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Abstract
CD28 is one of the main costimulatory receptors responsible for the proper activation of T lymphocytes. We have isolated two aptamers that bind to the CD28 receptor. As a monomer, one of them interfered with the binding of CD28 to its ligand (B7), precluding the costimulatory signal, whereas the other one was inactive. However, dimerization of any of the anti-CD28 aptamers was sufficient to provide an artificial costimulatory signal. No antibody has featured a dual function (i.e., the ability to work as agonist and antagonist) to date. Two different agonistic structures were engineered for each anti-CD28 aptamer. One showed remarkably improved costimulatory properties, surpassing the agonistic effect of an anti-CD28 antibody. Moreover, we showed in vivo that the CD28 agonistic aptamer is capable of enhancing the cellular immune response against a lymphoma idiotype and of prolonging survival of mice which receive the aptamer together with an idiotype vaccine. The CD28 aptamers described in this work could be used to modulate the immune response either blocking the interaction with B7 or enhancing vaccine-induced immune responses in cancer immunotherapy.Molecular Therapy - Nucleic Acids (2013) 2, e98; doi:10.1038/mtna.2013.26; published online 11 June 2013.
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52
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Kim S, Matsumoto M, Chiba K. Liquid-phase RNA synthesis by using alkyl-chain-soluble support. Chemistry 2013; 19:8615-20. [PMID: 23657898 DOI: 10.1002/chem.201300655] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Indexed: 11/09/2022]
Abstract
Recent progress in the RNA therapeutics has increased demand for the synthesis of large quantities of oligoribonucleotides. The assembly of RNA oligomers relies mainly on solid-phase approaches. These allow rapid product purification and the ability to drive a target reaction to completion through the use of excess reagents. Despite the known advantages of solid-phase synthesis, some issues in the process remain to be addressed, such as low and limited scale, reagent accessibility, and the use of a very large excess of reagents. Herein, we report a highly efficient and practical method of liquid-phase synthesis of RNA oligomers by using alkyl-chain-soluble support. We demonstrate the utility of the liquid-phase method through 21-mer RNA synthesis on a gram scale.
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Affiliation(s)
- Shokaku Kim
- Laboratory of Bio-organic Chemistry, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
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53
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Cleavage-based signal amplification of RNA. Nat Commun 2013; 4:1493. [PMID: 23422661 DOI: 10.1038/ncomms2492] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Accepted: 01/15/2013] [Indexed: 01/04/2023] Open
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54
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Recent Advances in Ribonucleic Acid Interference (RNAi). NATIONAL ACADEMY SCIENCE LETTERS 2013. [DOI: 10.1007/s40009-012-0102-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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55
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TLR9-mediated siRNA delivery for targeting of normal and malignant human hematopoietic cells in vivo. Blood 2013; 121:1304-15. [PMID: 23287859 DOI: 10.1182/blood-2012-07-442590] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
STAT3 operates in both cancer cells and tumor-associated immune cells to promote cancer progression. As a transcription factor, it is a highly desirable but difficult target for pharmacologic inhibition. We have recently shown that the TLR9 agonists CpG oligonucleotides can be used for targeted siRNA delivery to mouse immune cells. In the present study, we demonstrate that a similar strategy allows for targeted gene silencing in both normal and malignant human TLR9(+) hematopoietic cells in vivo. We have developed new human cell-specific CpG(A)-STAT3 siRNA conjugates capable of inducing TLR9-dependent gene silencing and activation of primary immune cells such as myeloid dendritic cells, plasmacytoid dendritic cells, and B cells in vitro. TLR9 is also expressed by several human hematologic malignancies, including B-cell lymphoma, multiple myeloma, and acute myeloid leukemia. We further demonstrate that oncogenic proteins such as STAT3 or BCL-X(L) are effectively knocked down by specific CpG(A)-siRNAs in TLR9(+) hematologic tumor cells in vivo. Targeting survival signaling using CpG(A)-siRNAs inhibits the growth of several xenotransplanted multiple myeloma and acute myeloid leukemia tumors. CpG(A)-STAT3 siRNA is immunostimulatory and nontoxic for normal human leukocytes in vitro. The results of the present study show the potential of using tumoricidal/immunostimulatory CpG-siRNA oligonucleotides as a novel 2-pronged therapeutic strategy for hematologic malignancies.
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56
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Abstract
The rapid development of therapeutic oligonucleotides (ONs) has created a need for in-depth characterization of ONs, beyond previous requirements. The natural migration to LC-MS requires the use of chromatography with MS-compatible eluents to introduce the large, highly charged biopolymers into the mass spectrometer. Most frequently this employs ion-pair reversed-phase liquid chromatography, which may leave gaps in the characterization, but these can be filled with the use of high-resolution ion-exchange chromatography. Several classes of isobaric isomers are among the impurities that will require further separation prior to MS analysis. This review shows how the use of ion exchange as an additional orthogonal analytical method can be used as standalone or interfaced with MS to achieve the highest possible analytical coverage in the characterization and quantification of impurities present in single- and double-stranded ON formulations. Some of these techniques have been in use for some time and the importance of others is just being recognized.
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57
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Abstract
A substantial fraction of glaucoma has a genetic basis. About 5% of primary open angle glaucoma (POAG) is currently attributed to single-gene or Mendelian forms of glaucoma (ie glaucoma caused by mutations in myocilin or optineurin). Mutations in these genes have a high likelihood of leading to glaucoma and are rarely seen in normal subjects. Other cases of POAG have a more complex genetic basis and are caused by the combined effects of many genetic and environmental risk factors, each of which do not act alone to cause glaucoma. These factors are more frequently detected in patients with POAG, but are also commonly observed in normal subjects. Additional genes that may be important in glaucoma pathogenesis have been investigated using quantitative traits approaches. Such studies have begun to identify genes that control the magnitude of important quantitative features of glaucoma that may also be important risk factors for POAG, such as central corneal thickness. Each of these different approaches to study glaucoma genetics is providing new insights into the pathogenesis of POAG.
