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Fujimoto K, Yoshinaga H, Yoshio Y, Sakamoto T. Quick and reversible photocrosslinking reaction of 3-cyanovinylcarbazole nucleoside in a DNA triplex. Org Biomol Chem 2013; 11:5065-8. [DOI: 10.1039/c3ob40915e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Mukherjee A, Vasquez KM. Triplex technology in studies of DNA damage, DNA repair, and mutagenesis. Biochimie 2011; 93:1197-208. [PMID: 21501652 DOI: 10.1016/j.biochi.2011.04.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Accepted: 04/01/2011] [Indexed: 12/18/2022]
Abstract
Triplex-forming oligonucleotides (TFOs) can bind to the major groove of homopurine-homopyrimidine stretches of double-stranded DNA in a sequence-specific manner through Hoogsteen hydrogen bonding to form DNA triplexes. TFOs by themselves or conjugated to reactive molecules can be used to direct sequence-specific DNA damage, which in turn results in the induction of several DNA metabolic activities. Triplex technology is highly utilized as a tool to study gene regulation, molecular mechanisms of DNA repair, recombination, and mutagenesis. In addition, TFO targeting of specific genes has been exploited in the development of therapeutic strategies to modulate DNA structure and function. In this review, we discuss advances made in studies of DNA damage, DNA repair, recombination, and mutagenesis by using triplex technology to target specific DNA sequences.
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Affiliation(s)
- Anirban Mukherjee
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Pediatric Research Institute, 1400 Barbara Jordan Blvd., Austin, TX 78723, USA
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Kolevzon N, Yavin E. Site-Specific DNA Photocleavage and Photomodulation by Oligonucleotide Conjugates. Oligonucleotides 2010; 20:263-75. [DOI: 10.1089/oli.2010.0247] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Netanel Kolevzon
- The School of Pharmacy, The Institute for Drug Research, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Eylon Yavin
- The School of Pharmacy, The Institute for Drug Research, The Hebrew University of Jerusalem, Jerusalem, Israel
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Vasquez KM. Targeting and processing of site-specific DNA interstrand crosslinks. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2010; 51:527-39. [PMID: 20196133 PMCID: PMC2895014 DOI: 10.1002/em.20557] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
DNA interstrand crosslinks (ICLs) are among the most cytotoxic types of DNA damage, and thus ICL-inducing agents such as cyclophosphamide, melphalan, cisplatin, psoralen, and mitomycin C have been used clinically as anticancer drugs for decades. ICLs can also be formed endogenously as a consequence of cellular metabolic processes. ICL-inducing agents continue to be among the most effective chemotherapeutic treatments for many cancers; however, treatment with these agents can lead to secondary malignancies, in part due to mutagenic processing of the DNA lesions. The mechanisms of ICL repair have been characterized more thoroughly in bacteria and yeast than in mammalian cells. Thus, a better understanding of the molecular mechanisms of ICL processing offers the potential to improve the efficacy of these drugs in cancer therapy. In mammalian cells, it is thought that ICLs are repaired by the coordination of proteins from several pathways, including nucleotide excision repair (NER), base excision repair (BER), mismatch repair (MMR), homologous recombination (HR), translesion synthesis (TLS), and proteins involved in Fanconi anemia (FA). In this review, we focus on the potential functions of NER, MMR, and HR proteins in the repair of and response to ICLs in human cells and in mice. We will also discuss a unique approach, using psoralen covalently linked to triplex-forming oligonucleotides to direct ICLs to specific sites in the mammalian genome.
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Affiliation(s)
- Karen M Vasquez
- Department of Carcinogenesis, The University of Texas M.D. Anderson Cancer Center, Science Park-Research Division, Smithville, Texas 78957, USA.
