Assessment of the genotoxic potential of nitric oxide-induced guanine lesions by in vitro reactions with Escherichia coli DNA polymerase I
Open Access
- 20 April 2005
- journal article
- research article
- Published by Oxford University Press (OUP) in Mutagenesis
- Vol. 20 (3), 209-216
- https://doi.org/10.1093/mutage/gei027
Abstract
It has been suggested that carcinogenesis associated with chronic inflammation involves DNA damage by nitric oxide (NO) and other reactive species secreted from macrophages and neutrophils. The guanine moiety of DNA reacts with NO, yielding two major deamination products: xanthine (Xan) and oxanine (Oxa). Oxa reacts further with polyamines and DNA binding proteins to form cross-link adducts. In the present study, we characterized the structure of the cross-link adducts of Oxa with spermine (Oxa-Sp). Spectrometric analysis of Oxa-Sp adducts showed that they are ring-opened adducts of Oxa covalently bonded to the terminal amino (major product) and internal imino (minor product) groups of spermine. To assess genotoxic potential, Xan, Oxa, Oxa-Sp and an abasic (AP) site were site specifically incorporated into oligonucleotide templates. These lesions differentially blocked in vitro DNA synthesis catalyzed by DNA polymerase I Klenow fragment (Pol I Kf). The relative efficiency of translesion synthesis was G (1) > Oxa (0.19) > Xan (0.12) > AP (0.088) > Oxa-Sp (0.035). Primer extension assays with a single nucleotide and Pol I Kf revealed that non-mutagenic dCMP was inserted most efficiently opposite Xan and Oxa, with the extent of primer elongation being 65% for Xan and 68% for Oxa. However, mutagenic nucleotides were also inserted. The extent of primer elongation for Xan was 16% with dTMP and 14% with dGMP, whereas that for Oxa was 49% with dTMP. For Oxa-Sp, mutagenic dAMP (13%) was preferentially inserted. Accordingly, when generated in vivo, Xan and Oxa would constitute moderate blocks to DNA synthesis and primarily elicit G:C to A:T transitions when bypassed, whereas Oxa-Sp would strongly block DNA synthesis and elicit G:C to T:A transversions.Keywords
This publication has 51 references indexed in Scilit:
- Nitrosative Guanine Deamination: Ab Initio Study of Deglycation of N-Protonated 5-Cyanoimino-4-oxomethylene-4,5-dihydroimidazolesChemical Research in Toxicology, 2004
- Uracil in DNA – occurrence, consequences and repairOncogene, 2002
- Recombinational Repair Is Critical for Survival of Escherichia coli Exposed to Nitric OxideJournal of Bacteriology, 2001
- Effects of nitrous acid treatment on the survival and mutagenesis of Escherichia coli cells lacking base excision repair(hypoxanthine-DNA glycosylase-ALK A protein) and/or nucleotide excision repairMutagenesis, 1997
- DNA Damage by Nitric OxideChemical Research in Toxicology, 1996
- Pyrimidine Ring Fragmentation Products: Effects of Lesion Structure and Sequence Context on MutagenesisJournal of Molecular Biology, 1994
- Molecular models that may account for nitrous acid mutagenesis in organisms containing double‐stranded DNAEnvironmental and Molecular Mutagenesis, 1994
- Mutagenicity of nitric oxide is not caused by deamination of cytosine or 5-methylcytosine in double-stranded DNACarcinogenesis: Integrative Cancer Research, 1994
- In vitro Replication Study of Modified bases in ras Sequences.CHEMICAL & PHARMACEUTICAL BULLETIN, 1992
- DNA Deaminating Ability and Genotoxicity of Nitric Oxide and its ProgenitorsScience, 1991