that an add-back approach can significantly rescue the normal keratinocyte behavior profile. These K14-null cell lines provide a disease model for studying the effects of keratin ablation in EBS patients and to test the efficacy of gene add-back and other therapy approaches in keratinocytes.
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Affiliation(s)
- Mariella D'Alessandro
- CR UK Cell Structure Research Group, Division of Molecular Medicine, College of Life Sciences, University of Dundee, Dundee, UK.
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Use of self-delivery siRNAs to inhibit gene expression in an organotypic pachyonychia congenita model. J Invest Dermatol 2011; 131:1037-44. [PMID: 21248764 DOI: 10.1038/jid.2010.426] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Although RNA interference offers therapeutic potential for treating skin disorders, delivery hurdles have hampered clinical translation. We have recently demonstrated that high pressure, resulting from intradermal injection of large liquid volumes, facilitated nucleic acid uptake by keratinocytes in mouse skin. Furthermore, similar intradermal injections of small interfering RNA (siRNA; TD101) into pachyonychia congenita (PC) patient foot lesions resulted in improvement. Unfortunately, the intense pain associated with hypodermic needle administration to PC lesions precludes this as a viable delivery option for this disorder. To investigate siRNA uptake by keratinocytes, an organotypic epidermal model, in which pre-existing endogenous gene or reporter gene expression can be readily monitored, was used to evaluate the effectiveness of "self-delivery" siRNA (i.e., siRNA chemically modified to enhance cellular uptake). In this model system, self-delivery siRNA treatment resulted in reduction of pre-existing fluorescent reporter gene expression under conditions in which unmodified controls had little or no effect. Additionally, treatment of PC epidermal equivalents with self-delivery "TD101" siRNA resulted in marked reduction of mutant keratin 6a mRNA with little or no effect on wild-type expression. These results indicate that chemical modification of siRNA may overcome certain limitations to transdermal delivery (specifically keratinocyte uptake) and may have clinical utility for inhibition of gene expression in the skin.
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30
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Hickerson RP, Leachman SA, Pho LN, Gonzalez-Gonzalez E, Smith FJD, McLean WHI, Contag CH, Leake D, Milstone LM, Kaspar RL. Development of quantitative molecular clinical end points for siRNA clinical trials. J Invest Dermatol 2010; 131:1029-36. [PMID: 21191405 DOI: 10.1038/jid.2010.372] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
RNA interference (RNAi) is an evolutionarily conserved mechanism that results in specific gene inhibition at the mRNA level. The discovery that short interfering RNAs (siRNAs) are selective, potent, and can largely avoid immune surveillance has resulted in keen interest to develop these inhibitors as therapeutics. A single nucleotide-specific siRNA (K6a_513a.12, also known as TD101) was recently evaluated in a phase 1b clinical trial for the rare skin disorder, pachyonychia congenita (PC). To develop a clinical trial molecular end point for this type of trial, methods were developed to: (1) isolate total RNA containing amplifiable mRNA from human skin and callus material; (2) quantitatively distinguish the single-nucleotide mutant mRNA from wild-type K6a mRNA in both patient-derived keratinocytes and patient callus; and (3) demonstrate that repeated siRNA treatment results in sustained inhibition of mutant K6a mRNA in patient-derived keratinocyte cultures. These methods allow noninvasive sampling and monitoring of gene expression from patient-collected shavings and may be useful in evaluating the effectiveness of RNAi-based therapeutics, including inhibitors that specifically target single-nucleotide mutations.
