Abstract
The 7-methylguanine adduct in the DNA of rat liver is determined as an indicator of exposure to exogenous and endogenous methylating agents. A method for the analysis of 7-methylguanine adducts has been developed by combining the selectivity of separation of reversed-phase HPLC with the specificity and high sensitivity of electrochemical detection. The sensitivity of the method is about 10,000-fold that of optical methods and is sufficient to determine the endogenous background of DNA methylation. DNA from the liver of normal young rats (6 months old) contains 7-methylguanine at a level of 1 residue per 31,000 bases in mitochondrial DNA and 1 residue per 105,000 bases in nuclear DNA. These levels increase about 2.5-fold in old rats (24 months old). We attribute this strikingly high level of adducts to endogenous methylation, which could contribute to aging and cancer.
Full text
PDF



Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Adelman R., Saul R. L., Ames B. N. Oxidative damage to DNA: relation to species metabolic rate and life span. Proc Natl Acad Sci U S A. 1988 Apr;85(8):2706–2708. doi: 10.1073/pnas.85.8.2706. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ames B. N. Dietary carcinogens and anticarcinogens. Oxygen radicals and degenerative diseases. Science. 1983 Sep 23;221(4617):1256–1264. doi: 10.1126/science.6351251. [DOI] [PubMed] [Google Scholar]
- Backer J. M., Weinstein I. B. Interaction of benzo(a)pyrene and its dihydrodiol-epoxide derivative with nuclear and mitochondrial DNA in C3H10T 1/2 cell cultures. Cancer Res. 1982 Jul;42(7):2764–2769. [PubMed] [Google Scholar]
- Backer J. M., Weinstein I. B. Mitochondrial DNA is a major cellular target for a dihydrodiol-epoxide derivative of benzo[a]pyrene. Science. 1980 Jul 11;209(4453):297–299. doi: 10.1126/science.6770466. [DOI] [PubMed] [Google Scholar]
- Barrows L. R., Magee P. N. Nonenzymatic methylation of DNA by S-adenosylmethionine in vitro. Carcinogenesis. 1982;3(3):349–351. doi: 10.1093/carcin/3.3.349. [DOI] [PubMed] [Google Scholar]
- Boiteux S., Laval J. Imidazole open ring 7-methylguanine: an inhibitor of DNA synthesis. Biochem Biophys Res Commun. 1983 Jan 27;110(2):552–558. doi: 10.1016/0006-291x(83)91185-3. [DOI] [PubMed] [Google Scholar]
- Brookes P., Lawley P. D. The reaction of mono- and di-functional alkylating agents with nucleic acids. Biochem J. 1961 Sep;80(3):496–503. doi: 10.1042/bj0800496. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chetsanga C. J., Lozon M., Makaroff C., Savage L. Purification and characterization of Escherichia coli formamidopyrimidine-DNA glycosylase that excises damaged 7-methylguanine from deoxyribonucleic acid. Biochemistry. 1981 Sep 1;20(18):5201–5207. doi: 10.1021/bi00521a016. [DOI] [PubMed] [Google Scholar]
- Clayton D. A., Doda J. N., Friedberg E. C. The absence of a pyrimidine dimer repair mechanism in mammalian mitochondria. Proc Natl Acad Sci U S A. 1974 Jul;71(7):2777–2781. doi: 10.1073/pnas.71.7.2777. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Floyd R. A., Watson J. J., Wong P. K., Altmiller D. H., Rickard R. C. Hydroxyl free radical adduct of deoxyguanosine: sensitive detection and mechanisms of formation. Free Radic Res Commun. 1986;1(3):163–172. doi: 10.3109/10715768609083148. [DOI] [PubMed] [Google Scholar]
- Frei B., Winterhalter K. H., Richter C. Mechanism of alloxan-induced calcium release from rat liver mitochondria. J Biol Chem. 1985 Jun 25;260(12):7394–7401. [PubMed] [Google Scholar]
