1991 Fiscal Year Final Research Report Summary
The Studies on The Repair of DNA Damage Induced in Human Cells Irradiated with Ultraviolet Light (UV).
| Project/Area Number |
02454547
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
放射線5生物学
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| Research Institution | Kanazawa Univeristy. |
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Principal Investigator |
NIKAIDO Osamu. Kanazawa University, Faculty of Pharmaceutical Sciences, Professor., 薬学部, 教授 (60019669)
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| Co-Investigator(Kenkyū-buntansha) |
ISHIGAKI Yasuhito Kanazawa University, Faculty of Pharmaceutical Sciences, Research Associate., 薬学部, 教務職員 (20232275)
MATSUNAGA Tsukasa. Kanazawa University, Faculty of Pharmaceutical Sciences, Research Associate (199, 薬学部, 助手 (60192340)
SUZUKI Fumio. Knazawa University, Faculty of Pharmaceutical Sciences, Associate Professor., 薬学部, 助教授 (10019672)
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| Project Period (FY) |
1990 – 1991
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| Keywords | Thymine Dimer / (6-4) photoproducts / Dewar photoproducts / In vitro repair / Repair-patch size / Monoclonal antibody / Repair replication / Excision |
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| Research Abstract |
We established 9 monoclonal antibodies directed against ultraviolet (UV) light-induced DNA damage. Three of them recognize cyclobutane-type thymine dimers. Other 5 recognize (6-4) photoproducts, and one the Dewar isomer of (6-4) photoproducts.
By using these antibodies for assessing the amount of DNA damage induced and repaired in human cells irradiated with various wavelength of UV, we showed that human cells irradiated with 10 J/m^2 of 254 nm UV completely excised the (6-4) photoproducts from cellular DNA by 12 hr, whereas 50 % of thymine dimers remained in DNA 24 hr after UV-irradiation.
We incorporated in the present study ; an in vitro repair system using UV-irradiated plasmid and human cell-free extract. We found that the repair replication taken place in UV-plasmids was accompanied with the excision of both thymine dimers and (6-4) photoproducts. Furthermore, we investigated the repair of thymine dimers introduced in the plasmid by irradiating with 313 nm UV in the presence of acetophenone, and found that the repair-patch size of thymine dimer in the repair system settled from 14 to 24 bases per thymine dimer. This result resembles coincidentally to that of Eschericha coli.
The action spectra for the induction of photodamage in DNA irradiated with various wavelength of UV were analysed by the monoclonal antibodies. It was revealed that (6-4) photoproducts were efficiently photoisomerized by longer wavelength of UV (around 320 nm) which is contained in solar light. The results indicate that thymine dimers and the Dewar photoproducts are the main DNA damage induced by solar UV.
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