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58
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Cho IM, Kazakov SA, Gopalan V. Evidence for recycling of external guide sequences during cleavage of bipartite substrates in vitro by reconstituted archaeal RNase P. J Mol Biol 2011; 405:1121-7. [PMID: 21144851 PMCID: PMC3025773 DOI: 10.1016/j.jmb.2010.11.056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Revised: 11/25/2010] [Accepted: 11/30/2010] [Indexed: 11/18/2022]
Abstract
RNA-mediated RNA cleavage events are being increasingly exploited to disrupt RNA function, an important objective in post-genomic biology. RNase P, a ribonucleoprotein enzyme that catalyzes the removal of 5'-leaders from precursor tRNAs, has previously been utilized for sequence-specific cleavage of cellular RNAs. In one of these strategies, borne out in bacterial and mammalian cell culture, an external guide sequence (EGS) RNA base-paired to a target RNA makes the latter a substrate for endogenous RNase P by rendering the bipartite target RNA-EGS complex a precursor tRNA structural mimic. In this study, we first obtained evidence that four different mesophilic and thermophilic archaeal RNase P holoenzymes, reconstituted in vitro using their respective constituent RNA and protein subunits, recognize and cleave such substrate-EGS complexes. We further demonstrate that these EGSs engage in multiple rounds of substrate recognition while assisting archaeal RNase P-mediated cleavage of a target RNA in vitro. Taken together, the EGS-based approach merits consideration as a gene knockdown tool in archaea.
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Affiliation(s)
- I-Ming Cho
- Department of Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | | | - Venkat Gopalan
- Department of Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
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59
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Oligomeric nucleic acids as antivirals. Molecules 2011; 16:1271-96. [PMID: 21278679 PMCID: PMC6259927 DOI: 10.3390/molecules16021271] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 01/12/2011] [Accepted: 01/25/2011] [Indexed: 02/07/2023] Open
Abstract
Based on the natural functions and chemical characteristics of nucleic acids, a variety of novel synthetic drugs and tools to explore biological systems have become available in recent years. To date, a great number of antisense oligonucleotides, RNA interference-based tools, CpG-containing oligonucleotides, catalytic oligonucleotides, decoys and aptamers has been produced synthetically and applied successfully for understanding and manipulating biological processes and in clinical trials to treat a variety of diseases. Their versatility and potency make them equally suited candidates for fighting viral infections. Here, we describe the different types of nucleic acid-based antivirals, their mechanism of action, their advantages and limitations, and their future prospects.
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60
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Molecular Genetics of Corneal Disease. Cornea 2011. [DOI: 10.1016/b978-0-323-06387-6.00019-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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61
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Vizirianakis IS. Nanomedicine and personalized medicine toward the application of pharmacotyping in clinical practice to improve drug-delivery outcomes. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2010; 7:11-7. [PMID: 21094279 DOI: 10.1016/j.nano.2010.11.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 10/21/2010] [Accepted: 11/02/2010] [Indexed: 12/15/2022]
Abstract
UNLABELLED Recent technological advances in nanomedicine and nanotechnology in parallel with knowledge accumulated from the clinical translation of disease- and drug-related genomic data have created fertile ground for personalized medicine to emerge as the new direction in diagnosis and drug therapy. To this end, the development of sophisticated nano-based systems for targeted drug delivery, along with the advent of pharmacogenomics, moves the drug-prescription process toward pharmacotyping, e.g., the individualized adjustment of drug selection and dosage. However, the clinical validity and utility of pharmacogenomic testing must be demonstrated by cost-effectiveness analysis and establishment of clinical-practice reimbursement codes. Within this framework, and to achieve major benefits for all patients worldwide, a multidisciplinary scientific and technological infrastructure has to be organized in the healthcare system to address better the issues affecting regulatory environment, clinical pharmacology guidelines, education, bioethics and genomics data dissemination. FROM THE CLINICAL EDITOR Individualized pharmacotyping, patient and disease-specific delivery of drugs, combining nanotechnology and pharmagenomics-based approaches would result in much more specific and efficient treatment of a variety of illnesses. While this clearly is one of the main cornerstones of individualized medicine; the cost effective integration of this complex technology is far from trivial, as discussed in details in this opinion paper.
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Affiliation(s)
- Ioannis S Vizirianakis
- Laboratory of Pharmacology, Department of Pharmaceutical Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece.
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62
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Wan Y, Kim YT, Li N, Cho SK, Bachoo R, Ellington AD, Iqbal SM. Surface-Immobilized Aptamers for Cancer Cell Isolation and Microscopic Cytology. Cancer Res 2010; 70:9371-80. [DOI: 10.1158/0008-5472.can-10-0568] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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63
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Aubin-Tam ME, Appleyard DC, Ferrari E, Garbin V, Fadiran OO, Kunkel J, Lang MJ. Adhesion through single peptide aptamers. J Phys Chem A 2010; 115:3657-64. [PMID: 20795685 DOI: 10.1021/jp1031493] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Aptamer and antibody mediated adhesion is central to biological function and is valuable in the engineering of "lab on a chip" devices. Single molecule force spectroscopy using optical tweezers enables direct nonequilibrium measurement of these noncovalent interactions for three peptide aptamers selected for glass, polystyrene, and carbon nanotubes. A comprehensive examination of the strong attachment between antifluorescein 4-4-20 and fluorescein was also carried out using the same assay. Bond lifetime, barrier width, and free energy of activation are extracted from unbinding histogram data using three single molecule pulling models. The evaluated aptamers appear to adhere stronger than the fluorescein antibody under no- and low-load conditions, yet weaker than antibodies at loads above ∼25 pN. Comparison to force spectroscopy data of other biological linkages shows the diversity of load dependent binding and provides insight into linkages used in biological processes and those designed for engineered systems.
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Affiliation(s)
- Marie-Eve Aubin-Tam
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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64
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Peptide aptamer: a powerful potential tool in plant functional genomics. YI CHUAN = HEREDITAS 2010; 32:548-54. [DOI: 10.3724/sp.j.1005.2010.00548] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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65
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Mammalian cell transfection: the present and the future. Anal Bioanal Chem 2010; 397:3173-8. [PMID: 20549496 PMCID: PMC2911531 DOI: 10.1007/s00216-010-3821-6] [Citation(s) in RCA: 375] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Revised: 04/28/2010] [Accepted: 05/03/2010] [Indexed: 01/23/2023]
Abstract
Transfection is a powerful analytical tool enabling study of the function of genes and gene products in cells. The transfection methods are broadly classified into three groups; biological, chemical, and physical. These methods have advanced to make it possible to deliver nucleic acids to specific subcellular regions of cells by use of a precisely controlled laser-microcope system. The combination of point-directed transfection and mRNA transfection is a new way of studying the function of genes and gene products. However, each method has its own advantages and disadvantages so the optimum method depends on experimental design and objective.
