Graduate School of Biomedical and Health Sciences , Hiroshima University , 1-2-3 Kasumi , Minami-ku, Hiroshima 734-8553 , Japan.
Chem Res Toxicol. 2018 May 21;31(5):319-324. doi: 10.1021/acs.chemrestox.8b00009. Epub 2018 Apr 12.
O-Methylguanine ( O-MeG) is a damaged base produced by methylating reagents. The Werner syndrome protein (WRN) is a cancer-related human DNA helicase. The effects of WRN reduction on O-MeG-caused mutagenesis were assessed by an siRNA-mediated knockdown in human U2OS cells, using a shuttle plasmid with a single O-MeG base in the supF gene. The plasmid DNA was replicated in the cells, isolated, and electroporated into an Escherichia coli indicator strain. The lowered amount of WRN increased the frequency of mutations induced by O-MeG, mainly G:C → A:T substitution. The increased mutation rate suggested that the cancer-related WRN suppresses the G:C → A:T substitution by O-MeG in human cells.
O-甲基鸟嘌呤（O-MeG）是一种由甲基化试剂产生的受损碱基。 Werner 综合征蛋白（WRN）是一种与癌症相关的人类 DNA 解旋酶。通过在含有单个 O-MeG 碱基的 supF 基因中的穿梭质粒，利用 siRNA 介导的人 U2OS 细胞中的 WRN 敲低，评估了 WRN 减少对 O-MeG 引起的诱变的影响。质粒 DNA 在细胞中复制，分离，并电穿孔到大肠杆菌指示菌株中。WRN 的含量降低增加了 O-MeG 诱导的突变频率，主要是 G:C→A:T 取代。增加的突变率表明，与癌症相关的 WRN 通过 O-MeG 抑制了人细胞中的 G:C→A:T 取代。
