tRNA
            <sup>Val</sup>
            -heterodimeric maxizymes with high potential as geneinactivating agents: Simultaneous cleavage at two sites in HIV-1 tat mRNA in cultured cells

Kuwabara, Tomoko; Warashina, Masaki; Nakayama, Aya; Ohkawa, Jun; Taira, Kazunari

doi:10.1073/pnas.96.5.1886

Cited by 52 publications

(83 citation statements)

References 31 publications

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“…These results were not informative to know the further cellular function of Bradeion gene, and instead, we decided to disrupt Bradeion expression. With the advent of the development of hammerhead ribozymes and its derivatives reported by our institute, 10,11 the Bradeion mRNA containing a characteristic exonexon junction can be specifically targeted and cleaved without damaging a related Bradeion mRNA. Based on the results obtained using ras -inactivating ribozymes by Kijima et al, 7 Yamazaki et al, 8 and Tsuchida et al, 9 we succeeded in constructing and using Bradeion -and -specific ribozymes.…”

Section: Discussionmentioning

confidence: 99%

“…The ribozyme transcripts by this pol III -dependent expression system are much higher than that of pol II expression system. 10,11 The target sequences of these ribozymes and maxizymes in Bradeion mRNA are shown in Figure 1, A and B, and selected cleavage sites are indicated by black boxes.…”

Section: Design Of Trna Val -Driven Antisense Ribozymesmentioning

confidence: 99%

“…Therefore, we utilized the recently created ''maxizyme,'' which has an allosterically controllable function. 11 This allosteric form consists of two substrate binding arms and catalytic core region, and would have a cleavage activity only when the two substrate binding arms of the maxizyme interact with the Bradeion mRNA. In addition, pol IIIdependent expression system enables both ribozyme and maxizyme transcripts to be exported to the cytoplasm, which resulted in the presence of ribozymes and their target mRNA within the same cellular compartment.…”

Section: Design Of Trna Val -Driven Antisense Ribozymesmentioning

confidence: 99%

“…Stably transfected SW480 cells that harbored a ribozyme and /or maxizyme were selected by G418 (ribozyme and maxizyme ) and hygromycin (maxizyme ). 10,11 A total of 66 independent lines for each mutant ( Bradeion single mutant, Bradeion single mutant, and…”

Section: Growth Inhibition and Disruption Of Cell Division By The Clementioning

confidence: 99%

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Impaired expression of a human septin family gene Bradeion inhibits the growth and tumorigenesis of colorectal cancer in vitro and in vivo

et al. 2002

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We have identified a novel human septin family gene Bradeion, which is specifically expressed in human colorectal cancer and malignant melanoma. In order to analyze the implications of tumor -specific gene expression, ribozymes and its derivatives were specifically designed and transfected into various colorectal adenocarcinoma cell lines for Bradeion inactivation. We constructed ribozyme expression plasmids controlled by a human tRNA Val promoter, and both hammerhead ribozyme and its allosteric derivative maxizyme were used for two different forms of Bradeion mRNA. The sequence -specific cleavage of Bradeion mRNA resulted in significant growth inhibition and G2 arrest in human cancer cell lines, detected by flow cytometry analysis. In addition, in vivo mice studies demonstrated marked tumor growth suppression by the Bradeion -specific ribozymes. Thus, the tumor -specific and selective marker Bradeion also provides valuable tools as a potential target for colorectal cancer therapy.

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Section: Discussionmentioning

confidence: 99%

Section: Design Of Trna Val -Driven Antisense Ribozymesmentioning

confidence: 99%

Section: Design Of Trna Val -Driven Antisense Ribozymesmentioning

confidence: 99%

Section: Growth Inhibition and Disruption Of Cell Division By The Clementioning

confidence: 99%

See 2 more Smart Citations

Impaired expression of a human septin family gene Bradeion inhibits the growth and tumorigenesis of colorectal cancer in vitro and in vivo

et al. 2002

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“…The design can determine both the level of expression and the half-life of the expressed Rz (12). In previous studies we found that RNA polymerase III-mediated expression of Rz as tRNA fusions resulted in highly expressed stable [12][13][14].However, even these improved Rz were sometimes ineffective, probably because the Rz was unable to locate its target. One potential explanation for this ineffectiveness is that the ratelimiting step in vivo for the cleavage of phosphodiester bonds is the annealing͞association of the Rz with its target site (16).…”

mentioning

confidence: 99%

RNA–protein hybrid ribozymes that efficiently cleave any mRNA independently of the structure of the target RNA

