Poly(ADP-ribose) and the recovery from damage in Chinese hamster cells due to 5-bromodeoxyuridine photolysis.
Poly(ADP-ribose) and the recovery from damage in Chinese hamster cells due to 5-bromodeoxyuridine photolysis.
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聚（ADP-核糖）和中国仓鼠细胞因 5-溴脱氧尿苷光解作用而损伤的恢复。
DOI：
10.1080/09553008514551041
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Elkind,MM
中科院分区：
文献类型：
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作者：
Ben-Hur,E;Lindquist,K;Elkind,MM
将5-溴脱氧尿苷（BrdUrd）均匀掺入中国仓鼠细胞的DNA后，将中国仓鼠细胞暴露于近紫外光下，导致细胞杀伤接近指数级。聚（ADP-核糖）合成的抑制剂，3-氨基苯甲酰胺（3-阿坝），增强了这种治疗的细胞毒性作用时，在20毫米曝光后存在2小时。剂量修正因子为1·4。在导致S形存活曲线的条件下（S期30分钟BrdUrd脉冲，90分钟后曝光），3-阿坝的作用是去除存活曲线的肩部，其最终斜率变化很小。使用ADP-核糖基转移酶（ADPRT）的各种抑制剂，发现增强的细胞杀伤与抑制剂的相对效力相关。细胞NAD+，聚（ADP-核糖）合成的底物，暴露后迅速耗尽。这种消耗在很大程度上防止3-阿坝; ADPRT的活性增加与近紫外线的能量密度;和细胞NAD+的浓度降低曝光。ADPRT活性在暴露于近紫外光后立即达到最大值，然后在30 min（37°C）内衰减至暴露前水平。增强的细胞毒性的BrdUrd +近紫外光，随后3-阿坝处理，消失的速度类似的衰减ADPRT活性。我们得出结论，从这些结果，聚（ADP-核糖）的合成是重要的BrdUrd光解损伤DNA的恢复。由于这种损伤及其修复是相对特异性的（例如，与电离辐射相比），并且相对容易操作，因此它可以作为研究聚（ADP-核糖）在DNA损伤修复中的作用的模型系统。
Exposure of Chinese hamster cells to near-u.v. light, following the uniform incorporation of 5-bromodeoxyuridine (BrdUrd) into their DNA, resulted in cell killing that was close to exponential. An inhibitor of poly(ADP-ribose) synthesis, 3-aminobenzamide (3-ABA), enhanced the cytotoxic effect of this treatment when present for 2 h at 20 mm after light exposure. The dose modifying factor was 1·4. Under conditions that resulted in a sigmoidal survival curve (a 30 min BrdUrd pulse in S phase, followed 90 min later by light exposure) the effect of 3-ABA was to remove the shoulder of the survival curve with very little change in its final slope. Using various inhibitors of ADP-ribosyl transferase (ADPRT) the enhanced cell killing was found to correlate with the inhibitors' relative potency. Cellular NAD+, the substrate for poly(ADP-ribose) synthesis, was rapidly depleted after exposure. This depletion was largely prevented by 3-ABA; the activity of ADPRT increased with the fluence of near-u.v. light; and the concentration of cellular NAD+decreased with exposure. ADPRT activity was maximal immediately after exposure to near u.v. light and then decayed to preexposure levels within 30 min (37°C). The enhanced cytotoxicity of BrdUrd + near-u.v. light, when followed by 3-ABA treatment, disappeared at a rate similar to that of the decay in ADPRT activity. We conclude from these results that poly(ADP-ribose) synthesis is important for the recovery from BrdUrd photolysis damage in DNA. Because this damage and its repair are relatively specific (e.g. compared to ionizing radiation) and relatively easy to manipulate, it could serve as a model system for the study of the role of poly(ADP-ribose) in the repair of DNA damage.