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66
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Yang G, Withers SG. Ultrahigh-throughput FACS-based screening for directed enzyme evolution. Chembiochem 2010; 10:2704-15. [PMID: 19780076 DOI: 10.1002/cbic.200900384] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Directed enzyme evolution has proven to be a powerful tool for improving a range of properties of enzymes through consecutive rounds of diversification and selection. However, its success depends heavily on the efficiency of the screening strategy employed. Fluorescence-activated cell sorting (FACS) has recently emerged as a powerful tool for screening enzyme libraries due to its high sensitivity and its ability to analyze as many as 10(8) mutants per day. Applications of FACS screening have allowed the isolation of enzyme variants with significantly improved activities, altered substrate specificities, or even novel functions. This review discusses FACS-based screening for enzymatic activity and its potential application for the directed evolution of enzymes, ribozymes, and catalytic antibodies.
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Affiliation(s)
- Guangyu Yang
- Centre for High-Throughput Biology (CHiBi) and Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, B.C. V6T 1Z1, Canada
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67
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Suzuki M, Zheng X, Zhang X, Ichim TE, Beduhn ME, Min W. Oligonucleotide based-strategies for allergy with special reference to siRNA. Expert Opin Biol Ther 2010; 9:441-50. [PMID: 19344281 DOI: 10.1517/14712590902841924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Allergic diseases are a significant global health care problem. Current pharmacological approaches address symptoms but do not alter the underlying immune dysregulation. Current allergen-specific immunotherapy has several drawbacks. Therefore, approaches that attenuate allergic responses safely and effectively at the level of upstream causative events are desirable. Oligonuleotide-based therapies [CpG DNA, antisense oligonucleotides, and small interfering RNA (siRNA)] are promising approaches. OBJECTIVE/METHODS We review developments in oligonucleotide-based therapies and the potential of siRNA for treating allergy. RESULTS/CONCLUSIONS Strategies with oligonucleotides basically aim to reduce T helper type 2 (Th2) responses. It is controversial whether the reduction of Th2 responses does, in fact, attenuate allergic diseases. Increased understanding of allergic mechanisms will enhance the efficacy of oligonucleotide-based therapy.
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Affiliation(s)
- Motohiko Suzuki
- University of Western Ontario, University Hospital C9 - 136, Department of Surgery, London, Ontario, N6A 5A5, Canada
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68
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Abstract
Adoptive transfer of T cells with restricted tumor specificity provides a promising approach to immunotherapy of cancers. However, the isolation of autologous cytotoxic T cells that recognize tumor-associated antigens is time consuming and fails in many instances. Alternatively, gene modification with tumor antigen-specific T-cell receptors (TCR) or chimeric antigen receptors (CARs) can be used to redirect the specificity of large numbers of immune cells toward the malignant cells. Chimeric antigen receptors are composed of the single-chain variable fragment (scFv) of a tumor-recognizing antibody cloned in frame with human T-cell signaling domains (e.g., CD3zeta, CD28, OX40, 4-1BB), thus combining the specificity of antibodies with the effector functions of cytotoxic T cells. Upon antigen binding, the intracellular signaling domains of the CAR initiate cellular activation mechanisms including cytokine secretion and cytolysis of the antigen-positive target cell.In this chapter, we provide detailed protocols for large-scale ex vivo expansion of T cells and manufacturing of medium-scale batches of CAR-expressing T cells for translational research by mRNA electroporation. An anti-CD19 chimeric receptor for the targeting of leukemias and lymphomas was used as a model system. We are currently scaling up the protocols to adapt them to cGMP production of a large number of redirected T cells for clinical applications.
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Affiliation(s)
- Hilde Almåsbak
- Department of Immunology, Radiumhospitalet-Rikshospitalet, University Hospital, Oslo, Norway
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69
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Song MS, Lee SW. RNA Mapping of Mutant Myotonic Dystrophy Protein Kinase 3'-Untranslated Region Transcripts. Genomics Inform 2009. [DOI: 10.5808/gi.2009.7.4.181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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70
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Schmitt M, Casalegno-Garduño R, Xu X, Schmitt A. Peptide vaccines for patients with acute myeloid leukemia. Expert Rev Vaccines 2009; 8:1415-25. [PMID: 19803762 DOI: 10.1586/erv.09.90] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The majority of patients with acute myeloid leukemia (AML) under 60 years of age reach a complete hematological remission after intensive chemotherapy. However, only 20-40% of all patients with AML achieve a disease-free survival of more than 5 years. The graft-versus-leukemia effect observed after allogeneic stem cell transplantation and donor lymphocyte infusions strongly suggests that T lymphocytes play a major role in the rejection of leukemic cells. Vaccination with leukemia-associated antigen (LAA) peptides might constitute a way to augment the graft-versus-leukemia effect. Peptide vaccination causes no major side effects, which is of particular note as most AML patients are people over 60 years of age, often suffering from concomitant disease. This review summarizes approaches to define appropriate LAAs as targets of a T-cell-based vaccine immunotherapy. Current clinical LAA peptide vaccination protocols targeting Wilms' tumor gene, proteinase-3 and the receptor for hyaluronan-mediated motility are reviewed and an outlook to dendritic cells, adjuvants and short oligodenucleotides is given.
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Affiliation(s)
- Michael Schmitt
- Head of Clinical Stem Cell Transplantation and Cellular Therapy, Department of Internal Medicine III, University of Rostock, Ernst-Heydemann-Str. 6, 18057 Rostock, Germany.
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71
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Gene silencing in human embryonic stem cells by RNA interference. Biochem Biophys Res Commun 2009; 390:1106-10. [DOI: 10.1016/j.bbrc.2009.10.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2009] [Accepted: 10/08/2009] [Indexed: 12/27/2022]
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72
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Mekkawy AH, Morris DL, Pourgholami MH. Urokinase plasminogen activator system as a potential target for cancer therapy. Future Oncol 2009; 5:1487-99. [DOI: 10.2217/fon.09.108] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Proteolysis of extracellular matrix (ECM) and basement membrane is an essential mechanism used by cancer cells for their invasion and metastasis. The ECM proteinases are divided into three groups: metalloproteinases, cysteine proteinases and serine proteinases. The urokinase plasminogen activator (uPA) system is one of the serine proteinase systems involved in ECM degradation. Members of this system, including uPA and its receptor (uPAR), are overexpressed in several malignant tumors. This system plays a major role in adhesion, migration, invasion and metastasis of cancer cells, thus making it an important target for anticancer drug therapy. Several strategies, including the use of antisense oligodeoxynucleotides, ribozymes, DNAzyme, RNAi, uPA inhibitors, soluble uPAR, catalytically inactive uPA fragments, synthetic peptides and synthetic hybrids are under study, as they interfere with the expression and/or activity of uPA or uPAR in tumor cells. Herein, we discuss the various pharmaceutical strategies under investigation to combat the uPA activity in cancer.
