Matthews E J
Center for Food Safety and Applied Nutrition, Food and Drug Administration, Washington, DC 20204.
Environ Health Perspect. 1993 Jul;101 Suppl 2(Suppl 2):277-91. doi: 10.1289/ehp.93101s2277.
The frequency of spontaneous morphological transformation is an important variable in measuring chemical-induced transformation in BALB/c-3T3 clone A-31-1-13 cell cultures. Data from 110 experiments, which included benzo[a]pyrene control groups and other chemical treatment groups, were analyzed for factors that influenced spontaneous transformation. Spontaneous transformants demonstrated a continuum of morphological variants (type I, II, and III foci) that fit a normal distribution if converted to log10. The magnitude of transformation depended on the ampule of cryopreserved cells and the serum lot. Although the average frequency was approximately 0.71 x 10(-6) (type III foci/cell that survived and proliferated to confluence), the absolute number of foci/vessel increased in proportion to the surface area of the culture vessel. Thus, the frequency of spontaneous transformation was directly related to the cumulative number of mitoses that occurred in forming the contact-inhibited monolayer. These data are consistent with a hypothesis that spontaneous transformation in BALB/c-3T3 cells is a mutational event or some other single-step phenomenon.
在测量BALB/c - 3T3克隆A - 31 - 1 - 13细胞培养物中化学诱导的转化时，自发形态转化的频率是一个重要变量。对110个实验的数据进行了分析，这些实验包括苯并[a]芘对照组和其他化学处理组，以找出影响自发转化的因素。自发转化体表现出一系列形态变体（I型、II型和III型病灶），如果转换为log10，则符合正态分布。转化的程度取决于冷冻保存细胞的安瓿和血清批次。虽然平均频率约为0.71×10⁻⁶（III型病灶/存活并增殖至汇合的细胞），但每个培养皿中病灶的绝对数量与培养皿的表面积成比例增加。因此，自发转化的频率与形成接触抑制单层时发生的有丝分裂总数直接相关。这些数据与一个假设一致，即BALB/c - 3T3细胞中的自发转化是一种突变事件或其他单步现象。
