101
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Li H, Fu X, Chen Y, Hong Y, Tan Y, Cao H, Wu M, Wang H. Use of adenovirus-delivered siRNA to target oncoprotein p28GANK in hepatocellular carcinoma. Gastroenterology 2005; 128:2029-41. [PMID: 15940635 DOI: 10.1053/j.gastro.2005.03.001] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND & AIMS RNA interference (RNAi) is a powerful tool to silence gene expression. The adenoviral vector expressing small interfering RNA (siRNA) is highly effective in mammalian cells. However, its potential use as a therapeutic tool to target an oncogene specifically remains to be seen. We applied the adenovirus-delivered siRNA (AdSiRNA) to inhibit a hepatocellular carcinoma (HCC) oncogene, p28GANK, in HCC cell lines and investigated its antitumor effects. METHODS The T7-RNA polymerase system was used to screen the specific target site. Double-strand oligonucleotide for transcription of short hairpin RNA was constructed into the adenoviral vector. Four HCC cell lines were infected with the RNAi-containing adenovirus. The RNAi effects on HCC were studied in cultured cells as well as in animal models. RESULTS p28GANK expression was suppressed by up to 80% in HCC cells. Depletion of p28GANK inhibited HCC cell growth and tumorigenesis, enhanced dephosphorylation of RB1, and decreased transcription activity of E2F-1 in HuH-7 cells. Furthermore, depletion of p28GANK induced caspase-8- and caspase-9-mediated apoptosis of HCC cells. Finally, targeting p28GANK by adenovirus injection inhibited the growth of established tumors in nude mice. CONCLUSIONS This study shows that the T7-system screening-based AdSiRNA can be used successfully to silence an oncogene. We proved the therapeutic potential of AdSiRNA on the treatment of HCC by targeting p28GANK. Our results indicate that p28GANK may serve as a novel therapeutic target for treating HCC.
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Affiliation(s)
- Honghai Li
- International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Shanghai, Peoples Republic of China
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102
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Dillon CP, Sandy P, Nencioni A, Kissler S, Rubinson DA, Van Parijs L. Rnai as an experimental and therapeutic tool to study and regulate physiological and disease processes. Annu Rev Physiol 2005; 67:147-73. [PMID: 15709955 DOI: 10.1146/annurev.physiol.67.040403.130716] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Over the past four years RNA interference (RNAi) has exploded onto the research scene as a new approach to manipulate gene expression in mammalian systems. More recently, RNAi has garnered much interest as a potential therapeutic strategy. In this review, we briefly summarize the current understanding of RNAi biology and examine how RNAi has been used to study the genetic basis of physiological and disease processes in mammalian systems. We also explore some of the new developments in the use of RNAi for disease therapy and highlight the key challenges that currently limit its application in the laboratory, as well as in the clinical setting.
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Affiliation(s)
- Christopher P Dillon
- Center for Cancer Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
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103
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Maeda Y, Fukushima K, Nishizaki K, Smith RJH. In vitro and in vivo suppression of GJB2 expression by RNA interference. Hum Mol Genet 2005; 14:1641-50. [PMID: 15857852 DOI: 10.1093/hmg/ddi172] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Mutations in GJB2 (gap junction protein, beta-2) are the major cause of autosomal recessive non-syndromic hearing loss. A few allele variants of this gene also cause autosomal dominant non-syndromic hearing loss as a dominant-negative consequence of expression of the mutant protein. Allele-specific gene suppression by RNA interference (RNAi) is a potentially attractive strategy to prevent hearing loss caused by this mechanism. In this proof-of-principle study, we identified a potent GJB2-targeting short interfering RNA (siRNA) to post-transcriptionally silence the expression of the R75W allele variant of GJB2 in cultured mammalian cells. In a mouse model, this siRNA duplex selectively suppressed GJB2(R75W) expression by >70% of control levels, thereby preventing hearing loss. The level of endogenous murine Gjb2 expression was not affected. Our data show that RNAi can be used with specificity and efficiency in vivo to protect against hearing loss caused as a dominant-negative consequence of mutant gene expression.
