Caffeine-inhibited DNA repair in 7-bromomethylbenz (a) -anthracene-treated Chinease hamster cells: formation of breaks in parental DNA and inhibition of ligation of nascent DNA as a mechanism for enhancement of lethality and chromosome damage
Friedlos, F.; Roberts, J.J.
Mutation Research 50(2): 263-275
1978
ISSN/ISBN: 0027-5107 PMID: 651940 Document Number: 130837
The cytotoxic and clastogenic effects of 7-bromomethylbenz(a)anthracene (7-BMBA) are potentiated by post-treatment incubation of cells in the presence of a non-toxic concentration of caffeine. Caffeine inhibits the rate of ligation of newly-synthesized DNA and induces breaks in the template strand of DNA. Endonucleolytic attack evidently occurs at the site of lesions in the template strand of DNA and a later step(s) of excision-repair is (are) inhibited by the presence of caffeine-induced gaps in the nascent DNA opposite these lesions.