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Affiliation(s)
| | | | - Mohammad H Pourgholami
- Cancer Research Laboratories, University of New South Wales, Department of Surgery, St George Hospital (SESIAHS), Sydney, NSW 2217, Australia
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73
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Li L, Liu LN, Feller S, Allen C, Shivakumar R, Fratantoni J, Wolfraim LA, Fujisaki H, Campana D, Chopas N, Dzekunov S, Peshwa M. Expression of chimeric antigen receptors in natural killer cells with a regulatory-compliant non-viral method. Cancer Gene Ther 2009; 17:147-54. [PMID: 19745843 DOI: 10.1038/cgt.2009.61] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Natural killer (NK) cells hold promise for cancer therapy. NK cytotoxicity can be enhanced by expression of chimeric antigen receptors that re-direct specificity toward target cells by engaging cell surface molecules expressed on target cells. We developed a regulatory-compliant, scalable non-viral approach to engineer NK cells to be target-specific based on transfection of mRNA encoding chimeric receptors. Transfection of eGFP mRNA into ex vivo expanded NK cells (N=5) or purified unstimulated NK cells from peripheral blood (N=4) resulted in good cell viability with eGFP expression in 85+/-6% and 86+/-4%, 24 h after transfection, respectively. An mRNA encoding a receptor directed against CD19 (anti-CD19-BB-z) was also transfected into NK cells efficiently. Ex vivo expanded and purified unstimulated NK cells expressing anti-CD19-BB-z exhibited enhanced cytotoxicity against CD19(+) target cells resulting in > or =80% lysis of acute lymphoblastic leukemia and B-lineage chronic lymphocytic leukemia cells at effector target ratios lower than 10:1. The target-specific cytotoxicity for anti-CD19-BB-z mRNA-transfected NK cells was observed as early as 3 h after transfection and persisted for up to 3 days. The method described here should facilitate the clinical development of NK-based antigen-targeted immunotherapy for cancer.
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Affiliation(s)
- L Li
- MaxCyte Inc, Gaithersburg, MD 20878, USA.
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74
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Ahn DG, Jeon IJ, Kim JD, Song MS, Han SR, Lee SW, Jung H, Oh JW. RNA aptamer-based sensitive detection of SARS coronavirus nucleocapsid protein. Analyst 2009; 134:1896-901. [PMID: 19684916 DOI: 10.1039/b906788d] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Severe acute respiratory syndrome coronavirus (SARS-CoV) is the etiological agent of a newly emerged disease SARS. The SARS-CoV nucleocapsid (N) protein is one of the most abundant structural proteins and serves as a diagnostic marker for accurate and sensitive detection of the virus. Using a SELEX (systematic evolution of ligand by exponential enrichment) procedure and recombinant N protein, we selected a high-affinity RNA aptamer capable of binding to N protein with a dissociation constant of 1.65 nM. Electrophoretic mobility shift assays and RNA competition experiments showed that the selected aptamer recognized selectively the C-terminal region of N protein with high specificity. Using a chemiluminescence immunosorbent assay and a nanoarray aptamer chip with the selected aptamer as an antigen-capturing agent, we could sensitively detect N protein at a concentration as low as 2 pg/ml. These aptamer-antibody hybrid immunoassays may be useful for rapid, sensitive detection of SARS-CoV N protein.
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Affiliation(s)
- Dae-Gyun Ahn
- Department of Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
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75
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Schmidt SM, König T, Bringmann A, Held S, von Schwarzenberg K, Heine A, Holderried TAW, Stevanovic S, Grünebach F, Brossart P. Characterization of BAX inhibitor-1 as a novel leukemia-associated antigen. Leukemia 2009; 23:1818-24. [PMID: 19609282 DOI: 10.1038/leu.2009.138] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Using dendritic cells (DCs) electroporated with whole RNA isolated from blasts of a patient with acute myeloid leukemia (AML), we were able to generate leukemia-specific cytotoxic T lymphocytes (CTLs) capable of recognizing the leucemic cells. To identify T-cell epitopes mediating lysis of malignant cells, peptides were eluted from the patient's blasts and analyzed by mass spectrometry (LC/MS)-based peptide sequencing. Using this approach, an HLA-A24-binding peptide derived from Bax inhibitor-1 (BI-1), a regulator of apoptosis pathways, was identified as an epitope recognized by the generated CTLs. To further characterize this novel antigenic peptide, CTLs were induced using DCs electroporated with RNA coding for BI-1 or pulsed with the cognate peptide. These CTLs generated from healthy donors in vitro efficiently lysed the patient's blasts as well as other HLA-matched leukemic cells. In conclusion, we identified a BI-1 peptide as a novel immunogenic tumor-associated antigen (TAA) in AML. In vitro induction of BI-1-specific CTLs by RNA transfection or pulsing of DCs with the synthetically generated peptide was a feasible and highly effective method to generate leukemia-specific CTLs. As BI-1 is (over-) expressed in a broad variety of malignancies, it may represent an interesting novel TAA in the context of cancer vaccines.
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Affiliation(s)
- S M Schmidt
- Department of Hematology, Oncology, Rheumatology and Immunology, University of Tübingen, Tübingen, Germany
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76
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Abstract
Over the past decade, single-molecule fluorescence studies have elucidated the structure-function relationship of RNA molecules. The real-time observation of individual RNAs by single-molecule fluorescence has unveiled the dynamic behavior of complex RNA systems in unprecedented detail, revealing the presence of transient intermediate states and their kinetic pathways. This review provides an overview of how single-molecule fluorescence has been used to explore the dynamics of RNA folding and catalysis.
