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UNSCHEDULED DNA SYNTHESIS: A QUANTITATIVE INDICATOR OF RESIDUAL IMMUNODETECTABLE PYRIMIDINE DIMERS IN HUMAN FIBROBLASTS AFTER ULTRAVIOLET‐B IRRADIATION
Author(s) -
PLAZA SERGE,
BOULLARD ANNIE,
PELÉ DOMINIQUE,
CORNELIS JAN J.,
ROMMELAERE JEAN,
GIACOMONI PAOLO U.,
PRUNIERAS MICHEL
Publication year - 1991
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1991.tb03926.x
Subject(s) - pyrimidine dimer , irradiation , pyrimidine , incubation , microbiology and biotechnology , dna , dna damage , in vitro , photolyase , ultraviolet , chemistry , dna repair , biology , photochemistry , biochemistry , materials science , physics , optoelectronics , nuclear physics
— We have addressed the question whether the level of UV‐B induced DNA damage can be accurately assessed by the measurement of the rate of unscheduled DNA synthesis (UDS). Cultured human fibroblasts were irradiated with UV radiation at 290, 313 or 365 nm. The LD 50 was 85 J/m 2 at 290 nm, 4500 J/m 2 at 313 nm, and 70 kJ/m 2 at 365 nm. The analysis of UDS measurements indicate complete arrest of repair processes within 24 h after irradiation, irrespective of the dose (in the range 10–60 J/m 2 at 290 nm, and 250–1000 J/m 2 at 313 nm). Irradiation at 365 nm failed to yield detectable evidence of UDS. Incubation of irradiated cells with an antiserum directed against both 6–4 type and cyclobutane‐type pyrimidine dimers shows a clear parallelism between the disappearance of the antibody‐binding determinants and the variation of the rate of UDS vs time after the end of the irradiation. Thus it is concluded that in UV‐B irradiated normal cultured human fibroblasts, the lack of UDS reflects the absence of immunodetectable pyrimidine dimers.