Aflatoxin B1-induced DNA damage and its repair.
Aflatoxin B(1) (AFB(1))-N(7)-guanine is the predominant adduct formed upon the reaction of AFB(1)-8,9-exo-epoxide with guanine residues in DNA. AFB(1)-N(7)-guanine can convert to the ring-opened formamidopyrimidine, or the adducted strand can undergo depurination. AFB(1)-N(7)-guanine and AFB(1)-formamidopyrimidine are thought to be predominantly repaired by nucleotide excision repair in bacteria, yeast and mammals. Although AFB(1)-formamidopyrimidine is removed less efficiently than AFB(1)-N(7)-guanine in mammals, both lesions are repaired with equal efficiencies in bacteria, reflecting differences in damage recognition between bacterial and mammalian repair systems. Furthermore, DNA repair activity and modulation of repair by AFB(1) seem to be major determinants of susceptibility to AFB(1)-induced carcinogenesis.
Bedard
Leanne L
LL
Department of Pharmacology and Toxicology, Queen's University, Botterell Hall, Kingston, Ont., Canada K7L 3N6.
Massey
Thomas E
TE
D016604:Aflatoxin B1 / Q000494:pharmacology*; D000818:Animals; D004249:DNA Damage / Q000187:drug effects*; D004260:DNA Repair; D006801:Humans
D016604:Aflatoxin B1