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Affiliation(s)
| | - David Rueda
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI 48202, USA
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77
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An L, Liu L, Wang S, Bazan G. An Optical Approach for Drug Screening Based on Light-Harvesting Conjugated Polyelectrolytes. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200900758] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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78
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An L, Liu L, Wang S, Bazan G. An Optical Approach for Drug Screening Based on Light-Harvesting Conjugated Polyelectrolytes. Angew Chem Int Ed Engl 2009; 48:4372-5. [DOI: 10.1002/anie.200900758] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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79
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Effects of antiatherosclerosis in carotid artery by RNAi-mediated silencing of MCP-1 expression. Ann Vasc Surg 2009; 23:652-62. [PMID: 19467827 DOI: 10.1016/j.avsg.2009.01.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2008] [Revised: 01/15/2009] [Accepted: 01/26/2009] [Indexed: 11/21/2022]
Abstract
BACKGROUND Our objective was to identify the effects of MCP-1 siRNA in vivo transfection in an atherosclerosis model on local expression of MCP-1 and pathogenesis of atherosclerosis. METHODS Carotid atherosclerosis was induced in 28 New Zealand white rabbits. Rabbits were divided into three groups randomly: RNAi group, model group, and blank plasmid group. siRNA-expressing vector was transfected to blood vessels by liposomes. The carotid arteries were processed for morphological evaluation. Local expression of MCP-1 was detected by immunohistochemistry, RT-PCR, and Western blot. RESULTS On hematoxylin and eosin-stained sections, partial endothelial cells detached while intimae were less thickened in the RNAi group compared to the model and blank plasmid groups; the I:M ratio was significantly reduced to 1.46 in the RNAi group compared to the model and blank plasmid groups (5.55 and 5.27, respectively). The results of immunohistochemistry showed that MCP-1 expression was less colorized and less positive in the RNAi group. RT-PCR and Western blot showed reduced expression in the RNAi group than in the model and blank plasmid groups. There were highly positive correlations between semiquantitative RT-PCR and the I:M ratio (r = 0.968). CONCLUSION Expression of MCP-1 was successfully inhibited by transfecting MCP-1 siRNA expression plasmid to the carotid artery, and the progression of atherosclerosis was restricted by RNAi-mediated silencing of MCP-1 expression.
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80
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Affiliation(s)
- Juewen Liu
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
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81
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Liu Y, Kuan CT, Mi J, Zhang X, Clary BM, Bigner DD, Sullenger BA. Aptamers selected against the unglycosylated EGFRvIII ectodomain and delivered intracellularly reduce membrane-bound EGFRvIII and induce apoptosis. Biol Chem 2009; 390:137-44. [PMID: 19040357 DOI: 10.1515/bc.2009.022] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Epidermal growth factor receptor variant III (EGFRvIII) is a glycoprotein uniquely expressed in glioblastoma, but not in normal brain tissues. To develop targeted therapies for brain tumors, we selected RNA aptamers against the histidine-tagged EGFRvIII ectodomain, using an Escherichia coli system for protein expression and purification. Representative aptamer E21 has a dissociation constant (Kd) of 33x10(-9) m, and exhibits high affinity and specificity for EGFRvIII in ELISA and surface plasmon resonance assays. However, selected aptamers cannot bind the same protein expressed from eukaryotic cells because glycosylation, a post-translational modification present only in eukaryotic systems, significantly alters the structure of the target protein. By transfecting EGFRvIII aptamers into cells, we find that membrane-bound, glycosylated EGFRvIII is reduced and the percentage of cells undergoing apoptosis is increased. We postulate that transfected aptamers can interact with newly synthesized EGFRvIII, disrupt proper glycosylation, and reduce the amount of mature EGFRvIII reaching the cell surface. Our work establishes the feasibility of disrupting protein post-translational modifications in situ with aptamers. This finding is useful for elucidating the function of proteins of interest with various modifications, as well as dissecting signal transduction pathways.
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Affiliation(s)
- Yingmiao Liu
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
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82
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Wang J, Mansfield SG, Cote CA, Jiang PD, Weng K, Amar MJA, Brewer BH, Remaley AT, McGarrity GJ, Garcia-Blanco MA, Puttaraju M. Trans-splicing into highly abundant albumin transcripts for production of therapeutic proteins in vivo. Mol Ther 2009; 17:343-51. [PMID: 19066600 PMCID: PMC2835072 DOI: 10.1038/mt.2008.260] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Spliceosome-mediated RNA trans-splicing has emerged as an exciting mode of RNA therapy. Here we describe a novel trans-splicing strategy, which targets highly abundant pre-mRNAs, to produce therapeutic proteins in vivo. First, we used a pre-trans-splicing molecule (PTM) that mediated trans-splicing of human apolipoprotein A-I (hapoA-I) into the highly abundant mouse albumin exon 1. Hydrodynamic tail vein injection of the hapoA-I PTM plasmid in mice followed by analysis of the chimeric transcripts and protein, confirmed accurate and efficient trans-splicing into albumin pre-mRNA and production of hapoA-I protein. The versatility of this approach was demonstrated by producing functional human papillomavirus type-16 E7 (HPV16-E7) single-chain antibody in C57BL/6 mice and functional factor VIII (FVIII) and phenotypic correction in hemophilia A mice. Altogether, these studies demonstrate that trans-splicing to highly abundant albumin transcripts can be used as a general platform to produce therapeutic proteins in vivo.
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Affiliation(s)
- Jun Wang
- VIRxSYS Corporation, Gaithersburg, Maryland, USA
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83
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Hwang B, Lim JH, Hahm B, Jang SK, Lee SW. hnRNP L is required for the translation mediated by HCV IRES. Biochem Biophys Res Commun 2008; 378:584-8. [PMID: 19061868 DOI: 10.1016/j.bbrc.2008.11.091] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2008] [Accepted: 11/18/2008] [Indexed: 01/04/2023]
Abstract
Translation of hepatitis C virus (HCV) RNA is initiated by internal loading of the ribosome into the HCV internal ribosome entry site (IRES). Previously, heterogeneous ribonucleoprotein L (hnRNP L) was shown to bind specifically to the 3' border region of the HCV IRES and enhance HCV mRNA translation. Here, we provide evidence for the functional requirement of hnRNP L for the HCV IRES-mediated translation initiation using specific RNA aptamers. In vitro selection techniques were employed to isolate RNA aptamers against hnRNP L, which were shown to contain consensus sequences with repetitive ACAC/U. The hnRNP L-specific RNA aptamers efficiently inhibited the in vitro translation reactions mediated by the HCV IRES in rabbit reticulocyte lysates. RNA ligands with only (ACAU)5 or (AC)10 nucleotide sequences could also specifically bind to hnRNP L, and specifically and effectively impeded in vitro translation reactions controlled by the HCV IRES. Importantly, the hnRNP L-specific RNA aptamers inhibited the HCV IRES function in cells in a dose-dependent manner, and the aptamer-mediated inhibition of the HCV IRES was considerably relieved by the addition of hnRNP L-expressing vector. These results strongly demonstrate the functional requirement of cellular hnRNP L for the HCV IRES activity.
