M. Klaude et al., DNA-DAMAGE AND REPAIR AFTER LOW-DOSES OF UV-C RADIATION - COMPARABLE RATES OF REPAIR IN RODENT AND HUMAN-CELLS, International journal of radiation biology, 67(5), 1995, pp. 501-508
Citations number
36
Categorie Soggetti
Radiology,Nuclear Medicine & Medical Imaging","Nuclear Sciences & Tecnology
The UV endonuclease assay for cyclobutane pyrimidine dimers in the DNA
of UV-C-irradiated mammalian cells has been modified by replacing alk
aline sucrose sedimentation with alkaline unwinding and hydroxylapatit
e chromatography to determine the number of DNA breaks introduced by t
he endonuclease. Dimers induced by doses as low as 0.25 Jm(-2) can be
detected and the assay has been used to examine the capacity of human,
hamster and mouse cells to remove damage inflicted by sublethal doses
of UV-C. In addition, incision activity has been measured by incubati
ng cells with DNA synthesis inhibitors after irradiation with UV-C. In
rodent and human cells, given a dose of UV-C of 1 Jm(-2) about half o
f the endonuclease-sensitive sites are lost in 5-6 h. The incision cap
acity of these cells corresponds well with the extent of removal of di
mers. Thus, although rodent cells are normally considered to be relati
vely deficient in nucleotide excision repair, we find that rodent and
human cells have comparable capacities to deal with low levels of UV-C
-induced damage.