- Gaubatz J. W. DNA damage during aging of mouse myocardium. J Mol Cell Cardiol. 1986 Dec;18(12):1317–1320. doi: 10.1016/s0022-2828(86)80435-7. [DOI] [PubMed] [Google Scholar]
- Gold M., Hurwitz J., Anders M. THE ENZYMATIC METHYLATION OF RNA AND DNA, II. ON THE SPECIES SPECIFICITY OF THE METHYLATION ENZYMES. Proc Natl Acad Sci U S A. 1963 Jul;50(1):164–169. doi: 10.1073/pnas.50.1.164. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gupta R. C. Nonrandom binding of the carcinogen N-hydroxy-2-acetylaminofluorene to repetitive sequences of rat liver DNA in vivo. Proc Natl Acad Sci U S A. 1984 Nov;81(22):6943–6947. doi: 10.1073/pnas.81.22.6943. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hadler H. I., Dimitrijevic B., Mahalingam R. Mitochondrial DNA and nuclear DNA from normal rat liver have a common sequence. Proc Natl Acad Sci U S A. 1983 Nov;80(21):6495–6499. doi: 10.1073/pnas.80.21.6495. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Harman D. The aging process. Proc Natl Acad Sci U S A. 1981 Nov;78(11):7124–7128. doi: 10.1073/pnas.78.11.7124. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hollstein M. C., Brooks P., Linn S., Ames B. N. Hydroxymethyluracil DNA glycosylase in mammalian cells. Proc Natl Acad Sci U S A. 1984 Jul;81(13):4003–4007. doi: 10.1073/pnas.81.13.4003. [DOI] [PMC free article] [PubMed] [Google Scholar]
- KRIEK E., EMMELOT P. METHYLATION OF DEOXYRIBONUCLEIC ACID BY DIAZOMETHANE. Biochim Biophys Acta. 1964 Sep 11;91:59–66. doi: 10.1016/0926-6550(64)90170-7. [DOI] [PubMed] [Google Scholar]
- Karran P., Lindahl T. Hypoxanthine in deoxyribonucleic acid: generation by heat-induced hydrolysis of adenine residues and release in free form by a deoxyribonucleic acid glycosylase from calf thymus. Biochemistry. 1980 Dec 23;19(26):6005–6011. doi: 10.1021/bi00567a010. [DOI] [PubMed] [Google Scholar]
- Kasai H., Nishimura S., Kurokawa Y., Hayashi Y. Oral administration of the renal carcinogen, potassium bromate, specifically produces 8-hydroxydeoxyguanosine in rat target organ DNA. Carcinogenesis. 1987 Dec;8(12):1959–1961. doi: 10.1093/carcin/8.12.1959. [DOI] [PubMed] [Google Scholar]
- Kunkel T. A., Shearman C. W., Loeb L. A. Mutagenesis in vitro by depurination of phiX174 dna. Nature. 1981 May 28;291(5813):349–351. doi: 10.1038/291349a0. [DOI] [PubMed] [Google Scholar]
- LAWLEY P. D., BROOKES P. FURTHER STUDIES ON THE ALKYLATION OF NUCLEIC ACIDS AND THEIR CONSTITUENT NUCLEOTIDES. Biochem J. 1963 Oct;89:127–138. doi: 10.1042/bj0890127. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lampidis T. J., Schaiberger G. E. Age-related loss of DNA repair synthesis in isolated rat myocardial cells. Exp Cell Res. 1975 Dec;96(2):412–416. doi: 10.1016/0014-4827(75)90276-1. [DOI] [PubMed] [Google Scholar]
- Laval J., Pierre J., Laval F. Release of 7-methylguanine residues from alkylated DNA by extracts of Micrococcus luteus and Escherichia coli. Proc Natl Acad Sci U S A. 1981 Feb;78(2):852–855. doi: 10.1073/pnas.78.2.852. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lawley P. D., Orr D. J. Specific excision of methylation products from DNA of Escherichia coli treated with N-methyl-N'-nitro-N-nitrosoguanidine. Chem Biol Interact. 1970 Aug;2(2):154–157. doi: 10.1016/0009-2797(70)90047-5. [DOI] [PubMed] [Google Scholar]
- Lindahl T. DNA repair enzymes. Annu Rev Biochem. 1982;51:61–87. doi: 10.1146/annurev.bi.51.070182.000425. [DOI] [PubMed] [Google Scholar]
- Lindahl T., Nyberg B. Rate of depurination of native deoxyribonucleic acid. Biochemistry. 1972 Sep 12;11(19):3610–3618. doi: 10.1021/bi00769a018. [DOI] [PubMed] [Google Scholar]
