Lo K Y, Kakunaga T
Cancer Res. 1982 Jul;42(7):2644-50.
Classes of cell variants isolated from BALB/3T3-A31 clone 1 showing high, intermediate, and low susceptibility to ultraviolet light-induced transformation also demonstrated a differential response to benzo(a)pyrene (BP)-induced transformation. On the other hand, these variants showed an identical susceptibility to the killing effect of these carcinogens. The extent of BP binding to DNA was found to be very similar in all three classes of variants under transforming conditions. BP:DNA adducts from the variant cells were analyzed by high-pressure liquid chromatography. The same adducts (N2-(10S-[7R,8S,9R-trihydroxy-7,8,9,10-tetrahydrobenzo(a)pyrene]yl)deoxyguanosine and a minute amount of the 7S enantiomer) were detected in the highly susceptible, the intermediately susceptible, and the resistant variant clones. Removal of the BP:DNA adduct occurred at an equally slow rate in all three classes of variant cells. These results indicate that the formation of stable covalent DNA adducts is not a sufficient condition for induction of transformation. Processes other than formation and removal of the stably bound BP:DNA covalent adducts are thus major factors controlling the susceptibility of BALB/3T3-A31 clone 1 variant cells to BP-induced transformation.
从BALB/3T3 - A31克隆1分离出的对紫外线诱导转化表现出高、中、低敏感性的细胞变体类别，对苯并(a)芘（BP）诱导的转化也表现出不同的反应。另一方面，这些变体对这些致癌物的杀伤作用表现出相同的敏感性。发现在转化条件下，所有三类变体中BP与DNA的结合程度非常相似。通过高压液相色谱分析变体细胞中的BP:DNA加合物。在高敏感性、中等敏感性和抗性变体克隆中检测到相同的加合物（N2 - (10S - [7R,8S,9R - 三羟基 - 7,8,9,10 - 四氢苯并(a)芘]基)脱氧鸟苷和少量的7S对映体）。在所有三类变体细胞中，BP:DNA加合物的去除速率同样缓慢。这些结果表明，稳定的共价DNA加合物的形成不是诱导转化的充分条件。因此，除了稳定结合的BP:DNA共价加合物的形成和去除之外的过程是控制BALB/3T3 - A31克隆1变体细胞对BP诱导转化敏感性的主要因素。