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Affiliation(s)
- Yukihide Maeda
- Molecular Otolaryngology Research Laboratory, Department of Otolaryngology-Head and Neck Surgery, Interdepartmental Ph.D. Genetics Program, The University of Iowa, 200 Hawkins Drive-21151 PFP, Iowa City, IA 52242, USA
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104
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Ill CR, Chiou HC. Gene Therapy Progress and Prospects: Recent progress in transgene and RNAi expression cassettes. Gene Ther 2005; 12:795-802. [PMID: 15815698 DOI: 10.1038/sj.gt.3302524] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Plasmid expression cassette design must include a thoughtful analysis of potentially every nucleotide comprising a covalently closed circular or end-protected linear DNA. This review will discuss recent studies in unraveling the mechanisms of postdelivery gene silencing, codon optimization and promoter identification. The recent discovery of potent RNA interference (RNAi) mechanisms for sequence-specific gene silencing has also invoked a great deal of interest in development of expression cassettes that can produce double-stranded RNA molecules for RNAi. Expression cassettes based on both RNA polymerase II and polymerase III transcription units that generate double-stranded RNA molecules for RNAi will also be discussed.
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Affiliation(s)
- C R Ill
- Research Division, CancerVax Corporation, Carlsbad, CA 92008, USA
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105
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Vanhaesebroeck B, Ali K, Bilancio A, Geering B, Foukas LC. Signalling by PI3K isoforms: insights from gene-targeted mice. Trends Biochem Sci 2005; 30:194-204. [PMID: 15817396 DOI: 10.1016/j.tibs.2005.02.008] [Citation(s) in RCA: 357] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Phosphoinositide 3-kinases (PI3Ks) generate lipids that control a wide variety of intracellular signalling pathways. Part of this diversity in PI3K actions stems from the broad range of protein effectors of the PI3K lipids. A further layer of complexity is added by the existence of multiple isoforms of PI3K. Gene-targeting studies in the mouse have recently uncovered key roles for specific PI3K isoforms in immunity, metabolism and cardiac function. Remarkably, some of these actions do not require PI3K catalytic activity. In addition, loss-of-expression of certain PI3K genes leads to increased PI3K signalling following insulin stimulation. PI3K gene targeting has, in many cases, led to altered expression of the non-targeted PI3K subunits, making it difficult to exclude that some of the reported phenotypes result from 'knock-on' effects of PI3K gene deletion. Targeting strategies that take into account the complex interplay between members of the PI3K family will be crucial to gain a full understanding of the physiological roles of the isoforms of PI3K.
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Affiliation(s)
- Bart Vanhaesebroeck
- Ludwig Institute for Cancer Research, 91 Riding House Street, London W1W 7BS, UK.
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106
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Abstract
RNA interference (RNAi) is now an umbrella term referring to post-transcriptional gene silencing mediated by either degradation or translation arrest of target RNA. This process is initiated by double-stranded RNA with sequence homology driving specificity. The discovery that 21-23 nucleotide RNA duplexes (small-interfering RNAs, siRNAs) mediate RNAi in mammalian cells opened the door to the therapeutic use of siRNAs. While much work remains to optimize delivery and maintain specificity, the therapeutic advantages of siRNAs for treatment of viral infection, dominant disorders, cancer, and neurological disorders show great promise.
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Affiliation(s)
- R C C Ryther
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
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107
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Schwarzer R, Tondera D, Arnold W, Giese K, Klippel A, Kaufmann J. REDD1 integrates hypoxia-mediated survival signaling downstream of phosphatidylinositol 3-kinase. Oncogene 2005; 24:1138-49. [PMID: 15592522 DOI: 10.1038/sj.onc.1208236] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Cancer cells frequently evade apoptosis during tumorigenesis by acquiring mutations in apoptotic regulators. Chronic activation of the PI 3-kinase-Akt pathway through loss of the tumor suppressor PTEN is one mechanism by which these cells can gain increased protection against apoptosis. We report here that REDD1 (RTP801) can act as a transcriptional downstream target of PI 3-kinase signaling in human prostate cancer cells (PC-3). REDD1 expression is markedly reduced in PC-3 cells treated with LY294002 (LY) or Rapamycin and strongly induced under hypoxic conditions in a hypoxia-inducible factor-1 (HIF-1)-dependent manner. Loss of function studies employing antisense molecules or RNA interference indicate that REDD1 is essential for invasive growth of prostate cancer cells in vitro and in vivo. Reduced REDD1 levels can sensitize cells towards apoptosis, whereas elevated levels of REDD1 induced by hypoxia or overexpression desensitize cells to apoptotic stimuli. Taken together our data designate REDD1 as a novel target for therapeutic intervention in prostate cancer.