- Margison G. P., Pegg A. E. Enzymatic release of 7-methylguanine from methylated DNA by rodent liver extracts. Proc Natl Acad Sci U S A. 1981 Feb;78(2):861–865. doi: 10.1073/pnas.78.2.861. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Myers K. A., Saffhill R., O'Connor P. J. Repair of alkylated purines in the hepatic DNA of mitochondria and nuclei in the rat. Carcinogenesis. 1988 Feb;9(2):285–292. doi: 10.1093/carcin/9.2.285. [DOI] [PubMed] [Google Scholar]
- Prakash L. Repair of pyrimidine dimers in nuclear and mitochondrial DNA of yeast irradiated with low doses of ultraviolet light. J Mol Biol. 1975 Nov 15;98(4):781–795. doi: 10.1016/s0022-2836(75)80010-6. [DOI] [PubMed] [Google Scholar]
- Prakash L., Strauss B. Repair of alkylation damage: stability of methyl groups in Bacillus subtilis treated with methyl methanesulfonate. J Bacteriol. 1970 Jun;102(3):760–766. doi: 10.1128/jb.102.3.760-766.1970. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Randerath K., Reddy M. V., Disher R. M. Age- and tissue-related DNA modifications in untreated rats: detection by 32P-postlabeling assay and possible significance for spontaneous tumor induction and aging. Carcinogenesis. 1986 Sep;7(9):1615–1617. doi: 10.1093/carcin/7.9.1615. [DOI] [PubMed] [Google Scholar]
- Randerath K., Reddy M. V., Gupta R. C. 32P-labeling test for DNA damage. Proc Natl Acad Sci U S A. 1981 Oct;78(10):6126–6129. doi: 10.1073/pnas.78.10.6126. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Richter C., Park J. W., Ames B. N. Normal oxidative damage to mitochondrial and nuclear DNA is extensive. Proc Natl Acad Sci U S A. 1988 Sep;85(17):6465–6467. doi: 10.1073/pnas.85.17.6465. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rydberg B., Lindahl T. Nonenzymatic methylation of DNA by the intracellular methyl group donor S-adenosyl-L-methionine is a potentially mutagenic reaction. EMBO J. 1982;1(2):211–216. doi: 10.1002/j.1460-2075.1982.tb01149.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Saffhill R., Margison G. P., O'Connor P. J. Mechanisms of carcinogenesis induced by alkylating agents. Biochim Biophys Acta. 1985 Dec 17;823(2):111–145. doi: 10.1016/0304-419x(85)90009-5. [DOI] [PubMed] [Google Scholar]
- Shay J. W., Werbin H. Are mitochondrial DNA mutations involved in the carcinogenic process? Mutat Res. 1987 Sep;186(2):149–160. doi: 10.1016/0165-1110(87)90028-5. [DOI] [PubMed] [Google Scholar]
- Singer B., Brent T. P. Human lymphoblasts contain DNA glycosylase activity excising N-3 and N-7 methyl and ethyl purines but not O6-alkylguanines or 1-alkyladenines. Proc Natl Acad Sci U S A. 1981 Feb;78(2):856–860. doi: 10.1073/pnas.78.2.856. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Singer B. The chemical effects of nucleic acid alkylation and their relation to mutagenesis and carcinogenesis. Prog Nucleic Acid Res Mol Biol. 1975;15(0):219–284. [PubMed] [Google Scholar]
- Watson W. P. Post-radiolabelling for detecting DNA damage. Mutagenesis. 1987 Sep;2(5):319–331. doi: 10.1093/mutage/2.5.319. [DOI] [PubMed] [Google Scholar]
- Wilson V. L., Smith R. A., Ma S., Cutler R. G. Genomic 5-methyldeoxycytidine decreases with age. J Biol Chem. 1987 Jul 25;262(21):9948–9951. [PubMed] [Google Scholar]
- Wunderlich V., Schütt M., Böttger M., Graffi A. Preferential alkylation of mitochondrial deoxyribonucleic acid by N-methyl-N-nitrosourea. Biochem J. 1970 Jun;118(1):99–109. doi: 10.1042/bj1180099. [DOI] [PMC free article] [PubMed] [Google Scholar]