FEN-1基因对细胞周期和遗传稳定性的影响  

The Influence of FEN-1 Gene on Cell Cycle and Genetic Stability

作　　者：石斌山[1] 余应年[1] 蔡朱男[1] 沈炳辉 

机构地区：[1]浙江大学医学院病理生理教研室,杭州310031 [2]City of Hope National Medical Center and Beckman Research Institute

出　　处：《生物化学与生物物理学报》2001年第3期309-314,共6页

基　　金：国家自然科学基金资助项目!(No .39830 2 10 ;No.39870 340 )&&

摘　　要：结构特异性核酸酶FEN 1在DNA复制和修复 ,以及维持细胞遗传稳定性方面都起着重要作用。采用RT PCR方法 ,证实了FEN 1基因阻断细胞 (FL FEN 1-)通过FEN 1反义mRNA片段的表达 ,阻断了FEN 1基因。应用流式细胞仪对FL FEN 1-细胞进行细胞周期分析 ,发现FL FEN 1-细胞进入S期DNA合成的过程被延缓 ,并发生了G1期的阻滞。在由穿梭质粒 pZ189介导的突变试验中 ,质粒在FL FEN 1-细胞中复制后 ,其SupFtRNA基因的自发突变频率为 19.1× 10 4 ,而对照细胞FL和FL M细胞分别为 2 .9× 10 4 和 3.0× 10 4 ,但FL FEN 1-细胞经甲基硝基亚硝基胍 (MNNG)诱发后的非定标突变频率与对照细胞并无明显差异 ,这表明由FEN 1阻断造成的突变频率升高与细胞在受低浓度MNNG攻击后发生的非定标突变可能通过不同的途径形成。FL FENFEN 1 is essential in the cell replication, repair and in the maintenance of cellular genetic stability. In this report, it was verfied that FEN 1 antisense mRNA fragment was expressed in the cell line FL FEN 1 -, constructed in our lab, blocking FEN 1 gene expression. It was found by the flow cytometer analysis that the cell cycle of FL FEN 1 - cells was delayed in the S phase DNA synthesis process and arrested in G 1 phase. In a mutation assay, based on the shuttle plasmid pZ189, the spontaneous mutation frequency of SupF tRNA gene in the plasmid in the FL FEN 1 - cells was 19.1×10 4, while it was 2.9×10 4 and 3.0×10 4 in the control cells FL and FL M, respectively. Further study showed that nontargeted mutation frequency of the FL FEN 1 - cell induced by MNNG was almost the same as the control, indicating that the mutants derived from the block of FEN 1 gene and the nontargeted mutants may be formed through different passways. The FL FEN 1 - cells exhibit increased sensitivity to alkylating agent MNNG.

关 键 词：FEN-1 细胞周期 遗传稳定性 非定标突变 MNNG敏感性 核酸酶 DNA修复 

分 类 号：Q25[生物学—细胞生物学]