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Affiliation(s)
- Byounghoon Hwang
- Department of Molecular Biology, Institute of Nanosensor and Biotechnology, Dankook University, 126, Jukjeon-dong, Suji-gu, Yongin 448-701, Republic of Korea
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84
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Alemán EA, Lamichhane R, Rueda D. Exploring RNA folding one molecule at a time. Curr Opin Chem Biol 2008; 12:647-54. [DOI: 10.1016/j.cbpa.2008.09.010] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Revised: 08/29/2008] [Accepted: 09/12/2008] [Indexed: 01/21/2023]
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85
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Li YL, Vergne J, Torchet C, Maurel MC. In vitro selection of adenine-dependent ribozyme against Tpl2/Cot oncogene. FEBS J 2008; 276:303-14. [PMID: 19054068 DOI: 10.1111/j.1742-4658.2008.06780.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Hairpin ribozymes possess the properties of RNA sequence-specific recognition and site-specific cleavage. These properties make them a powerful extension of the antisense approach for the inhibition of gene expression. From a randomized RNA pool of hairpin ribozymes, using the systematic evolution of ligands by exponential enrichment, we have obtained an adenine-dependent hairpin ribozyme, Tpl2/Cot (tumour progression locus 2) ribozyme, which cleaves the Tpl2/Cot kinase mRNA sequence at nucleotides A225/G226 relative to the start codon of translation. This serine/threonine kinase activates the mitogen-activated protein kinase pathway implicated in cell proliferation in cancer. The selected 'Tpl2/Cot-YL ribozyme' efficiently cleaves its target sequence in cis and in trans; furthermore, the ribozyme efficiently cleaves a longer target sequence of 54 nucleotides in trans, as well as the full-length mRNA.
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Affiliation(s)
- Yan-Li Li
- Institut Jacques-Monod, Laboratoire de Biochimie de l'Evolution et Adaptabilité Moléculaire, UPMC Université Paris 06, Paris, France
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86
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So MK, Gowrishankar G, Hasegawa S, Chung JK, Rao J. Imaging Target mRNA and siRNA-Mediated Gene Silencing In Vivo with Ribozyme-Based Reporters. Chembiochem 2008; 9:2682-91. [DOI: 10.1002/cbic.200800370] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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87
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Demidov VV. Playing hard balls with RNA: fully automated ab initio RNA folding by discrete molecular dynamics. Drug Discov Today 2008. [DOI: 10.1016/j.drudis.2008.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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88
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Choi WH, Choi BR, Kim JH, Yeo WS, Oh S, Kim DE. Design and kinetic analysis of hammerhead ribozyme and DNAzyme that specifically cleave TEL-AML1 chimeric mRNA. Biochem Biophys Res Commun 2008; 374:169-74. [PMID: 18627769 DOI: 10.1016/j.bbrc.2008.07.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Accepted: 07/05/2008] [Indexed: 10/21/2022]
Abstract
In order to develop the oligonucleotides to abolish an expression of TEL-AML1 chimeric RNA, which is a genetic aberration that causes the acute lymphoblastic leukemia (ALL), hammerhead ribozymes and deoxyoligoribozymes that can specifically cleave TEL-AML1 fusion RNA were designed. Constructs of the deoxyribozyme with an asymmetric substrate binding arm (Dz26) and the hammerhead ribozyme with a 4nt-bulged substrate binding arm in the stem III (buRz28) were able to cleave TEL-AML1 chimeric RNA specifically at sites close to the junction in vitro, without cleaving the normal TEL and AML1 RNA. Single-turnover kinetic analysis under enzyme-excess condition revealed that the buRz28 is superior to the Dz26 in terms of substrate binding and RNA-cleavage. In conjunction with current progress in a gene-delivery technology, the designed oligonucleotides that specifically cleave the TEL-AML1 chimeric mRNA are hoped to be applicable for the treatment of ALL in vivo.
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Affiliation(s)
- Woo-Hyung Choi
- Department of Bioscience and Biotechnology, Konkuk University, 1-Hwayang-dong, Gwangjin-gu, Seoul 143-701, Republic of Korea
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89
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Wagner W, Wehrmann M. Differential cytokine activity and morphology during wound healing in the neonatal and adult rat skin. J Cell Mol Med 2008; 11:1342-51. [PMID: 18205704 PMCID: PMC4401296 DOI: 10.1111/j.1582-4934.2007.00037.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Wound-healing mechanisms change during transition from prenatal to postnatal stage. Cytokines are known to play a key role in this process. The current study investigated the differential cytokine activity and healing morphology during healing of incisional skin wounds in rats of the ages neonatal (p0), 3 days old (p3) and adult, after six different healing times (2 hrs to 30 days). All seven tested cytokines (Transforming Growth Factor (TGF) α, TGFβ1, −β2 and −β3, IGF 1, Platelet Derived Growth Factor A (PDGF A), basic Fibroblast Growth Factor (bFGF) exhibited higher expression in the adult wounds than at the ages p0 and p3. Expression typically peaked between 12 hrs and 3 days post-wounding, and was not detectable any more at days 10 and 30. The neonate specimen showed more rapid re-epithelialization, far less inflammation and scarring, and larger restitution of original tissue architecture than their adult counterparts, resembling a prenatal healing pattern. The results may encourage the use of neonatal rat skin as a wound-healing model for further studies, instead of the more complicated prenatal animal models. Secondly, the data may recommend inhibition of PDGF A, basic FGF or TGF-β1 as therapeutic targets in efforts to optimize wound healing in the adult organism.
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Affiliation(s)
- W Wagner
- Department of Otorhinolaryngology, University of Tübingen, Tübingen, Germany.
