Rosenstein B S, Lai L W, Ducore J M, Rosenstein R B
Department of Radiation Medicine, Brown University, Providence, RI 02912.
Mutat Res. 1989 May;217(3):219-26. doi: 10.1016/0921-8777(89)90074-8.
DNA-protein crosslinks (DPC) were measured following exposure to the solar UV wavelengths produced by a fluorescent sunlamp in ICR 2A frog cells and two solar UV-sensitive mutants derived from this cell line. Approx. 5-7 DPC per 10(10) dalton were induced in these cells by either 150 kJ/m2 of sunlamp UV greater than 315 nm plus photoreactivating light (PRL) or 10 kJ/m2 of sunlamp UV greater than 295 nm. The irradiated cells were then incubated for 0-24 h and the level of DPC measured using alkaline elution. It was found for the ICR 2A cells exposed to sunlamp UV greater than 315 nm that the level of DPC increased about 3-fold during a 2-h postirradiation incubation and then decreased. The mutant cell lines also showed an enhancement in the level of DPC following irradiation, although it was much less pronounced and the levels decreased much more rapidly. In a similar fashion, the level of DPC increased in ICR 2A cells exposed to sunlamp UV greater than 295 nm with more than a 5-fold enhancement after a 4-h incubation. Once again, the mutant cell lines showed an increase in the level of DPC that was smaller and more transient than the effect in the ICR 2A cells. These results suggests that this enhancement in DPC may be indicative of a process that plays a role in cellular survival following solar UV-irradiation.
在ICR 2A蛙细胞以及源自该细胞系的两个对太阳紫外线敏感的突变体中，在暴露于荧光太阳灯产生的太阳紫外线波长后，测量了DNA - 蛋白质交联（DPC）。通过150 kJ/m²大于315 nm的太阳灯紫外线加光复活光（PRL）或10 kJ/m²大于295 nm的太阳灯紫外线，在这些细胞中每10¹⁰道尔顿诱导产生约5 - 7个DPC。然后将辐照后的细胞孵育0 - 24小时，并使用碱性洗脱法测量DPC水平。发现对于暴露于大于315 nm太阳灯紫外线的ICR 2A细胞，DPC水平在辐照后2小时的孵育过程中增加了约3倍，然后下降。突变细胞系在辐照后DPC水平也有所提高，尽管不太明显，且水平下降得更快。以类似的方式，暴露于大于295 nm太阳灯紫外线的ICR 2A细胞中，DPC水平在孵育4小时后增加了5倍以上。突变细胞系再次显示DPC水平的增加比ICR 2A细胞中的效应更小且更短暂。这些结果表明，DPC的这种增加可能表明一个在太阳紫外线辐照后细胞存活中起作用的过程。
