Broughton B C, Lehmann A R, Harcourt S A, Arlett C F, Sarasin A, Kleijer W J, Beemer F A, Nairn R, Mitchell D L
MRC Cell Mutation Unit, University of Sussex, Falmer, Brighton, Great Britain.
Mutat Res. 1990 Jan;235(1):33-40. doi: 10.1016/0921-8777(90)90020-6.
Trichothiodystrophy is a genetic disease which in the majority of cases studied is associated with a deficiency in the ability to repair UV damage in cellular DNA. Three categories of UV response have been identified. In type 1 the response is completely normal, whereas type 2 cells are deficient in excision-repair, with properties indistinguishable from those of XP complementation group D. Type 3 cells have normal survival following UV-irradiation and normal rates of removal of cyclobutane pyrimidine dimer sites. Nevertheless repair synthesis is reduced by 50% in these cell strains and this is associated with a marked reduction in the repair of 6-4 photoproducts from cellular DNA. The present results show that 50% or more of repair synthesis at early times after irradiation of normal primary human fibroblasts is attributable to repair of 6-4 products. They also suggest that repair of cyclobutane dimers is crucial for cell survival.
毛发硫营养不良是一种遗传性疾病，在大多数已研究的病例中，它与细胞DNA中修复紫外线损伤的能力缺陷有关。已确定了三类紫外线反应。在1型中，反应完全正常，而2型细胞在切除修复方面存在缺陷，其特性与着色性干皮病互补组D的细胞无法区分。3型细胞在紫外线照射后具有正常的存活率，并且环丁烷嘧啶二聚体位点的去除率正常。然而，在这些细胞株中，修复合成减少了50%，这与细胞DNA中6-4光产物修复的显著减少有关。目前的结果表明，正常原代人成纤维细胞照射后早期50%或更多的修复合成归因于6-4产物的修复。它们还表明，环丁烷二聚体的修复对细胞存活至关重要。
