Comet assay studies of radiation-induced DNA damage and repair in various tumour cell lines

We used the 'comet assay' to compare the amount of radiation-induced DNA damage in three tumour cell lines (MeWo, PECA 4451 and PECA 4197) and the extent of DNA repair in two of these lines (MeWo and PECA 4197). All three cell lines showed the same extent of DNA damage after radiation exposure, despite the fact that in the colony-forming assay MeWo and PECA 4451 were much more sensitive to radiation exposure than PECA 4197. The repair characteristics however, were markedly different for MeWo and PECA 4197 cells. PECA 4197 cells showed a much faster restoration of the original shape of the cell nucleus than MeWo cells. (author)