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Affiliation(s)
- Rolf Schwarzer
- Atugen AG, Otto Warburg Haus (Nr. 80), Robert-Roessle-Strasse 10, 13125 Berlin, Germany
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108
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Abstract
RNA interference (RNAi) is an efficient post-transcriptional gene silencing mechanism that is induced by double-stranded RNA. Applications of RNAi have gained increasing attention since the groundbreaking discovery that small interfering RNA (siRNA) molecules can be used to inhibit gene expression in mammalian cells in a sequence-specific manner. Numerous meetings have recently been held in this field, but the organiser from EF International succeeded in bringing some of the leading academic scientists and company researchers together in London to present and discuss exciting new results. Major topics covered in the meeting included the recent progress in understanding the basic mechanism of RNAi, genome-wide RNAi-based screens for target discovery, and approaches to use RNAi for target validation in cell culture and in animal models. In addition, borders and caveats of the technology, such as off-target effects and a possible induction of the interferon response by siRNA, have been discussed intensively. The use of siRNAs can be regarded as a highly potent strategy to identify and validate new targets for therapeutic interventions against cancer, viral infections, chronic pain and other diseases. Finally, siRNAs themselves hold the promise to become therapeutic agents in the near future.
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Affiliation(s)
- Jens Kurreck
- Institute for Chemistry (Biochemistry), Free University Berlin, Thielallee 63, 14195 Berlin, Germany.
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109
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Drees BE, Mills GB, Rommel C, Prestwich GD. Therapeutic potential of phosphoinositide 3-kinase inhibitors. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.14.5.703] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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110
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Taulli R, Accornero P, Follenzi A, Mangano T, Morotti A, Scuoppo C, Forni PE, Bersani F, Crepaldi T, Chiarle R, Naldini L, Ponzetto C. RNAi technology and lentiviral delivery as a powerful tool to suppress Tpr-Met-mediated tumorigenesis. Cancer Gene Ther 2005; 12:456-63. [PMID: 15719029 DOI: 10.1038/sj.cgt.7700815] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Tpr-Met, the oncogenic counterpart of the Met receptor, has been detected in gastric cancers, as well as in precursor lesions and in the adjacent normal gastric mucosa. This has prompted the suggestion that Tpr-Met may predispose to the development of gastric tumors. Given the sequence specificity of RNA interference, oncogenes activated by point mutation or rearrangements can be targeted while spearing the product of the wild-type allele. In this work, we report specific suppression of Tpr-Met expression and inhibition of Tpr-Met-mediated transformation and tumorigenesis by means of a short interfering RNA (siRNA) directed toward the Tpr-Met junction (anti-TM2). When delivered by a lentiviral vector, anti-TM2 siRNA was effective also in mouse embryonal fibroblasts or epithelial cells expressing high levels of Tpr-Met. Our results suggest that lentiviral-mediated delivery of anti-TM2 siRNA may be developed into a powerful tool to treat Tpr-Met-positive cancers.
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Affiliation(s)
- Riccardo Taulli
- Center for Experimental Research and Medical Studies (CERMS), Molinette Hospital, Turin, Italy
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111
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Lelievre E, Bourbon PM, Duan LJ, Nussbaum RL, Fong GH. Deficiency in the p110alpha subunit of PI3K results in diminished Tie2 expression and Tie2(-/-)-like vascular defects in mice. Blood 2005; 105:3935-8. [PMID: 15687236 PMCID: PMC1895075 DOI: 10.1182/blood-2004-10-3955] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phosphoinositide 3-kinase (PI3K) is activated by transmembrane tyrosine kinases such as vascular endothelial growth factor (VEGF) receptors and Tie2 (tunica intima endothelial kinase 2), both of which are key regulators of vascular development. However, the in vivo role of PI3K during developmental vascularization remains to be defined. Here we demonstrate that mice deficient in the p110alpha catalytic subunit of PI3K display multiple vascular defects, including dilated vessels in the head, reduced branching morphogenesis in the endocardium, lack of hierarchical order of large and small branches in the yolk sac, and impaired development of anterior cardinal veins. These vascular defects are strikingly similar to those in mice defective in the Tie2 signaling pathway. Indeed, Tie2 protein levels were significantly lower in p110alpha-deficient mice. Furthermore, RNA interference of p110alpha in cultured endothelial cells significantly reduced Tie2 protein levels. These findings raise the possibility that PI3K may function as an upstream regulator of Tie2 expression during mouse development.