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31
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In vivo imaging of human and mouse skin with a handheld dual-axis confocal fluorescence microscope. J Invest Dermatol 2010; 131:1061-6. [PMID: 21191407 DOI: 10.1038/jid.2010.401] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Advancing molecular therapies for the treatment of skin diseases will require the development of new tools that can reveal spatiotemporal changes in the microanatomy of the skin and associate these changes with the presence of the therapeutic agent. For this purpose, we evaluated a handheld dual-axis confocal (DAC) microscope that is capable of in vivo fluorescence imaging of skin, using both mouse models and human skin. Individual keratinocytes in the epidermis were observed in three-dimensional image stacks after topical administration of near-infrared (NIR) dyes as contrast agents. This suggested that the DAC microscope may have utility in assessing the clinical effects of a small interfering RNA (siRNA)-based therapeutic (TD101) that targets the causative mutation in pachyonychia congenita (PC) patients. The data indicated that (1) formulated indocyanine green (ICG) readily penetrated hyperkeratotic PC skin and normal callused regions compared with nonaffected areas, and (2) TD101-treated PC skin revealed changes in tissue morphology, consistent with reversion to nonaffected skin compared with vehicle-treated skin. In addition, siRNA was conjugated to NIR dye and shown to penetrate through the stratum corneum barrier when topically applied to mouse skin. These results suggest that in vivo confocal microscopy may provide an informative clinical end point to evaluate the efficacy of experimental molecular therapeutics.
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Jacobson GB, Gonzalez-Gonzalez E, Spitler R, Shinde R, Leake D, Kaspar RL, Contag CH, Zare RN. Biodegradable Nanoparticles With Sustained Release of Functional siRNA in Skin. J Pharm Sci 2010; 99:4261-6. [DOI: 10.1002/jps.22147] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Kim HS, Cho HR, Choi SH, Woo JS, Moon WK. In vivo imaging of tumor transduced with bimodal lentiviral vector encoding human ferritin and green fluorescent protein on a 1.5T clinical magnetic resonance scanner. Cancer Res 2010; 70:7315-24. [PMID: 20823165 DOI: 10.1158/0008-5472.can-10-0241] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A combination of reporter genes for magnetic resonance imaging (MRI) and optical imaging can provide an additional level of noninvasive and quantitative information about biological processes occurring in deep tissues. We developed a bimodal lentiviral vector to monitor deep tissue events using MRI to detect myc-tagged human ferritin heavy chain (myc-hFTH) expression and fluorescence imaging to detect green fluorescent protein (GFP) expression. The transgene construct was stably transfected into MCF-7 and F-98 cells. After transplantation of the cells expressing myc-hFTH and GFP into mice or rats, serial MRI and fluorescence imaging were performed with a human wrist coil on a 1.5T MR scanner and optical imaging analyzer for 4 weeks. No cellular toxicity due to overexpression of myc-hFTH and GFP was observed in MTT and trypan blue exclusion assays. Iron accumulation was observed in myc-hFTH cells and tumors by Prussian blue staining and iron binding assays. The myc-hFTH cells and tumors had significantly lower signal intensities in T(2)-weighted MRI than mock-transfected controls (P ≤ 0.05). This is direct evidence that myc-hFTH expression can be visualized noninvasively with a 1.5T clinical MR scanner. This study shows that MRI and fluorescence imaging of transplanted cells at molecular and cellular levels can be performed simultaneously using our bimodal lentiviral vector system. Our techniques can be used to monitor tumor growth, metastasis, and regression during cell and gene-based therapy in deep tissues.
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Affiliation(s)
- Hoe Suk Kim
- Department of Radiology, Seoul National University Hospital and Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, South Korea
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El-Deeb IM, Yoo KH, Lee SH. ROS receptor tyrosine kinase: a new potential target for anticancer drugs. Med Res Rev 2010; 31:794-818. [PMID: 20687158 DOI: 10.1002/med.20206] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
ROS kinase is one of the last two remaining orphan receptor tyrosine kinases with an as yet unidentified ligand. The normal functions of human ROS kinase in different body tissues have not been fully identified so far. However, the ectopic expression, as well as the production of variable mutant forms of ROS kinase has been reported in a number of cancers, such as glioblastoma multiforme, and non-small cell lung cancer, suggesting a role for ROS kinase in deriving such tumors. It is thought also that c-ROS gene may have a role in some cardiovascular diseases, and the fact that homozygous male mice targeted against c-ROS gene are healthy but infertile, has inspired researchers to think about ROS inhibition as a method for development of new male contraceptives. The recent discovery of new selective and potent inhibitors for ROS kinase, along with the development of new specific diagnostic methods for the detection of ROS fusion proteins, raises the importance of using these selective inhibitors for targeting ROS mutations as a new method for treatment of cancers harboring such genes. This review focuses on the ectopic expression of ROS and its fusion proteins in different cancer types and highlights the importance of targeting these proteins for treatment of substantial cancers. It describes also the recent advances in the field of ROS kinase inhibition, and the potential clinical applications of ROS kinase inhibitors.