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Benfield AP, Macleod MC, Liu Y, Wu Q, Wensel TG, Vasquez KM. Targeted generation of DNA strand breaks using pyrene-conjugated triplex-forming oligonucleotides. Biochemistry 2008; 47:6279-88. [PMID: 18473480 DOI: 10.1021/bi7024029] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Gene targeting by triplex-forming oligonucleotides (TFOs) has proven useful for gene modulation in vivo. Photoreactive molecules have been conjugated to TFOs to direct sequence-specific damage in double-stranded DNA. However, the photoproducts are often repaired efficiently in cells. This limitation has led to the search for sequence-specific photoreactive reagents that can produce more genotoxic lesions. Here we demonstrate that photoactivated pyrene-conjugated TFOs (pyr-TFOs) induce DNA strand breaks near the pyrene moiety with remarkably high efficiency and also produce covalent pyrene-DNA adducts. Free radical scavenging experiments demonstrated a role for singlet oxygen activated by the singlet excited state of pyrene in the mechanism of pyr-TFO-induced DNA damage. In cultured mammalian cells, the effect of photoactivated pyr-TFO-directed DNA damage was to induce mutations, in the form of deletions, approximately 7-fold over background levels, at the targeted site. Thus, pyr-TFOs represent a potentially powerful new tool for directing DNA strand breaks to specific chromosomal locations for biotechnological and potential clinical applications.
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Affiliation(s)
- Aaron P Benfield
- Department of Carcinogenesis, The University of Texas M. D. Anderson Cancer Center, Science Park-Research Division, Smithville, Texas 78957, USA
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Oh DH, Hanawalt PC. Binding and Photoreactivity of Psoralen Linked to Triple Helix-Forming Oligonucleotides ¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2000)0720298bapopl2.0.co2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Ibrahim NM. The Behavior of Certain Coumarins and Furocoumarins Toward Sulfur Reagents. PHOSPHORUS SULFUR 2007. [DOI: 10.1080/10426500500536523] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Nabila M. Ibrahim
- a Department of Organometallic and Organometalloid Chemistry , National Research Centre , Dokki, Cairo, Egypt
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Gaddis SS, Wu Q, Thames HD, DiGiovanni J, Walborg EF, MacLeod MC, Vasquez KM. A web-based search engine for triplex-forming oligonucleotide target sequences. Oligonucleotides 2006; 16:196-201. [PMID: 16764543 DOI: 10.1089/oli.2006.16.196] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Triplex technology offers a useful approach for site-specific modification of gene structure and function both in vitro and in vivo. Triplex-forming oligonucleotides (TFOs) bind to their target sites in duplex DNA, thereby forming triple-helical DNA structures via Hoogsteen hydrogen bonding. TFO binding has been demonstrated to site-specifically inhibit gene expression, enhance homologous recombination, induce mutation, inhibit protein binding, and direct DNA damage, thus providing a tool for gene-specific manipulation of DNA. We have developed a flexible web-based search engine to find and annotate TFO target sequences within the human and mouse genomes. Descriptive information about each site, including sequence context and gene region (intron, exon, or promoter), is provided. The engine assists the user in finding highly specific TFO target sequences by eliminating or flagging known repeat sequences and flagging overlapping genes. A convenient way to check for the uniqueness of a potential TFO binding site is provided via NCBI BLAST. The search engine may be accessed at spi.mdanderson.org/tfo.
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Affiliation(s)
- Sara S Gaddis
- Department of Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Science Park-Research Division, Smithville, TX 78957, USA
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Richards S, Liu ST, Majumdar A, Liu JL, Nairn RS, Bernier M, Maher V, Seidman MM. Triplex targeted genomic crosslinks enter separable deletion and base substitution pathways. Nucleic Acids Res 2005; 33:5382-93. [PMID: 16186129 PMCID: PMC1236719 DOI: 10.1093/nar/gki851] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2005] [Revised: 09/03/2005] [Accepted: 09/03/2005] [Indexed: 12/02/2022] Open
Abstract
We have synthesized triple helix forming oligonucleotides (TFOs) that target a psoralen (pso) interstrand crosslink to a specific chromosomal site in mammalian cells. Mutagenesis of the targeted crosslinks results in base substitutions and deletions. Identification of the gene products involved in mutation formation is important for developing practical applications of pso-TFOs, and may be informative about the metabolism of other interstrand crosslinks. We have studied mutagenesis of a pso-TFO genomic crosslink in repair proficient and deficient cells. Deficiencies in non homologous end joining and mismatch repair do not influence mutation patterns. In contrast, the frequency of base substitutions is dependent on the activity of ERCC1/XPF and polymerase zeta, but independent of other nucleotide excision repair (NER) or transcription coupled repair (TCR) genes. In NER/TCR deficient cells the frequency of deletions rises, indicating that in wild-type cells NER/TCR functions divert pso-TFO crosslinks from processes that result in deletions. We conclude that targeted pso-TFO crosslinks can enter genetically distinct mutational routes that resolve to base substitutions or deletions.