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MESH Headings
- Animals
- Cells, Cultured
- Embryo, Mammalian/abnormalities
- Embryo, Mammalian/blood supply
- Embryo, Mammalian/embryology
- Embryo, Mammalian/metabolism
- Endothelial Cells/metabolism
- Gene Expression Regulation, Developmental
- Mice
- Mice, Knockout
- Phosphatidylinositol 3-Kinases/deficiency
- Phosphatidylinositol 3-Kinases/genetics
- Phosphatidylinositol 3-Kinases/metabolism
- Protein Subunits/deficiency
- Protein Subunits/genetics
- Protein Subunits/metabolism
- Receptor, TIE-2/deficiency
- Receptor, TIE-2/genetics
- Receptor, TIE-2/metabolism
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Affiliation(s)
- Etienne Lelievre
- Center for Vascular Biology, University of Connecticut Health Center, 263 Farmington Ave, Farmington, CT 06030-3501, USA
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112
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Abstract
Inhibition of growth and progression of cancer cells is a challenge with major potential impact. RNA interference (RNAi) technology has been rapidly developed as a laboratory tool for the downregulation of the expression of a gene of interest. Moreover, RNAi offers a new potential for gene therapy of particular neoplasms by the specific inhibition of a cancer-associated target. This article will briefly describe the mechanism and application possibilities of RNAi, and illustrate the therapeutic potential in cancer gene therapy. The utilization of RNAi technology as a potential therapeutic tool for the treatment of cancer will be discussed in detail for two specific targets; the Bcr-Abl tyrosine kinase and the multidrug transporter MDR1/P-glycoprotein.
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Affiliation(s)
- Hermann Lage
- Charité Campus Mitte, Institute of Pathology, For-schumannstr. 20/21 D-10117 Berlin, Germany
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113
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Lin X, Yang J, Chen J, Gunasekera A, Fesik SW, Shen Y. Development of a tightly regulated U6 promoter for shRNA expression. FEBS Lett 2005; 577:376-80. [PMID: 15556613 DOI: 10.1016/j.febslet.2004.10.033] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2004] [Revised: 10/12/2004] [Accepted: 10/13/2004] [Indexed: 11/29/2022]
Abstract
Short hairpin RNAs (shRNAs) have been used to achieve stable target knockdown in a variety of biological systems. Here, we report the development of a tightly regulated tetracycline-responsive human U6 promoter for shRNA expression. By engineering two copies of the tet operators flanking the TATA box of the human U6 promoter, we created a U6 promoter derivative (2O2) that exhibited much lower basal transcriptional activity compared with recently reported inducible pol III dependent promoters. As a consequence of its tighter regulation, the 2O2 system greatly improved the success rate in making inducible knockdown cell lines.
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MESH Headings
- Blotting, Western
- Cell Line, Tumor
- Cloning, Molecular
- Gene Expression Regulation/drug effects
- Genes, Reporter
- Genetic Variation
- HeLa Cells
- Humans
- Luciferases/metabolism
- Molecular Sequence Data
- Promoter Regions, Genetic
- RNA, Small Interfering/chemistry
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- Sequence Homology, Nucleic Acid
- TATA Box
- Tetracycline/pharmacology
- Transcription, Genetic
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Affiliation(s)
- Xiaoyu Lin
- Cancer Research, Global Pharmaceutical Research and Development, AP10/L01, Abbott Laboratories, 100 Abbott Park Road, Abbott Park, IL 60064, USA
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114
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Yu JY, Wang TW, Vojtek AB, Parent JM, Turner DL. Use of short hairpin RNA expression vectors to study mammalian neural development. Methods Enzymol 2005; 392:186-99. [PMID: 15644182 DOI: 10.1016/s0076-6879(04)92011-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The use of RNA interference (RNAi) in mammalian cells has become a powerful tool for the analysis of gene function. Here we discuss the use of DNA vectors to produce short hairpin RNAs (shRNAs) and inhibit gene expression in mammalian neural progenitors and neurons. Protocols are presented for introducing shRNA vectors into mouse P19 cells differentiated as neurons in vitro and for electroporation of shRNA vectors into primary neural progenitors from the embryonic mouse dorsal telencephalon (prospective cerebral cortex). Transfected primary cortical progenitors can be differentiated in vitro either in dissociated culture or organotypic slice culture. The use of shRNA vectors for RNAi provides a versatile approach to understand gene function during mammalian neural development.
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Affiliation(s)
- Jenn-Yah Yu
- Program in Neuroscience, University of Michigan, Ann Arbor, MI 48109-0669, USA
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115
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Sano M, Kato Y, Akashi H, Miyagishi M, Taira K. Novel Methods for Expressing RNA Interference in Human Cells. Methods Enzymol 2005; 392:97-112. [PMID: 15644177 DOI: 10.1016/s0076-6879(04)92006-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
RNA interference (RNAi) is a conserved process in which a double-stranded RNA (dsRNA) induces sequence-specific gene silencing. Recent developments in the use of the 21-nt small interfering RNA (siRNA) have allowed the specific degradation of mRNA without induction of nonspecific effects in mammalian cells. RNAi provides a method for knocking down genes of interest and a powerful tool for studies on gene functions in various organisms. Although many vector-based siRNA expression systems have been developed for production of siRNAs in mammalian cells, many technical issues for an effective production of siRNAs still need to be resolved. In this chapter, we describe methods for construction of genetically stable and highly active siRNA expression systems and also mention some strategies to overcome serious technical problems.