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Affiliation(s)
- Ibrahim Mustafa El-Deeb
- Life/Health Division, Korea Institute of Science and Technology, Cheongryang, Seoul, Republic of Korea; Department of Biomolecular Science, University of Science and Technology, Yuseong-gu, Daejeon, Republic of Korea
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35
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Silencing of reporter gene expression in skin using siRNAs and expression of plasmid DNA delivered by a soluble protrusion array device (PAD). Mol Ther 2010; 18:1667-74. [PMID: 20571543 DOI: 10.1038/mt.2010.126] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Despite rapid progress in the development of potent and selective small interfering RNA (siRNA) agents for skin disorders, translation to the clinic has been hampered by the lack of effective, patient-friendly delivery technologies. The stratum corneum poses a formidable barrier to efficient delivery of large and/or charged macromolecules including siRNAs. Intradermal siRNA injection results in effective knockdown of targeted gene expression but is painful and the effects are localized to the injection site. The use of microneedle arrays represents a less painful delivery method and may have utility for the delivery of nucleic acids, including siRNAs. For this purpose, we developed a loadable, dissolvable protrusion array device (PAD) that allows skin barrier penetration. The PAD tips dissolve upon insertion, forming a gel-like plug that releases functional cargo. PAD-mediated delivery of siRNA (modified for enhanced stability and cellular uptake) resulted in effective silencing of reporter gene expression in a transgenic reporter mouse model. PAD delivery of luciferase reporter plasmids resulted in expression in cells of the ear, back, and footpad skin as assayed by intravital bioluminescence imaging. These results support the use of PADs for delivery of functional nucleic acids to cells in the skin with an efficiency that may support clinical translation.
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González-González E, Ra H, Spitler R, Hickerson RP, Contag CH, Kaspar RL. Increased interstitial pressure improves nucleic acid delivery to skin enabling a comparative analysis of constitutive promoters. Gene Ther 2010; 17:1270-8. [PMID: 20463756 DOI: 10.1038/gt.2010.74] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Nucleic acid-based therapies hold great promise for treatment of skin disorders if delivery challenges can be overcome. To investigate one mechanism of nucleic acid delivery to keratinocytes, a fixed mass of expression plasmid was intradermally injected into mouse footpads in different volumes, and reporter expression was monitored by intravital imaging or skin sectioning. Reporter gene expression increased with higher delivery volumes, suggesting that pressure drives nucleic acid uptake into cells after intradermal injections similar to previously published studies for muscle and liver. For spatiotemporal analysis of reporter gene expression, a dual-axis confocal (DAC) fluorescence microscope was used for intravital imaging following intradermal injections. Individual keratinocytes expressing hMGFP were readily visualized in vivo and initially appeared to preferentially express in the stratum granulosum and subsequently migrate to the stratum corneum over time. Fluorescence microscopy of frozen skin sections confirmed the patterns observed by intravital imaging. Intravital imaging with the DAC microscope is a noninvasive method for probing spatiotemporal control of gene expression and should facilitate development and testing of new nucleic acid delivery technologies.
