Adams R L, Fulton J, Kirk D
Biochim Biophys Acta. 1982 Jun 30;697(3):286-94. doi: 10.1016/0167-4781(82)90091-4.
By growing cells in the presence of 3 mM thymidine and 5-azadeoxycytidine up to 20% of DNA cytosines have been substituted with azacytosine. No substitution was obtained on incubating with 5-methyldeoxycytidine. Azacytosine-substituted DNA has a very low level of 5-methylcytosine and cells, which survive azadeoxycytidine treatments maintain this low level of methylation in the absence of the drug. The DNA of such cells is undermethylated fairly evenly in all classes of DNA e.g., satellite and unique DNA. Incubation of cells in azadeoxycytidine leads to high cell mortality which is not related to the lack of DNA methylation but may be linked to the altered interactions of proteins with the substituted DNA. This effect, rather than reduced DNA methylation, may be the cause of differentiative changes observed on treatment of cells with 5-azacytidine.
通过在3 mM胸苷和5-氮杂脱氧胞苷存在的情况下培养细胞，高达20%的DNA胞嘧啶已被氮杂胞嘧啶取代。与5-甲基脱氧胞苷孵育未获得取代。氮杂胞嘧啶取代的DNA具有非常低水平的5-甲基胞嘧啶，并且在氮杂脱氧胞苷处理后存活的细胞在没有该药物的情况下保持这种低水平的甲基化。此类细胞的DNA在所有类型的DNA（例如卫星DNA和单一DNA）中甲基化程度均相当均匀地降低。在氮杂脱氧胞苷中孵育细胞会导致高细胞死亡率，这与DNA甲基化的缺乏无关，但可能与蛋白质与取代的DNA之间改变的相互作用有关。这种效应，而非DNA甲基化的降低，可能是在用5-氮杂胞苷处理细胞时观察到的分化变化的原因。