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Affiliation(s)
- Masayuki Sano
- Gene Function Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba Science City, Japan
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116
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Mogass M, York TP, Li L, Rujirabanjerd S, Shiang R. Genomewide analysis of gene expression associated with Tcof1 in mouse neuroblastoma. Biochem Biophys Res Commun 2004; 325:124-32. [PMID: 15522210 DOI: 10.1016/j.bbrc.2004.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2004] [Indexed: 11/28/2022]
Abstract
Mutations in the Treacher Collins syndrome gene, TCOF1, cause a disorder of craniofacial development. We manipulated the levels of Tcof1 and its protein treacle in a murine neuroblastoma cell line to identify downstream changes in gene expression using a microarray platform. We identified a set of genes that have similar expression with Tcof1 as well as a set of genes that are negatively correlated with Tcof1 expression. We also showed that the level of Tcof1 and treacle expression is downregulated during differentiation of neuroblastoma cells into neuronal cells. Inhibition of Tcof1 expression by siRNA induced morphological changes in neuroblastoma cells that mimic differentiation. Thus, expression of Tcof1 and treacle synthesis play an important role in the proliferation of neuroblastoma cells and we have identified genes that may be important in this pathway.
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Affiliation(s)
- Michael Mogass
- Department of Human Genetics, Virginia Commonwealth University Medical Center, P.O. Box 980033, Richmond, VA 23298-0033, USA
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117
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Malphettes L, Fussenegger M. Macrolide- and tetracycline-adjustable siRNA-mediated gene silencing in mammalian cells using polymerase II-dependent promoter derivatives. Biotechnol Bioeng 2004; 88:417-25. [PMID: 15382105 DOI: 10.1002/bit.20230] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
RNA interference has emerged as a powerful technology for downregulation of specific genes in cells and animals. We have pioneered macrolide- and tetracycline-adjustable short interfering RNA (siRNA) expression for conditional target gene translation fine-tuning in mammalian/human cell lines based on modified RNA polymerase II promoters. Established macrolide- and tetracycline-dependent transactivators/trans-silencers bound and activated modified target promoters tailored for optimal siRNA expression in response to clinical antibiotics' dosing regimes and modulated desired target genes in Chinese hamster ovary (CHO-K1) and human fibrosarcoma (HT-1080) cells with high precision. Further optimization of adjustable RNA polymerase II-based siRNA-specific promoters as well as their combination with various transmodulators enabled near-perfect regulation configurations in specific cell types. Devoid of major genetic constraints compared to basic RNA polymerase III-based siRNA-specific promoters, we expect RNA polymerase II counterparts to significantly advance siRNA-based molecular interventions in biopharmaceutical manufacturing and gene-function analysis as well as gene therapy and tissue engineering.
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Affiliation(s)
- Laetitia Malphettes
- Institute of Biotechnology, Swiss Federal Institute of Technology, ETH Hönggerberg, HPT D74, CH-8093 Zurich, Switzerland
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118
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Downward J. Use of RNA interference libraries to investigate oncogenic signalling in mammalian cells. Oncogene 2004; 23:8376-83. [PMID: 15517019 DOI: 10.1038/sj.onc.1208073] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Over the past decade, 'RNA interference' has emerged as a natural mechanism of silencing of gene expression. This ancient cellular antiviral response can be manipulated to provide an effective research tool to knock down the level of expression of selected target genes, providing a very powerful new method for the analysis of cell signalling pathways. Systematic silencing of genes on a genome-wide scale using large rationally designed libraries targeting many thousands of genes provides a novel functional genomics approach to the investigation of many aspects of mammalian cell behaviour, including oncogenic transformation. Here, the different approaches taken to use RNA interference libraries to study the cancer phenotype will be considered, including both selective and high throughput screens and the use of both vector-based and synthetic oligonucleotide-based methods for inducing RNA interference. The advantages and drawbacks of the competing methodologies will be discussed. RNA interference library technology holds great promise for enabling somatic cell genetics in tissue culture systems. Whether it can provide significant new insights into cancer will be its greatest challenge.