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Affiliation(s)
- Sally Richards
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health5600 Nathan Shock Dr, Baltimore, MD 21224, USA
- University of Texas, MD Anderson Cancer Center, Department of CarcinogenesisPO Box 389, 1808 Park Road 1C, Smithville, TX 78957, USA
- Laboratory of Clinical Investigation, NIA/NIHBaltimore, MD 21224, USA
- Carcinogenesis Laboratory, Michigan State UniversityEast Lansing, MI 48824, USA
| | - Su-Ting Liu
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health5600 Nathan Shock Dr, Baltimore, MD 21224, USA
- University of Texas, MD Anderson Cancer Center, Department of CarcinogenesisPO Box 389, 1808 Park Road 1C, Smithville, TX 78957, USA
- Laboratory of Clinical Investigation, NIA/NIHBaltimore, MD 21224, USA
- Carcinogenesis Laboratory, Michigan State UniversityEast Lansing, MI 48824, USA
| | - Alokes Majumdar
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health5600 Nathan Shock Dr, Baltimore, MD 21224, USA
- University of Texas, MD Anderson Cancer Center, Department of CarcinogenesisPO Box 389, 1808 Park Road 1C, Smithville, TX 78957, USA
- Laboratory of Clinical Investigation, NIA/NIHBaltimore, MD 21224, USA
- Carcinogenesis Laboratory, Michigan State UniversityEast Lansing, MI 48824, USA
| | - Ji-Lan Liu
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health5600 Nathan Shock Dr, Baltimore, MD 21224, USA
- University of Texas, MD Anderson Cancer Center, Department of CarcinogenesisPO Box 389, 1808 Park Road 1C, Smithville, TX 78957, USA
- Laboratory of Clinical Investigation, NIA/NIHBaltimore, MD 21224, USA
- Carcinogenesis Laboratory, Michigan State UniversityEast Lansing, MI 48824, USA
| | - Rodney S. Nairn
- University of Texas, MD Anderson Cancer Center, Department of CarcinogenesisPO Box 389, 1808 Park Road 1C, Smithville, TX 78957, USA
| | - Michel Bernier
- Laboratory of Clinical Investigation, NIA/NIHBaltimore, MD 21224, USA
| | - Veronica Maher
- Carcinogenesis Laboratory, Michigan State UniversityEast Lansing, MI 48824, USA
| | - Michael M. Seidman
- To whom correspondence should be addressed. Tel: +1 410 558 8565; Fax: +1 410 558 8157;
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Wu Q, Christensen LA, Legerski RJ, Vasquez KM. Mismatch repair participates in error-free processing of DNA interstrand crosslinks in human cells. EMBO Rep 2005; 6:551-7. [PMID: 15891767 PMCID: PMC1369090 DOI: 10.1038/sj.embor.7400418] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2004] [Revised: 03/16/2005] [Accepted: 04/06/2005] [Indexed: 11/09/2022] Open
Abstract
DNA interstrand crosslinks (ICLs) present formidable blocks to DNA metabolic processes and must be repaired for cell survival. ICLs are induced in DNA by intercalating compounds such as the widely used therapeutic agent psoralen. In bacteria, both nucleotide excision repair (NER) and homologous recombination are required for the repair of ICLs. The processing of ICLs in mammalian cells is not clearly understood. However, it is known that processing can occur by NER, which for psoralen ICLs can be an error-generating process conducive to mutagenesis. We show here that another repair pathway, mismatch repair (MMR), is also involved in eliminating psoralen ICLs in human cells. MMR deficiency renders cells hypersensitive to psoralen ICLs without diminishing their mutagenic potential, suggesting that MMR does not contribute to error-generating repair, and that MMR may represent a relatively error-free mechanism for processing these lesions in human cells. Thus, enhancement of MMR relative to NER may reduce the mutagenesis caused by DNA ICLs in humans.
