XERODERMA PIGMENTOSUM CELLS WITH NORMAL LEVELS OF EXCISION REPAIR HAVE A DEFECT IN DNA-SYNTHESIS AFTER UV-IRRADIATION
XERODERMA PIGMENTOSUM CELLS WITH NORMAL LEVELS OF EXCISION REPAIR HAVE A DEFECT IN DNA-SYNTHESIS AFTER UV-IRRADIATION
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DOI：
10.1073/pnas.72.1.219
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发表时间：
1975-01-01
影响因子：
11.1
通讯作者：
BOOTSMA, D
中科院分区：
文献类型：
--
作者：
LEHMANN, AR;KIRKBELL, S;BOOTSMA, D
大多数患有日光敏感型遗传性疾病着色性干皮病的患者培养的细胞在从DNA中去除紫外线(UV)诱导的嘧啶二聚体的能力存在缺陷。然而，有一类患者的细胞在切除修复过程中是完全正常的。我们发现，这些细胞在紫外线照射后合成DNA的方式出现了异常。在紫外线照射的细胞中，将最初合成的低分子DNA转化为大小与未处理细胞相似的高分子DNA所需的时间在这些变体中比正常细胞中要长得多。此外，新合成的低分子DNA向高分子DNA的缓慢转化被咖啡因显著抑制，而咖啡因对正常细胞没有影响。来自两类色素性干皮病的细胞系在切除修复方面存在缺陷，在将新合成的DNA转化为高分子量DNA所需的时间和咖啡因对这一过程的抑制方面都显示出中等效果。
Cells cultured from most patients suffering from the sunlight-sensitive hereditary disorder xeroderma pigmentosum are defective in the ability to excise ultraviolet light (UV)-induced pyrimidine dimers from their DNA. There is, however, one class of these patients whose cells are completely normal in this excision repair process. We have found that these cells have an abnormality in the manner in which DNA is synthesized after UV-irradiation. The time taken to convert initially low-molecular-weight DNA synthesized in UV-irradiated cells into high-molecular-weight DNA similar in size to that in untreated cells is much greater in these variants than in normal cells. Furthermore, this slow conversion of low to high-molecular-weight newly synthesized DNA is drastically inhibited by caffeine, which has no effect in normal cells. Two cell lines from classes of xeroderma pigmentosum that are defective in excision-repair show intermediate effects, with regard to both the time taken to convert newly synthesized DNA to high molecular weight and the inhibition of this process by caffeine.