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Affiliation(s)
- E González-González
- Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, CA, USA
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37
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Ra H, Gonzalez-Gonzalez E, Smith BR, Gambhir SS, Kino GS, Solgaard O, Kaspar RL, Contag CH. Assessing delivery and quantifying efficacy of small interfering ribonucleic acid therapeutics in the skin using a dual-axis confocal microscope. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:036027. [PMID: 20615029 PMCID: PMC2904026 DOI: 10.1117/1.3432627] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Transgenic reporter mice and advances in imaging instrumentation are enabling real-time visualization of cellular mechanisms in living subjects and accelerating the development of novel therapies. Innovative confocal microscope designs are improving their utility for microscopic imaging of fluorescent reporters in living animals. We develop dual-axis confocal (DAC) microscopes for such in vivo studies and create mouse models where fluorescent proteins are expressed in the skin for the purpose of advancing skin therapeutics and transdermal delivery tools. Three-dimensional image volumes, through the different skin compartments of the epidermis and dermis, can be acquired in several seconds with the DAC microscope in living mice, and are comparable to histologic analyses of reporter protein expression patterns in skin sections. Intravital imaging with the DAC microscope further enables visualization of green fluorescent protein (GFP) reporter gene expression in the skin over time, and quantification of transdermal delivery of small interfering RNA (siRNA) and therapeutic efficacy. Visualization of transdermal delivery of nucleic acids will play an important role in the development of innovative strategies for treating skin pathologies.
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Affiliation(s)
- Hyejun Ra
- Stanford University, Department of Electrical Engineering, Ginzton Laboratory, Stanford, California 94305, USA.
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Geusens B, Sanders N, Prow T, Van Gele M, Lambert J. Cutaneous short-interfering RNA therapy. Expert Opin Drug Deliv 2010; 6:1333-49. [PMID: 19941411 DOI: 10.1517/17425240903304032] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Since the 1990s, RNA interference (RNAi) has become a major subject of interest, not only as a tool for biological research, but also, more importantly, as a therapeutic approach for gene-related diseases. The use of short-interfering RNAs (siRNAs) for the sequence-specific knockdown of disease-causing genes has led to numerous preclinical and even a few clinical studies. Applications for cutaneous delivery of therapeutic siRNA are now emerging owing to a strong demand for effective treatments of various cutaneous disorders. Although successful studies have been performed using several different delivery techniques, most of these techniques encounter limitations for translation to the clinic with regards to patient compliance. This review describes the principal findings and applications in cutaneous RNAi therapy and focuses on the promises and pitfalls of the delivery systems.
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Affiliation(s)
- B Geusens
- Ghent University Hospital, Department of Dermatology, De Pintelaan 185, B-9000 Ghent, Belgium.
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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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40
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First-in-human mutation-targeted siRNA phase Ib trial of an inherited skin disorder. Mol Ther 2009; 18:442-6. [PMID: 19935778 DOI: 10.1038/mt.2009.273] [Citation(s) in RCA: 209] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The rare skin disorder pachyonychia congenita (PC) is an autosomal dominant syndrome that includes a disabling plantar keratoderma for which no satisfactory treatment is currently available. We have completed a phase Ib clinical trial for treatment of PC utilizing the first short-interfering RNA (siRNA)-based therapeutic for skin. This siRNA, called TD101, specifically and potently targets the keratin 6a (K6a) N171K mutant mRNA without affecting wild-type K6a mRNA. The safety and efficacy of TD101 was tested in a single-patient 17-week, prospective, double-blind, split-body, vehicle-controlled, dose-escalation trial. Randomly assigned solutions of TD101 or vehicle control were injected in symmetric plantar calluses on opposite feet. No adverse events occurred during the trial or in the 3-month washout period. Subjective patient assessment and physician clinical efficacy measures revealed regression of callus on the siRNA-treated, but not on the vehicle-treated foot. This trial represents the first time that siRNA has been used in a clinical setting to target a mutant gene or a genetic disorder, and the first use of siRNA in human skin. The callus regression seen on the patient's siRNA-treated foot appears sufficiently promising to warrant additional studies of siRNA in this and other dominant-negative skin diseases.
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