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Affiliation(s)
- Qi Wu
- Department of Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Science Park-Research Division, 1808 Park Road 1-C, Smithville, Texas 78957, USA
| | - Laura A. Christensen
- Department of Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Science Park-Research Division, 1808 Park Road 1-C, Smithville, Texas 78957, USA
| | - Randy J. Legerski
- Department of Molecular Genetics, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA
| | - Karen M. Vasquez
- Department of Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Science Park-Research Division, 1808 Park Road 1-C, Smithville, Texas 78957, USA
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Thoma BS, Wakasugi M, Christensen J, Reddy MC, Vasquez KM. Human XPC-hHR23B interacts with XPA-RPA in the recognition of triplex-directed psoralen DNA interstrand crosslinks. Nucleic Acids Res 2005; 33:2993-3001. [PMID: 15914671 PMCID: PMC1140082 DOI: 10.1093/nar/gki610] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
DNA interstrand crosslinks (ICLs) represent a severe form of damage that blocks DNA metabolic processes and can lead to cell death or carcinogenesis. The repair of DNA ICLs in mammals is not well characterized. We have reported previously that a key protein complex of nucleotide excision repair (NER), XPA-RPA, recognizes DNA ICLs. We now report the use of triplex technology to direct a site-specific psoralen ICL to a target DNA substrate to determine whether the human global genome NER damage recognition complex, XPC-hHR23B, recognizes this lesion. Our results demonstrate that XPC-hHR23B recognizes psoralen ICLs, which have a structure fundamentally different from other lesions that XPC-hHR23B is known to bind, with high affinity and specificity. XPC-hHR23B and XPA-RPA protein complexes were also observed to bind psoralen ICLs simultaneously, demonstrating not only that psoralen ICLs are recognized by XPC-hHR23B alone, but also that XPA-RPA may interact cooperatively with XPC-hHR23B on damaged DNA, forming a multimeric complex. Since XPC-hHR23B and XPA-RPA participate in the recognition and verification of DNA damage, these results support the hypothesis that interplay between components of the global genome repair sub-pathway of NER is critical for the recognition of psoralen DNA ICLs in the mammalian genome.
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Affiliation(s)
| | - Mitsuo Wakasugi
- Faculty of Pharmaceutical Sciences, Kanazawa UniversityTakara-machi, Kanazawa 920-0934, Japan
| | - Jesper Christensen
- Biotech Research and Innovation CentreFruebjergvej 3, 2100 Copenhagen, Denmark
| | | | - Karen M. Vasquez
- To whom correspondence should be addressed. Tel: +512 237 9324; Fax: +512 237 2475;
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Kundu M, Nagatsugi F, Majumdar A, Miller PS, Seidman MM. Enhancement and inhibition by 2'-O-hydroxyethyl residues of gene targeting mediated by triple helix forming oligonucleotides. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2004; 22:1927-38. [PMID: 14609232 DOI: 10.1081/ncn-120025240] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Reagents that recognize and bind specific genomic sequences in living mammalian cells would have great potential for genetic manipulation, including gene knockout, strain construction, and gene therapy. Triple helix forming oligonucleotides (TFOs) bind specific sequences via the major groove, but pyrimidine motif TFOs are limited by their poor activity under physiological conditions. Base and sugar analogues that overcome many of these limitations have been described. In particular, 2'-O-modifications influence sugar pucker and third strand conformation, and have been important to the development of bioactive TFOs. Here we have analyzed the impact of 2'-O-hydroxyethyl (2'-HE) substitutions, in combination with other 2' modifications. We prepared modified TFOs conjugated to psoralen and measured targeting activity in a gene knockout assay in cultured hamster cells. We find that 2'-HE residues enhance the bioactivity of TFOs containing 2'-O-methyl (2'-OMe) modifications, but reduce the bioactivity of TFOs containing, in addition, 2'-O-aminoethyl (2'-AE) residues.
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Affiliation(s)
- Mrinalkanti Kundu
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, USA
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Abstract
Psoralen-conjugated triplex-forming oligonucleotides (pso-TFOs) can target photochemical adducts to specific DNA sequences. Here, we have used pso-TFOs to activate gene expression on a plasmid. We designed a pso-TFO adapter, consisting of a single-stranded TFO for targeting DNA, linked to a double-stranded hairpin segment that contains a hybrid ecdysone response element (E/GRE) enhancer for binding activated ecdysone receptors. When targeted to the 5' flanking region of a minimal promoter, this pso-TFO adapter increased the expression of a downstream reporter gene three- to four-fold. Gene activation, however, was independent of both the E/GRE hairpin of the adapter and ecdysone receptors, suggesting it was due to an intrinsic effect of triplex. Gene activation was dependent on psoralen photo-crosslinking. Gene activation by pso-TFOs in which the psoralen was linked to the TFO via a disulfide bond was similar before and after detachment of the TFO and its release from the triplex. These results indicate that psoralen photo-crosslinks play a prominent role in activation. Gene activation was undiminished in XPA, XPD and XPG human cell lines, indicating that activation was not dependent on the complete nucleotide excision repair (NER) pathway. Collectively, these results demonstrate that TFOs can be used to direct psoralen crosslinks adjacent to a gene as a way of activating gene expression.
