Mutagenesis by acrolein-derived propanodeoxyguanosine adducts in human cells.
Acrolein, which is widely spread in the environment and is produced by lipid peroxidation in cells, reacts with DNA to form two exocyclic 1,N2-propanodeoxyguanosine (PdG) adducts. To establish their relative contribution to the acrolein mutagenicity, the genotoxic properties of alpha-OH-PdG and gamma-OH-PdG together with their model DNA adduct, PdG, were studied in human cells. DNA adducts were incorporated site-specifically into a SV40/BK virus origin-based shuttle vector and replicated in xeroderma pigmentosum complementation group A (XPA) cells. Analysis of progeny plasmid revealed that alpha-OH-PdG and PdG strongly block DNA synthesis and that both adducts induced base substitutions with G --> T transversions predominating. Primer extension studies, catalyzed by the 3'-->5' exonuclease-deficient Klenow fragment of Escherichia coli pol I, revealed limited extension from the 3' primer termini opposite these two adducts. In contrast, gamma-OH-PdG did not strongly block DNA synthesis or miscode in XPA cells. Primer extension from a dC terminus opposite gamma-OH-PdG was much more efficient than that opposite alpha-OH-PdG or PdG. These results indicate that the minor alpha-OH-PdG adduct is more genotoxic than the major gamma-OH-PdG. Furthermore, experiments using a HeLa whole cell extract indicate that all three DNA adducts are not efficiently removed from DNA by base excision repair.
Yang
In-Young
IY
Laboratory of Chemical Biology, State University of New York, Stony Brook, New York 11794-8651, USA.
Chan
Grace
G
Miller
Holly
H
Huang
Yanhe
Y
Torres
Maria Cecilia
MC
Johnson
Francis
F
Moriya
Masaaki
M
D000171:Acrolein / Q000378:metabolism / Q000494:pharmacology*; D020137:Base Pair Mismatch; D018736:DNA Adducts / Q000187:drug effects* / Q000378:metabolism; D004249:DNA Damage; D017931:DNA Primers / Q000737:chemistry; D004260:DNA Repair; D004261:DNA Replication / Q000187:drug effects; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics; D005822:Genetic Vectors; D006367:HeLa Cells / Q000187:drug effects; D006801:Humans; D016296:Mutagenesis; D014983:Xeroderma Pigmentosum / Q000235:genetics / Q000378:metabolism
D018736:DNA Adducts; D017931:DNA Primers; C424742:OH-1,-N(2)-propano-2'-deoxyguanosine; C060934:1,N(2)-propanodeoxyguanosine; D000171:Acrolein; D003849:Deoxyguanosine