Warashina

Kuwabara

Kato

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

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Ribozyme activity in vivo depends on achieving high-level expression, intracellular stability, target colocalization, and cleavage site access. At present, target site selection is problematic because of unforeseeable secondary and tertiary RNA structures that prevent cleavage. To overcome this design obstacle, we wished to engineer a ribozyme that could access any chosen site. To create this ribozyme, the constitutive transport element (CTE), an RNA motif that has the ability to interact with intracellular RNA helicases, was attached to our ribozymes so that the helicase-bound, hybrid ribozymes would be produced in cells. This modification significantly enhanced ribozyme activity in vivo, permitting cleavage of sites previously found to be inaccessible. To confer cleavage enhancement, the CTE must retain helicase-binding activity. Binding experiments demonstrated the likely involvement of RNA helicase(s). We found that attachment of the RNA motif to our tRNA ribozymes leads to cleavage in vivo at the chosen target site regardless of the local RNA secondary or tertiary structure. H ammerhead ribozymes (Rz) are small, naturally occurring catalytic RNAs that can be used as tools for basic research and show promise as therapeutic agents (1-3). Such RNAs can cleave oligoribonucleotides at specific sites (4) and have been used successfully to suppress gene expression in several different organisms (5-14). However, despite extensive efforts, the efficiency of Rz in vivo usually is not high enough to achieve the desired biological effect(s) (15). Successful gene inactivation by Rz in vivo depends strongly on the design of the expression vector. The design can determine both the level of expression and the half-life of the expressed Rz (12). In previous studies we found that RNA polymerase III-mediated expression of Rz as tRNA fusions resulted in highly expressed stable [12][13][14].However, even these improved Rz were sometimes ineffective, probably because the Rz was unable to locate its target. One potential explanation for this ineffectiveness is that the ratelimiting step in vivo for the cleavage of phosphodiester bonds is the annealing͞association of the Rz with its target site (16). In general, the regions that interact with DNA of DNA-cleaving restriction enzymes, such as EcoRI and EcoRV, are positively charged so that they can search for their target sites by sliding along the polynucleotide chain ( Fig. 1A; see refs. 17 and 18 for details of linear diffusion and the sliding mechanism). As a result, wherever such a restriction enzyme binds to DNA, it can locate the cleavage site efficiently by sliding along the DNA. Kinetically unfavorable and repetitive association͞dissociation events can be avoided during the search for the target site. Indeed, the cleavage efficiency of restriction enzymes increases with the length of the substrate DNA up to several thousand base pairs, a phenomenon that indicates that, once the restriction enzyme has bound to DNA, it can slide along the DNA strand for a few thousand base pa...

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‘Ethylene‐Bis[phosphonate] Nucleic Acids’: Novel Monomeric Synthons for the Solid‐Phase Synthesis of (PCH₂CH₂P)‐Bridged Oligonucleotides

Farschtschi¹

2004

Chemistry & Biodiversity

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An efficient synthesis of modified deoxyribonucleosidic building units, containing the 'ethylene-bisphosphonate nucleic acids' (EBPNAs) 1 or 2, has been developed. By means of solution-phase incorporation of 11, the oxidized form of 2, dinucleotide analogs of type 13 were prepared. The same strategy was used to incorporate 2 into the 5'-terminal position of the 12-mer homopolynucleotide methylphosphonate 14. A preliminary approach for solid-phase incorporation of the nucleosidic building block 1 into a preselected position of an oligonucleotide sequence to give 19 is presented, a reaction performed by means of a coupling strategy involving catalytic oxazaphospholidine-ring cleavage.

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tRNA ^Val -heterodimeric maxizymes with high potential as geneinactivating agents: Simultaneous cleavage at two sites in HIV-1 tat mRNA in cultured cells

Cited by 52 publications

References 31 publications

Impaired expression of a human septin family gene Bradeion inhibits the growth and tumorigenesis of colorectal cancer in vitro and in vivo

Impaired expression of a human septin family gene Bradeion inhibits the growth and tumorigenesis of colorectal cancer in vitro and in vivo

RNA–protein hybrid ribozymes that efficiently cleave any mRNA independently of the structure of the target RNA

‘Ethylene‐Bis[phosphonate] Nucleic Acids’: Novel Monomeric Synthons for the Solid‐Phase Synthesis of (PCH₂CH₂P)‐Bridged Oligonucleotides

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tRNA Val -heterodimeric maxizymes with high potential as geneinactivating agents: Simultaneous cleavage at two sites in HIV-1 tat mRNA in cultured cells

Cited by 52 publications

References 31 publications

Impaired expression of a human septin family gene Bradeion inhibits the growth and tumorigenesis of colorectal cancer in vitro and in vivo

Impaired expression of a human septin family gene Bradeion inhibits the growth and tumorigenesis of colorectal cancer in vitro and in vivo

RNA–protein hybrid ribozymes that efficiently cleave any mRNA independently of the structure of the target RNA

‘Ethylene‐Bis[phosphonate] Nucleic Acids’: Novel Monomeric Synthons for the Solid‐Phase Synthesis of (PCH2CH2P)‐Bridged Oligonucleotides

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tRNA ^Val -heterodimeric maxizymes with high potential as geneinactivating agents: Simultaneous cleavage at two sites in HIV-1 tat mRNA in cultured cells

‘Ethylene‐Bis[phosphonate] Nucleic Acids’: Novel Monomeric Synthons for the Solid‐Phase Synthesis of (PCH₂CH₂P)‐Bridged Oligonucleotides