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Affiliation(s)
- Julian Downward
- Cancer Research UK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3PX, UK.
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119
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Wadhwa R, Kaul SC, Miyagishi M, Taira K. Know-how of RNA interference and its applications in research and therapy. Mutat Res 2004; 567:71-84. [PMID: 15341903 DOI: 10.1016/j.mrrev.2004.06.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2004] [Revised: 06/18/2004] [Accepted: 06/18/2004] [Indexed: 12/11/2022]
Abstract
Double stranded RNA (dsRNA) mediates gene silencing in a sequence specific manner. Originally recognized in plants and lower organisms, it was recently extended to higher eukaryotes and established as an important evolutionary conserved phenomenon. It has been established that the double stranded short interfering RNAs (siRNAs) originate by the activity of a dsRNA-specific endonuclease, Dicer. siRNA in conjunction with a multiple enzyme complex called RNA-induced silencing complex (RISC) locates to the specific sites on mRNA and degrades it by endonuclease and exonuclease activities. In addition to gene silencing at transcript level (degradation of messenger RNA), siRNA was also shown to reduce the expression of protein by silencing of gene promoters via de novo methylation. By virtue of their specific gene silencing activity and owing to the recent discoveries on their plasmid and virus driven expression, small dsRNAs are being widely adopted in research and therapeutics. They are rapidly replacing the conventional gene knock-out technologies. siRNA libraries are also being recruited as a new tool in genome wide functional screenings. There is no doubt that further progress in understanding the mechanism of their action as well as strategies to achieve their tightly regulated and tissue specific expression will revolutionize basic and applied biomedical research.
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Affiliation(s)
- Renu Wadhwa
- Gene Function Research Center, National Institute of Advanced Industrial, Science and Technology, 1-1-1 Higashi, Tsukuba 305-8562, Japan
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120
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Leenders F, Möpert K, Schmiedeknecht A, Santel A, Czauderna F, Aleku M, Penschuck S, Dames S, Sternberger M, Röhl T, Wellmann A, Arnold W, Giese K, Kaufmann J, Klippel A. PKN3 is required for malignant prostate cell growth downstream of activated PI 3-kinase. EMBO J 2004; 23:3303-13. [PMID: 15282551 PMCID: PMC514518 DOI: 10.1038/sj.emboj.7600345] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2004] [Accepted: 07/05/2004] [Indexed: 12/23/2022] Open
Abstract
Chronic activation of the phosphoinositide 3-kinase (PI3K)/PTEN signal transduction pathway contributes to metastatic cell growth, but up to now effectors mediating this response are poorly defined. By simulating chronic activation of PI3K signaling experimentally, combined with three-dimensional (3D) culture conditions and gene expression profiling, we aimed to identify novel effectors that contribute to malignant cell growth. Using this approach we identified and validated PKN3, a barely characterized protein kinase C-related molecule, as a novel effector mediating malignant cell growth downstream of activated PI3K. PKN3 is required for invasive prostate cell growth as assessed by 3D cell culture assays and in an orthotopic mouse tumor model by inducible expression of short hairpin RNA (shRNA). We demonstrate that PKN3 is regulated by PI3K at both the expression level and the catalytic activity level. Therefore, PKN3 might represent a preferred target for therapeutic intervention in cancers that lack tumor suppressor PTEN function or depend on chronic activation of PI3K.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Axel Wellmann
- Pathologisches Institut der Unikliniken, Bonn, Germany
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Ichim TE, Li M, Qian H, Popov IA, Rycerz K, Zheng X, White D, Zhong R, Min W. RNA interference: a potent tool for gene-specific therapeutics. Am J Transplant 2004; 4:1227-36. [PMID: 15268723 PMCID: PMC7175948 DOI: 10.1111/j.1600-6143.2004.00530.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
RNA interference (RNAi) is a process through which double-stranded RNA induces the activation of cellular pathways, leading to potent and selective silencing of genes with homology to the double strand. Much excitement surrounding small interfering RNA (siRNA)-mediated therapeutics arises from the fact that this approach overcomes many of the shortcomings previously experienced with approaches such as antibodies, antisense oligonucleotides and pharmacological inhibitors. Induction of RNAi through administration of siRNA has been successfully used in treatment of hepatitis, viral infections, and cancer. In this review we will present a brief history of RNAi, methods of inducing RNAi, application of RNAi in the therapeutic setting, and the possibilities of using this highly promising approach in the context of transplantation.
