癌变·畸变·突变 ›› 2000, Vol. 12 ›› Issue (1): 31-033.doi: 10.3969/j.issn.1004-616x.2000.01.009

• 论著 • 上一篇    下一篇

补充核酸内切酶Ⅲ对DNA 氧化损伤影响的研究

杜 卫2 ,刘四朝2 ,马爱国1   

  1. 11 青岛大学医学院医学营养学系, 山东青岛 266021  21 中国农业科学院研究生院,北京
  • 收稿日期:1999-02-04 修回日期:1999-07-20 出版日期:2000-01-30 发布日期:2000-01-30

THE EFFECT OF ENDONUCLEASE ⅢSUPPLEMENTATION ON THE DAMAGE OF DNA STRAND BREAKS

DU Wei, LIU Si-chao, MA Ai-guo   

  1. The Department of Human Nutrition, Qingdao Medical College, Qingdao  266021, China
  • Received:1999-02-04 Revised:1999-07-20 Online:2000-01-30 Published:2000-01-30

摘要: 目的:核酸内切酶Ⅲ在DNA 损伤的切补修复体系中可能发挥着重要作用,是否有效地促进DNA 损伤修复本文进行了探讨。方法:本研究采用“彗星”电泳技术分析DNA 断裂损伤,利用人体淋巴细胞和Hela 细胞并用100μmolH2O2 诱导DNA 严重损伤,其损伤分别达到19815 和320 (专用单位,AU) ,然后再将两种细胞各分为两组;一组为对照组,另一组为实验组补充25μl (1μg/ ml) 的核酸内切酶Ⅲ. 在培养至30min ,60min ,180min 和240min 时观察DNA 断裂损伤情况。结果:淋巴细胞DNA断裂损伤在对照组中经过4h 培养后逐渐得到修复,DNA 损伤由初始时的19815 下降到64127 (AU) ;补充核酸内切酶Ⅲ的实验组尽管DNA 断裂经过4h 后也得到修复,但DNA 断裂损伤率仍明显高于对照组( P 均< 0. 05) 。Hela 细胞对H2O2 表现出较高的敏感性并有极强的自身修复能力,对照组DNA 断裂损伤从初始时的320 下降到4h 后的19 (AU) ,自身修复率达到9411 % ,然而补充核酸内切酶Ⅲ的Hela 细胞DNA 断裂损伤率在30min、60min、180min、240min 时均明显高于对照组( P < 0.05) 。结论:本结果提示核酸内切酶Ⅲ在DNA 损伤修复中增加了DNA 的断裂损伤率。

关键词: 核酸内切酶Ⅲ, 彗星电泳, DNA 损伤, DNA 修复

Abstract: Purpose and Methods : The aim of the study was observing the effect of endonuclease Ⅲsupplementation on the damage of DNA st rand breaks , which were measured by comet assay (SCGE) . Results : DNA stran break damage of lymphocytes and Hela cells induced by 100μmol H2O2 in cont rols reached 198. 5 and 320 arbitary units respectively. The rate of DNA st rand breaks of lymphocytes was gradually decreased f rom the beginning to 4 hour culture in cont rol group. At the end of 4 hour culture , there was a much lower rate of DNA repair in Endonuclease Ⅲgroup with 33. 4 % than cont rol group with 67. 6 % ( P < 0. 05) . The same result was found in HeLa cells. The levels of DNA st rand breaks was quickly decreased f rom 320 to 19 arbitary units in control group within 4 hour culture , whereas the DNA st rand breaks in supplementing group with Endonuclease Ⅲwas kept at a high level with 172. 0 arbitary unit s at 4 hour culture ( P < 0. 05) . Conclusion : The study suggested that the supplementation of endonuclease Ⅲcould increase the levels of DNA st rand breaks.

Key words: endonuclease Ⅲ, SCGE, lymphocyte, DNA repair, DNA damage

中图分类号: