核酸内切酶在DNA断裂损伤检测中的应用研究

Application of Endonuclease to Detecting the Strand Breaks of DNA Oxidative Damage

利用人体淋巴细胞和Hela细胞并经 10 0 μMH2 O2 诱导DNA损伤 ,然后分为对照组和实验组 ,后者补充 2 5 μl 1μg/ml的核酸内切酶Ⅲ。结果显示对照组淋巴细胞经 4h培养后DNA断裂损伤下降到 6 3 85 (专用单位 ) ;补充核酸内切酶Ⅲ的实验组DNA断裂损伤明显增加达到 16 1 93 (P <0 0 5 )。对照组Hela细胞培养 4h后DNA断裂损伤为 19,而实验组断裂损伤明显高于对照组达到 172 1(P <0 0 1)。提示实验组DNA断裂损伤的增高可能包括H2 O2 所致DNA直接断裂和核酸内切酶Ⅲ切除修复过程中所形成的修复性断裂两部分 ,反映了DNA总体损伤水平。

The damaged lymphocytes and Hela cells were divided into control groups and supplemental groups treated with 25μl of 1μl/ml endonuclease Ⅲ.The results showed that the damage of DNA strand breaks of lympnocytes was much lower in control with 63 85 arbitary units(AU) than supplement group about 161 93 after 4 hour culture(P<0 05).The similar result was found in Hela cells.The DNA strand breaks were significantly increased from 19 0 in control group to 172 1 in suppiement groups(P<0 01) after 4 hour culture.It was indicated that the supplementation of endonuclease Ⅲ played an important role in the base incision repair and produced a lot of strand breaks from enzymic incision for DNA repair.