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Affiliation(s)
- Thomas E. Ichim
- Department of Surgery, Microbiology and Immunology, University of Western Ontario
- Multi‐Organ Transplant program, London Health Sciences Centre
| | - Mu Li
- Department of Surgery, Microbiology and Immunology, University of Western Ontario
- Multi‐Organ Transplant program, London Health Sciences Centre
| | - Hua Qian
- Department of Surgery, Microbiology and Immunology, University of Western Ontario
- Multi‐Organ Transplant program, London Health Sciences Centre
| | - Igor A. Popov
- Department of Surgery, Microbiology and Immunology, University of Western Ontario
- Multi‐Organ Transplant program, London Health Sciences Centre
| | - Katarzyna Rycerz
- Department of Surgery, Microbiology and Immunology, University of Western Ontario
| | - Xiufen Zheng
- Department of Surgery, Microbiology and Immunology, University of Western Ontario
| | - David White
- Department of Surgery, Microbiology and Immunology, University of Western Ontario
- Multi‐Organ Transplant program, London Health Sciences Centre
- Immunology and Transplantation, Lawson Health Research Institute, and
- Robarts Research Institute, London, ON, Canada
| | - Robert Zhong
- Department of Surgery, Microbiology and Immunology, University of Western Ontario
- Multi‐Organ Transplant program, London Health Sciences Centre
- Immunology and Transplantation, Lawson Health Research Institute, and
- Robarts Research Institute, London, ON, Canada
| | - Wei‐Ping Min
- Department of Surgery, Microbiology and Immunology, University of Western Ontario
- Multi‐Organ Transplant program, London Health Sciences Centre
- Immunology and Transplantation, Lawson Health Research Institute, and
- Robarts Research Institute, London, ON, Canada
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Tondera D, Santel A, Schwarzer R, Dames S, Giese K, Klippel A, Kaufmann J. Knockdown of MTP18, a Novel Phosphatidylinositol 3-Kinase-dependent Protein, Affects Mitochondrial Morphology and Induces Apoptosis. J Biol Chem 2004; 279:31544-55. [PMID: 15155745 DOI: 10.1074/jbc.m404704200] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We identified a novel human cDNA encoding a mitochondrial protein, MTP18 (mitochondrial protein, 18 kDa) as a transcriptional downstream target of phosphatidylinositol (PI) 3-kinase signaling. We demonstrate that MTP18 mRNA as well as protein expression is dependent on PI 3-kinase activity. Confocal microscopy and biochemical fractionation revealed a mitochondrial localization of MTP18. Loss-of-function analysis employing antisense molecules revealed that MTP18 is essential for cell viability in PC-3 and HaCaT cells. We show that knockdown of MTP18 protein level results in a cytochrome c release from mitochondria and consequently leads to apoptosis. In addition, HaCaT cells with reduced levels of MTP18 become more sensitive to apoptotic stimuli. This effect is accompanied by dramatic subcellular alterations. Reduction of MTP18 impairs mitochondrial morphology resulting in the formation of a highly interconnected mitochondrial reticulum in COS-7 cells. Conversely, overexpression of MTP18 induces a punctuate morphology of mitochondria suggesting also a functional role of MTP18 in maintaining the mitochondrial integrity. Hence, our data indicate an unexpected connection of PI 3-kinase signaling, apoptosis and the morphology of mammalian mitochondria.
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Affiliation(s)
- Daniel Tondera
- Atugen AG, Otto Warburg Haus (Nr. 80), Robert-Rössle-Strasse 10, 13125 Berlin, Germany
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Affiliation(s)
- Vivek Mittal
- Cancer Genome Research Center, Cold Spring Harbor Laboratory, 500 Sunnyside Boulevard, Woodbury, New York 11797, USA.
