Effects of promoters on DNA synthesis in C3H/10T1/2 mouse fibroblasts.
Effects of promoters on DNA synthesis in C3H/10T1/2 mouse fibroblasts.
复制标题
启动子对 C3H/10T1/2 小鼠成纤维细胞 DNA 合成的影响。
作者：
A. R. Peterson;S. Mondal;D. Brankow;W. Thon;C. Heidelberger
本文用放射自显影法和[~ 3 H]TdR掺入法研究了培养的C_3H/10T_1/2小鼠胚胎成纤维细胞的DNA合成。首先用3-甲基胆蒽作为引发剂处理细胞，然后根据产生致癌转化的时间表用启动子处理细胞。所用的3-甲基胆蒽的水平不影响细胞的生长或[3 H]TdR掺入。在对数生长期用12-O-十四烷酰基-佛波醇-13-乙酸酯、佛波醇二癸酸酯或4 α-佛波醇二癸酸酯处理产生瞬时抑制[3 H]TdR掺入，在处理后12小时达到最大值。这导致生长暂时延迟，随后恢复正常的细胞倍增时间。佛波醇没有产生这些作用，这表明DNA合成的抑制与促进过程有关。虽然在稳定期用12-O-十四烷酰基-佛波醇-13-乙酸酯处理细胞导致[3 H]TdR掺入的2至3倍刺激，但发现跨越对数期和稳定期的多次处理对于促进是必要的。
The synthesis of DNA has been studied by autoradiography and by measurements of tritiated thymidine ([3H]TdR) incorporation in cultured C3H/10T1/2 mouse embryo fibroblasts. The cells were first treated with 3-methylcholanthrene as an initiator and then with promoters according to schedules that produce oncogenic transformation. The levels of 3-methylcholanthrene used did not affect the growth or [3H]TdR incorporation of the cells. Treatment during the log phase of growth with 12-O-tetradecanoyl-phorbol-13-acetate, phorbol didecanoate, or 4alpha-phorbol didecanoate produced a transient inhibition of [3H]TdR incorporation with the maximum at 12 hr after treatment. This resulted in a temporary delay of growth followed by recovery of the normal cell-doubling time. Phorbol did not produce these effects, suggesting that the inhibition of DNA synthesis is associated with the process of promotion. Although treatment of the cells with 12-O-tetradecanoyl-phorbol-13-acetate during stationary phase resulted in a 2- to 3-fold stimulation of [3H]TdR incorporation, multiple treatments spanning log and stationary phases were found to be necessary for promotion.