Polycyclic aromatic hydrocarbon 0-quinones mutate p53 in human lung adenocarcinoma (a549) cells

摘要

Human lung adenocarcinoma (A549) cells form reactive and redox active PAH-o-quinones via constitutively expressed aldo-keto reductases.To determine whether these metabolites mutate p53,A549 cells were treated with N-methyl-N-nitroso-N-nitroguanidine (MNNG an alkylating rnutagen),anti-BPDE (diol-epoxide) and benzo[a]pyrene-7,8-dione (o-quinone).p53 cDNA was amplified from the treated cells and cotransfected with a gap-repair plasmid designed to express p53 in yeast.When mutant p5 3 is expressed,it fails to drive the expression of an ADE2 reporter,and the yeast strain ylG397 turns red.The following mutational frequencies were observed versus the solvent controls:1 mM MNNG (24.2% red colonies p = .02),1 n.M anti-BPDE (9.9% red colonies p = .02),and 10 n.M BP-7,8-dione (9.3% red colonies p = .03).MNNG gave a high frequency (49%) of the expected C > T(G > A) mutationsip = .25).While anti-BPDE and BP-7,8-dione gave A> G(T> C) transitions (p = .034 - p - .054).These mutations would result from stable N~6-deoxyadenosine adducts,but not from oxidatively damaged bases.