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Dorsett Y, Tuschl T. siRNAs: applications in functional genomics and potential as therapeutics. Nat Rev Drug Discov 2004; 3:318-29. [PMID: 15060527 DOI: 10.1038/nrd1345] [Citation(s) in RCA: 653] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Yair Dorsett
- Laboratory of RNA Molecular Biology, Rockefeller University, 1230 York Avenue, Box 186, New York, New York 10021, USA
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125
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Higuchi M, Tsutsumi R, Higashi H, Hatakeyama M. Conditional gene silencing utilizing the lac repressor reveals a role of SHP-2 in cagA-positive Helicobacter pylori pathogenicity. Cancer Sci 2004; 95:442-7. [PMID: 15132773 PMCID: PMC11160029 DOI: 10.1111/j.1349-7006.2004.tb03229.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2004] [Revised: 02/27/2004] [Accepted: 03/11/2004] [Indexed: 12/11/2022] Open
Abstract
RNA interference (RNAi) is a newly described biological phenomenon mediated by small interfering RNA (siRNA) that targets mRNA for degradation by cellular enzymes and has become a powerful method for studying gene functions in mammalian systems. The development of systems for inducing siRNA expression should enable examination of acute loss-of-function phenotypes in a cell of interest without the need to consider lethality or epigenetic adaptation of cells. We describe in this report an inducible siRNA expression system made by combined utilization of the RNA polymerase III-dependent promoter H1 and the bacterial lac repressor. Using this system, we established AGS gastric epithelial cells in which expression of SHP-2, a cellular tyrosine phosphatase known to specifically bind the Helicobacter pylori virulence factor CagA, is conditionally and reversibly silenced by the lactose analog isopropyl-1-thio-beta-D-galactopyranoside (IPTG). Upon expression in AGS cells, CagA provoked a morphological transformation, termed the hummingbird phenotype, which is associated with CagA virulence. This morphogenetic activity of CagA was totally abolished when SHP-2 expression was silenced by inducible siRNA expression in AGS cells. Our results indicate that SHP-2 is a critical downstream effector of H. pylori CagA. The conditional gene silencing system described here should become a powerful tool for investigating the roles of cancer-related genes through a reversed genetic approach.
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Affiliation(s)
- Megumi Higuchi
- Division of Molecular Oncology, Institute for Genetic Medicine, Hokkaido University, Kita-ku, Sapporo 060-0815, Japan
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Kasim V, Miyagishi M, Taira K. Control of siRNA expression using the Cre-loxP recombination system. Nucleic Acids Res 2004; 32:e66. [PMID: 15107481 PMCID: PMC407841 DOI: 10.1093/nar/gnh061] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Gene silencing mediated by RNA interference (RNAi) was first discovered in Caenorhabditis elegans, and was subsequently recognized in various other organisms. In mammalian cells, RNAi can be induced by small interfering RNAs (siRNAs). In earlier studies, our group developed a vector-based system for expression of siRNA under control of a polymerase III promoter, the U6 promoter, which can induce RNAi in living cells. We here describe a system for controlling the U6 promoter-driven expression of siRNA using the Cre-loxP recombination system. We constructed a 'Cre-On' siRNA expression vector which could be switched on upon excision catalyzed by Cre recombinase, which was delivered to cells directly from the medium as a fusion protein. An examination of the effectiveness of RNAi against a reporter gene revealed that addition of TAT-NLS-Cre (where NLS is a nuclear localization signal and TAT is a peptide of 11 amino acids derived from HIV) to the medium resulted in plasmid recombination, generation of siRNA and suppression of reporter activity. This system should allow us to induce RNAi in a spatially, temporally, cell type-specifically or tissue-specifically controlled manner and potentiate the improved application of RNAi in both an experimental and a therapeutic context.
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Affiliation(s)
- Vivi Kasim
- Department of Chemistry and Biotechnology, School of Engineering, University of Tokyo, Hongo, Tokyo 113-8656, Japan
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Abstract
A relatively recent entrant into molecular biology--double-stranded RNA (dsRNA)--as a class exhibits a unique set of properties: relative stability, affinity for specific proteins and enzymes, ability to activate the interferon pathway and finally, RNA interference (RNAi). In RNAi, unique double-stranded short interfering RNA molecules (siRNA) destroy the corresponding target RNA with exquisite potency and selectivity, thus causing post-transcriptional gene silencing (PTGS). An understanding of the design of gene-specific dsRNA and development of techniques to deliver dsRNA in the cell and in live animals has heralded a new age of gene therapy without gene knockout. This review first summarizes the biological synthesis, metabolism and effect of the dsRNA with special emphasis on siRNA and RNAi. This is followed by the clinical, pharmacological and pharmaceutical prospects of the development of the dsRNA as a drug. It is clear that the dsRNA holds an enormous promise in the treatment of a large number of metabolic and infectious diseases including but not limited to cancer, macular degeneration, diabetic retinopathy, Alzheimer's and other neural disorders, autoimmune diseases, and all viral infections including AIDS (acquired immune deficiency syndrome), hepatitis and respiratory syncytial virus (RSV).
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Affiliation(s)
- Sailen Barik
- Department of Biochemistry and Molecular Biology, University of Southern Alabama, College of Medicine, Mobile 36688-0002, USA.
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Affiliation(s)
- Andrew Dodd
- Molecular Genetics and Development Group, School of Biological Sciences, University of Auckland, Auckland 1001, New Zealand
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