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90
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Jackson AM, Mulcahy LA, Zhu XW, O'Donnell D, Patel PM. Tumour-mediated disruption of dendritic cell function: Inhibiting the MEK1/2-p44/42 axis restores IL-12 production and Th1-generation. Int J Cancer 2008; 123:623-32. [DOI: 10.1002/ijc.23530] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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91
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Dendritic cell vaccines in melanoma: From promise to proof? Crit Rev Oncol Hematol 2008; 66:118-34. [DOI: 10.1016/j.critrevonc.2007.12.007] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Revised: 12/03/2007] [Accepted: 12/13/2007] [Indexed: 02/02/2023] Open
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92
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RNA interference in mammalia cells by RNA-3'-PNA chimeras. Int J Mol Sci 2008; 9:299-315. [PMID: 19325750 PMCID: PMC2635679 DOI: 10.3390/ijms9030299] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Revised: 02/29/2008] [Accepted: 02/29/2008] [Indexed: 12/12/2022] Open
Abstract
The discovery of siRNAs as the mediators of RNA interference has led to an increasing interest in their therapeutic applications. Chemical modifications are introduced into siRNAs to optimize the potency, the stability and the pharmacokinetic properties in vivo. Here, we synthesize and test the effects of RNA-3’-PNA chimeras on siRNA functioning and stability. We demonstrate that the chemical modifications are compatible with the siRNA machinery, because all the PNA-modified siRNAs can efficiently mediate specific gene silencing in mammalian cells. Furthermore, we find that the modification on the sense strand of siRNA results in an increased persistence of the activity, whereas modification on both strands results in enhanced nuclease resistance in serum.
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93
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Vicens Q, Allen MA, Gilbert SD, Reznik B, Gooding AR, Batey RT. The Cech Symposium: a celebration of 25 years of ribozymes, 10 years of TERT, and 60 years of Tom. RNA (NEW YORK, N.Y.) 2008; 14:397-403. [PMID: 18203922 PMCID: PMC2248266 DOI: 10.1261/rna.910008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The Cech Symposium was held in Boulder, Colorado, on July 12-13, 2007, to celebrate a triple anniversary: 25 years since the first publication reporting RNA self-splicing, 10 years since the identification of reverse transcriptase motifs in the catalytic subunit of telomerase, and 60 years since the birth of Thomas R. Cech. Past and present members of the Cech laboratory presented on their current research, which branched into many categories of study including RNA-mediated catalysis, telomerase and telomeres, new frontiers in nucleic acids, alternative splicing, as well as scientific research with direct medical applications.
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Affiliation(s)
- Quentin Vicens
- Howard Hughes Medical Institute, University of Colorado, Boulder, CO 80309-0215, USA.
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94
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Abstract
The ability of RNA to catalyze chemical reactions was first demonstrated 25 years ago with the discovery that group I introns and RNase P function as RNA enzymes (ribozymes). Several additional ribozymes were subsequently identified, most notably the ribosome, followed by intense mechanistic studies. More recently, the introduction of single molecule tools has dissected the kinetic steps of several ribozymes in unprecedented detail and has revealed surprising heterogeneity not evident from ensemble approaches. Still, many fundamental questions of how RNA enzymes work at the molecular level remain unanswered. This review surveys the current status of our understanding of RNA catalysis at the single molecule level and discusses the existing challenges and opportunities in developing suitable assays.
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Affiliation(s)
- Mark A Ditzler
- Biophysics Research Division, Single Molecule Analysis Group, University of Michigan, Ann Arbor, MI 48109, USA
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95
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Inhibition of in vivo tumor angiogenesis and growth via systemic delivery of an angiopoietin 2-specific RNA aptamer. J Surg Res 2007; 146:16-23. [PMID: 17950331 DOI: 10.1016/j.jss.2007.04.028] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2007] [Revised: 04/16/2007] [Accepted: 04/20/2007] [Indexed: 11/21/2022]
Abstract
BACKGROUND Cellular events mediated by the Tie2 receptor are important to tumor neovascularization. Despite the complex interplay of the best-characterized Tie2 ligands, angiopoietins 1 and 2, Ang2 is purportedly "proangiogenic" in the presence of vascular endothelial growth factor. We examined whether in vivo administration of an RNA aptamer that specifically blocks Ang 2 would inhibit tumor angiogenesis and growth. METHODS Ang2-mediated Tie2 receptor phosphorylation was assessed in vitro in the absence and presence of aptamer coupled to polyethylene glycol. IN VIVO ANGIOGENESIS ASSAY: CT26 murine colon carcinoma cells expressing green fluorescent protein were delivered into mouse dorsal skinfold window chambers. Animals received daily intraperitoneal injections of phosphate-buffered saline, low-dose (Ang2 aptamer-LD; 1 mg/kg/d), or high-dose aptamer (Ang2 aptamer-HD; 10 mg/kg/d). Vascular length density was measured under fluorescence microscopy. PRIMARY TUMOR GROWTH: CT26 cells expressing luciferase were injected into flanks of BALB/c mice to allow tumor growth monitoring by bioluminescence imaging. Animals received continuous phosphate-buffered saline or aptamer (1 mg/kg/d) via ALZET pumps. Tumors were assessed for CD31/PECAM-1 immunostaining and Hoechst dye uptake. RESULTS Pegylated aptamer inhibited Tie2 phosphorylation. Systemic aptamer administration reduced vascular length density (P < or = 0.03) and decreased bioluminescence emission (P < 0.04), corresponding to 50% decrease in tumor volume (P = 0.04). Control tumors displayed abundant vascular marker staining, in contrast to tumors from aptamer-treated animals. CONCLUSIONS in vivo administration of a clinically relevant, pegylated RNA aptamer specifically designed against Ang2 inhibited tumor angiogenesis and growth. These findings support targeted Ang2 inhibition as a relevant anti-angiogenic, anti-neoplastic strategy.
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96
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Famulok M, Hartig JS, Mayer G. Functional aptamers and aptazymes in biotechnology, diagnostics, and therapy. Chem Rev 2007; 107:3715-43. [PMID: 17715981 DOI: 10.1021/cr0306743] [Citation(s) in RCA: 666] [Impact Index Per Article: 39.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Michael Famulok
- LIMES Institute, Program Unit Chemical Biology and Medicinal Chemistry, c/o Kekulé-Institut für Organische Chemie und Biochemie, Gerhard Domagk-Strasse 1, 53121 Bonn, Germany.
