Pfohl-Leszkowicz A, Dirheimer G
Cancer Res. 1986 Mar;46(3):1110-3.
The activity of de novo DNA (cytosine-5-)-methyltransferase (DNA methylase) in various rat tissues after administration of a single dose of N-methyl-N-nitrosourea (MNU) has been analyzed. The total and specific activities of the DNA methylase of the brain, where tumor induction is important, are increased. In kidney, the DNA methylase activity first increases up to 16 h and decreases afterwards. Liver DNA methylase activity does not change. This organ is not susceptible to MNU induced cancers. Because organs in which the DNA methylase activity is high or increased after MNU are more prone to carcinogenesis by this compound, we argue that there is a relationship between the effects of MNU and DNA methylase activity.
分析了单次给予N-甲基-N-亚硝基脲（MNU）后，不同大鼠组织中从头DNA（胞嘧啶-5-）-甲基转移酶（DNA甲基化酶）的活性。在对肿瘤诱导很重要的大脑中，DNA甲基化酶的总活性和比活性均增加。在肾脏中，DNA甲基化酶活性最初在16小时内升高，之后下降。肝脏DNA甲基化酶活性没有变化。该器官对MNU诱导的癌症不敏感。由于MNU后DNA甲基化酶活性高或增加的器官更容易被这种化合物致癌，我们认为MNU的作用与DNA甲基化酶活性之间存在关联。
