Genotoxic potential of psoralen cross-links versus monoadducts in normal human lymphoblasts.
Using the 4,5',8-trimethylpsoralen in combination with the reirradiation protocol, we show that, in normal human lymphoblasts, the cytotoxic potential of photoinduced cross-links (CL) is higher than that of monoadducts (MA). In contrast to cytotoxicity, the significant increase in the proportion of CL, at a constant level of total adducts, had no effect on the induction of mutations at the HPRT locus. Comparison with the data obtained in yeast and rodent cells using the same double irradiation protocol shows that the mutagenic potential of CL versus MA varies between species. This suggests that the equilibrium between the excision, the recombinational and the mutagenic components of the repair pathways which probably determine the mutagenic efficiency of CL versus MA is likely to be species-dependent.
Laquerbe
A
A
Institut Curie-Biologie, URA 1292 CNRS, Paris, France.
Moustacchi
E
E
Papadopoulo
D
D
D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D018736:DNA Adducts; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics*; D008214:Lymphocytes / Q000187:drug effects* / Q000528:radiation effects; D009152:Mutagenicity Tests; D009154:Mutation; D013045:Species Specificity; D014307:Trioxsalen / Q000633:toxicity*; D014466:Ultraviolet Rays
D018736:DNA Adducts; D007041:Hypoxanthine Phosphoribosyltransferase; D014307:Trioxsalen