Bouck N, Kokkinakis D, Ostrowsky J
Mol Cell Biol. 1984 Jul;4(7):1231-7. doi: 10.1128/mcb.4.7.1231-1237.1984.
The permanent cell line BHK-21/cl 13 can be transformed by mutagenic carcinogens as the result of the induction of a recessive somatic mutation. Yet when these cells were treated with 5-azacytidine under conditions in which no mutants resistant to either ouabain or 6-thioguanine could be detected, they were transformed efficiently. These transformants were induced, not selected. 6-Azacytidine was ineffective at transforming BHK cells; 2'-deoxy-5-azacytidine was exceptionally effective. When tested by cell fusion, transformants induced by 5-azacytidine fell into the same complementation group as those induced by highly mutagenic carcinogens, but they were phenotypically distinct in that they were unstable during prolonged passage and rarely displayed the temperature-limited phenotypes so common among BHK transformants induced by strongly mutagenic carcinogens. These results raise the possibility that a cell can be induced by either genetic or epigenetic means to traverse the same single step in carcinogenesis.
永久性细胞系BHK-21/cl 13可因隐性体细胞突变的诱导而被诱变致癌物转化。然而，当这些细胞在无法检测到对哇巴因或6-硫鸟嘌呤耐药的突变体的条件下用5-氮杂胞苷处理时，它们被有效地转化了。这些转化体是诱导产生的，而非筛选出来的。6-氮杂胞苷对BHK细胞的转化无效；2'-脱氧-5-氮杂胞苷则异常有效。通过细胞融合试验检测时，5-氮杂胞苷诱导的转化体与高诱变致癌物诱导的转化体属于同一互补群，但它们在表型上有所不同，即它们在长时间传代过程中不稳定，并且很少表现出在强诱变致癌物诱导的BHK转化体中常见的温度限制表型。这些结果增加了一种可能性，即细胞可以通过遗传或表观遗传方式被诱导在致癌过程中跨越相同的单一阶段。