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97
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Klausner EA, Peer D, Chapman RL, Multack RF, Andurkar SV. Corneal gene therapy. J Control Release 2007; 124:107-33. [PMID: 17707107 DOI: 10.1016/j.jconrel.2007.05.041] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2007] [Accepted: 05/15/2007] [Indexed: 12/23/2022]
Abstract
Gene therapy to the cornea can potentially correct inherited and acquired diseases of the cornea. Factors that facilitate corneal gene delivery are the accessibility and transparency of the cornea, its stability ex vivo and the immune privilege of the eye. Initial corneal gene delivery studies characterized the relationship between intraocular modes of administration and location of reporter gene expression. The challenge of achieving effective topical gene transfer, presumably due to tear flow, blinking and low penetration of the vector through epithlelial tight junctions left no alternative but invasive administration to the anterior chamber and corneal stroma. DNA vaccination, RNA interference and gene transfer of cytokines, growth factors and enzymes modulated the corneal microenvironment. Positive results were obtained in preclinical studies for prevention and treatment of corneal graft rejection, neovascularization, haze and herpetic stromal keratitis. These studies, corneal gene delivery systems and modes of administration, and considerations regarding the choice of animal species used are the focus of this review. Opportunities in the field of corneal gene therapy lie in expanding the array of corneal diseases investigated and in the implementation of recent designs of safer vectors with reduced immunogenicity and longer duration of gene expression.
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Affiliation(s)
- Eytan A Klausner
- Midwestern University Chicago College of Pharmacy, 555 31st Street, Downers Grove, IL 60515, United States.
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98
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Kim DW, Seo SW, Cho SK, Chang SS, Lee HW, Lee SE, Block JA, Hei TK, Lee FY. Targeting of cell survival genes using small interfering RNAs (siRNAs) enhances radiosensitivity of Grade II chondrosarcoma cells. J Orthop Res 2007; 25:820-8. [PMID: 17343283 DOI: 10.1002/jor.20377] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The main treatment for chondrosarcoma is surgical resection with a wide margin. However, there are certain chondrosarcomas, such as those found in the pelvis and the spine, which cannot be resected adequately with surgery alone. Unfortunately, most chondrosarcomas are resistant to radiation and chemotherapy. Radiation and chemotherapy are thought to kill chondrosarcoma cells by inducing apoptosis, or programmed cell death. In this article, we hypothesize that antiapoptotic gene silencing enhances radiosensitivity in chondrosarcoma cells by facilitating apoptotic pathways. We knocked down antiapoptotic genes in chondrosarcoma cells using small interfering RNAs (siRNAs). Two well-established Grade II human chondrosarcoma cell lines were pretreated with siRNAs that specifically target mRNAs for Bcl-2, Bcl-xL, or XIAP. The cells were then treated with radiation. Cell death was assessed by flow cytometry. Cell survival and proliferation were measured by clonogenic survival assays. Chondrosarcoma cells exhibited radioresistance and increased the expression of Bcl-2, Bcl-xL, and XIAP in response to radiation. When one of the Bcl-2, Bcl-xL, or XIAP genes was silenced with the corresponding siRNA, radiosensitivity increased up to 9.2-fold (p < 0.05). When two out of the three antiapoptotic mRNAs were knocked down simultaneously, there was an 11.3-fold increase in cell death after radiation (p < 0.05). Our findings support a novel therapeutic concept that gene silencing may be used as a molecular adjuvant therapy for radioresistant sarcomas.
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Affiliation(s)
- Dae Won Kim
- Department of Orthopaedic Surgery, Center for Orthopaedic Research, Columbia University, 630 West 168th Street BB14-1412, New York, NY 10032, USA
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99
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König J, Julius C, Baumann S, Homann M, Göringer HU, Feldbrügge M. Combining SELEX and the yeast three-hybrid system for in vivo selection and classification of RNA aptamers. RNA (NEW YORK, N.Y.) 2007; 13:614-22. [PMID: 17283213 PMCID: PMC1831868 DOI: 10.1261/rna.334307] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Aptamers are small nucleic acid ligands that bind to their targets with specificity and high affinity. They are generated by a combinatorial technology, known as SELEX. This in vitro approach uses iterative cycles of enrichment and amplification to select binders from nucleic acid libraries of high complexity. Here we combine SELEX with the yeast three-hybrid system in order to select for RNA aptamers with in vivo binding activity. As a target molecule, we chose the RNA recognition motif-containing RNA-binding protein Rrm4 from the corn pathogen Ustilago maydis. Rrm4 is an ELAV-like protein containing three N-terminal RNA recognition motifs (RRMs). It has been implicated in microtubule-dependent RNA transport during pathogenic development. After 11 SELEX cycles, four aptamer classes were identified. These sequences were further screened for their in vivo binding activity applying the yeast three-hybrid system. Of the initial aptamer classes only members of two classes were capable of binding in vivo. Testing representatives of both classes against Rrm4 variants mutated in one of the three RRM domains revealed that these aptamers interacted with the third RRM. Thus, the yeast three-hybrid system is a useful extension to the SELEX protocol for the identification and characterization of aptamers with in vivo binding activity.
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Affiliation(s)
- Julian König
- Department of Organismic Interactions, Max-Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse, Marburg, Germany
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100
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Abstract
It was only approximately 15 years ago that methodologies evolved to the point where we began to manipulate the genetic apparatus of the mouse such that proteins of the investigator's choice could be expressed in a 4-chambered, mammalian heart. Our abilities to express both normal and mutated proteins in the heart or to create genetic nulls in which the protein is not expressed at all continue to evolve. With the tools now available, one can target protein expression to the different cell types present in the heart, often at a particular time, and, in some cases, turn off the protein as development progresses or the animal ages. These abilities have enabled us to model many of the genetic mutations identified as causative for pediatric and/or adult cardiovascular disease and heart failure. Identifying the primary genetic cause is, more often than not, insufficient for designing effective therapeutics or interventions. Therefore, it is critical to be able to develop animal models that accurately recapitulate the pathogenic processes that ensue as a result of mutant gene expression or loss of protein expression. In this review, we discuss the nature, strengths, and weaknesses of the current set of tools for developing genetically manipulated mouse models, as well as the relevance of these models for understanding cardiovascular disease and illuminating potential therapeutic avenues.
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Affiliation(s)
- Katherine E Yutzey
- Division of Molecular Cardiovascular Biology, Department of Pediatrics, Children's Hospital Research Foundation, Cincinnati, OH 45229-3039, USA
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