Studies on age-dependency of radiation-induced mutation and its mechanism

虽然公认辐射诱发的癌症与个人受照射的年龄有关，但其机制尚不清楚。我们推测，年龄依赖性可以解释为辐射诱导突变效率的差异。利用lacZ转基因小鼠，我们研究了不同年龄的肝脏突变诱导的剂量反应。其效率随年龄变化，但变化方式与诱癌不同。因此，突变诱导不能解释癌症诱导的年龄依赖性。

Although it is well established that radiation-induced cancer shows age-dependency at which the individuals are exposed, the mechanism responsible for it is not understood. We hypothesized that the age-dependency could be explained by a difference in the efficiency of mutation induction with radiation. Using lacZ-transgenic mice, we studied dose responses of mutation induction in liver at different ages. The efficiency changed with age but the mode of the change was different from that of cancer induction. Thus, mutation induction could not explain the age-dependency of cancer induction.