A highly sensitive assay system for examining chemical mutagenesity and carcinogenesity using DNA repair-deficient mice

点击翻译按钮获取中文摘要

In order to establish a highly sensitive assay system for examining chemical mutagenesity and tumorigenesity, we performed KBrO_3-induced mutagenesis and tumorigenesis experiments using Ogg1-, Mutyh- or Msh2-deficient mice. We observed an enhanced tumor-formation in the small intestines of Mutyh- or Msh2-deficient mice, as compared with wild type and heterozygous mice. These results indicate that Mutyh- or Msh2-deficient mice are ideal animal models for examining tumorigenesity of chemicals of interest. The number of tumors was marginally increased in Ogg1-deficient mice in which the increased KBrO_3-induced mutagenesis was observed at an almost same extent as in Mutyh-deficient mice, suggesting that the induction of cell death might play a more important role than the suppression of mutagenesis for avoiding intestinal tumorigenesis caused by oxidative stress.