The effect of 5-fluorouracil on DNA chain elongation in intact bone marrow cells.
The effect of 5-fluorouracil on DNA chain elongation in intact bone marrow cells.
复制标题
5-氟尿嘧啶对完整骨髓细胞 DNA 链延长的影响。
DOI：
10.1016/0006-291x(85)91884-4
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发表时间：
1985
影响因子：
3.1
通讯作者：
Diasio,RB
中科院分区：
文献类型：
--
作者：
Schuetz,JD;Diasio,RB
在完整的骨髓细胞中评估5-氟尿嘧啶（FUra）对DNA延伸的影响，所述骨髓细胞在不存在或存在FUra的情况下用[3 H]-dThd脉冲1小时，在新鲜培养基中追踪0至3小时，然后在碱性蔗糖梯度上分析。虽然来自对照细胞的DNA在3小时的间隔内以每秒86个核苷酸的平均速率伸长，但来自Fura处理的细胞的DNA在相同的间隔内没有伸长并且相反地尺寸减小。在一项平行研究中，为了检测掺入DNA的FUra发生了什么变化，骨髓细胞用50 μM [3 H]-FUra脉冲1小时，然后在新鲜培养基中追踪0 - 2小时。在碱性蔗糖梯度上裂解每个时间点的等份细胞，以评估含[3 H]-FUra的DNA的大小，同时分析来自每个时间点的另一等份细胞的总DNA中剩余的放射性。在2小时追踪期间，含有放射性标记的复制子大小DNA（≥ 100 S）的百分比降低，而小分子量DNA（≤ 7.2 S）的百分比在相同时间段内增加。DNA大小的这些变化伴随着总DNA中放射性的降低。这些研究表明，从新生DNA链中切除Fura可以防止DNA的进一步延伸。
The effect of 5-fluorouracil (FUra) on DNA elongation was assessed in intact bone marrow cells that had been pulsed for 1 hr with [3H]-dThd in the absence or presence of FUra, chased in fresh media from 0 to 3 hr, and then analyzed on alkaline sucrose gradients. While DNA from control cells elongated at an average rate of 86 nucleotides per sec over a 3 hr interval, DNA from FUra-treated cells did not elongate and in contrast decreased in size over the same interval. In a parallel study to examine what happens to the FUra that was incorporated into DNA, bone marrow cells were pulsed for 1 hr with 50 μM [3H]-FUra, and then chased in fresh media from 0 to 2 hr. An aliquot of cells from each time point was lysed on an alkaline sucrose gradient to assess the size of [3H]-FUra-containing DNA, while another aliquot of cells from each time point was analyzed for radioactivity remaining in total DNA. The percentage of replicon-size DNA (≥ 100S) containing radiolabel decreased over the 2 hr chase while the percentage of small molecular weight DNA (≤ 7.2S) increased over the same interval. These changes in DNA size were accompanied by a decrease in radioactivity in total DNA. These studies suggest that excision of FUra from nascent DNA chains may prevent further elongation of DNA.