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Affiliation(s)
- Jie Song
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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Amosova O, Broitman SL, Fresco JR. Repairing the Sickle Cell mutation. II. Effect of psoralen linker length on specificity of formation and yield of third strand-directed photoproducts with the mutant target sequence. Nucleic Acids Res 2003; 31:4673-81. [PMID: 12907706 PMCID: PMC169896 DOI: 10.1093/nar/gkg659] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Three identical deoxyoligonucleotide third strands with a 3'-terminal psoralen moiety attached by linkers that differ in length (N = 16, 6 and 4 atoms) and structure were examined for their ability to form triplex-directed psoralen photoproducts with both the mutant T residue of the Sickle Cell beta-globin gene and the comparable wild-type sequence in linear duplex targets. Specificity and yield of UVA (365 nm) and visible (419 nm) light-induced photoadducts were studied. The total photoproduct yield varies with the linker and includes both monoadducts and crosslinks at various available pyrimidine sites. The specificity of photoadduct formation at the desired mutant T residue site was greatly improved by shortening the psoralen linker. In particular, using the N-4 linker, psoralen interaction with the residues of the non-coding duplex strand was essentially eliminated, while modification of the Sickle Cell mutant T residue was maximized. At the same time, the proportion of crosslink formation at the mutant T residue upon UV irradiation was much greater for the N-4 linker. The photoproducts formed with the wild-type target were fully consistent with its single base pair difference. The third strand with the N-4 linker was also shown to bind to a supercoiled plasmid containing the Sickle Cell mutation site, giving photoproduct yields comparable with those observed in the linear mutant target.
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Affiliation(s)
- Olga Amosova
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
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Intody Z, Perkins BD, Wilson JH, Wensel TG. Blocking transcription of the human rhodopsin gene by triplex-mediated DNA photocrosslinking. Nucleic Acids Res 2000; 28:4283-90. [PMID: 11058128 PMCID: PMC113126 DOI: 10.1093/nar/28.21.4283] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
To explore the ability of triplex-forming oligodeoxyribonucleotides (TFOs) to inhibit genes responsible for dominant genetic disorders, we used two TFOs to block expression of the human rhodopsin gene, which encodes a G protein-coupled receptor involved in the blinding disorder autosomal dominant retinitis pigmentosa. Psoralen-modified TFOs and UVA irradiation were used to form photoadducts at two target sites in a plasmid expressing a rhodopsin-EGFP fusion, which was then transfected into HT1080 cells. Each TFO reduced rhodopsin-GFP expression by 70-80%, whereas treatment with both reduced expression by 90%. Expression levels of control genes on either the same plasmid or one co-transfected were not affected by the treatment. Mutations at one TFO target eliminated its effect on transcription, without diminishing inhibition by the other TFO. Northern blots indicated that TFO-directed psoralen photoadducts blocked progression of RNA polymerase, resulting in truncated transcripts. Inhibition of gene expression was not relieved over a 72 h period, suggesting that TFO-induced psoralen lesions are not repaired on this time scale. Irradiation of cells after transfection with plasmid and psoralen-TFOs produced photoadducts inside the cells and also inhibited expression of rhodopsin-EGFP. We conclude that directing DNA damage with psoralen-TFOs is an efficient and specific means for blocking transcription from the human rhodopsin gene.
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Affiliation(s)
- Z Intody
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
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Oh DH, Hanawalt PC. Binding and Photoreactivity of Psoralen Linked to Triple Helix–Forming Oligonucleotides¶. Photochem Photobiol 2000. [DOI: 10.1562/0031-8655(2000)072<0298:bapopl>2.0.co;2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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