1999 Fiscal Year Final Research Report Summary
Development of highly functional medicines targeting genomic DNA/RNA
| Project/Area Number |
09557201
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
医薬分子機能学
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| Research Institution | Osaka University |
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Principal Investigator |
IMANISHI Takeshi Graduate School of Pharmaceutical Sciences, Osaka University, Professor, 薬学研究科, 教授 (40028866)
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| Co-Investigator(Kenkyū-buntansha) |
OBIKA Satoshi Graduate School of Pharmaceutical Sciences, Osaka University, Research Associate, 薬学研究科, 助手 (80243252)
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| Project Period (FY) |
1997 – 1999
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| Keywords | Nucleoside Analog / Oligonucleotide / Antisense / Conformation / Cationic Liposome / Gene Delivery |
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| Research Abstract |
In order to develop novel and highly functional medicines which can inhibit a target gene expression selectively, we designed and synthesized nucleoside analogues as a key synthon for an antisense or an antigene molecule. We accomplished the effective synthesis of the novel nucleoside analogues in which the sugar puckering was restricted in N-conformation. These nucleoside analogues were introduced into oligonucleotides by using a DNA synthesizer, giving conformationally locked oligonucleotides. The properties of these modified oligonucleotides as an antisense or an antigene molecule were studied by Tm measurements, gel retardation experiments, DNase I footprinting experiments. From these experiments, unprecedented thermal stabilities of duplex formation towards complementary DNA and RNA were observed. Furthermore, good triplex forming abilities of the modified oligonucleotides were also confirmed. In addition, the selective inhibition of the target gene expression in living cells was accomplished by addition of these modified oligonucleotides into cell culture medium. These results clearly indicate that the conformationally locked oligonucelotide was a promising candidate for an antisense and an antigene molecule.
On the other hands, development of an ideal gene delivery system is of great importance for antisense and antigene methodology and other gene therapies. Therefore, we designed and synthesized novel symmetrical cationic lipids which have biodegradable ester linkages. The cationic liposomes prepared from the cationic lipids and natural lipid DOPE show an efficient gene delivery into living cells and low cytotoxicity. It means that this cationic liposome is an effective gene delivery reagent.
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