Ciarrocchi G, Linn S
Proc Natl Acad Sci U S A. 1978 Apr;75(4):1887-91. doi: 10.1073/pnas.75.4.1887.
Osmotic disruption of confluent cultured human fibroblasts that have been irradiated or exposed to chemical carcinogens allows the specific measurement of repair DNA synthesis using dTTP as a precursor. Fibroblasts similarly prepared from various xeroderma pigmentosum cell lines show the deficiencies of UV-induced DNA synthesis predicted from in vivo studies, while giving normal responses to methyl methanesulfonate. A pyrimidine-dimer-specific enzyme, T4 endonuclease V, stimulated the rate of UV-induced repair synthesis with normal and xeroderma pigmentosum cell lines. This system should prove useful for identifying agents that induce DNA repair, and cells that respond abnormally to such induction. It should also be applicable to an in vitro complementation assay with repair-defective cells and proteins obtained from repair-proficient cells. Finally, by using actively growing fibroblasts and thymidine in the system, DNA replication can be measured and studied in vitro.
对已照射或暴露于化学致癌物的汇合培养的人成纤维细胞进行渗透破坏,可使用dTTP作为前体来特异性测量修复DNA合成。从各种着色性干皮病细胞系中同样制备的成纤维细胞显示出体内研究预测的紫外线诱导的DNA合成缺陷,而对甲磺酸甲酯则有正常反应。一种嘧啶二聚体特异性酶,T4内切核酸酶V,刺激了正常和着色性干皮病细胞系中紫外线诱导的修复合成速率。该系统应被证明可用于鉴定诱导DNA修复的试剂以及对这种诱导反应异常的细胞。它也应适用于与修复缺陷细胞和从修复 proficient细胞获得的蛋白质进行的体外互补分析。最后,通过在系统中使用活跃生长的成纤维细胞和胸苷,可以在体外测量和研究DNA复制。