The deleterious effects of the exposure of cells, tissues or animals to exogenous radiations and chemicals are ameliorated by DNA repair processes. Many repair pathways are constitutive, and some, such as the SOS system in bacteria, are inducible while others, such as the UvrABC excision system in E. coli, are both constitutive and inducible (Friedberg, 1985). The ability of bacteria to adapt to low chronic doses of N-methyl-N-nitro-N-nitro-soguanine (MNNG) so as to become resistant to the cytotoxic or mutagenic effects of a large challenge dose is an important example illustrating that low chronic exposures not only may protect against subsequent high acute ones but also that extrapolation from high acute doses to low chronic ones may grossly overestimate the biological effects of the low chronic doses (Robins and Cairns, 1979). Another example is where low doses of nitrosamines protect rats against the carcinogenic effects of a later high dose (Montesano et al., 1980; Margison, 1982). In bacteria, chronic exposure to MNNG involves adaptation along separate pathways against mutagenic and cytotoxic agents.


Excision Repair Xeroderma Pigmentosum Repair Rate Pyrimidine Dimer Skin Cancer Incidence 
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  1. Barrows, L.R. and Magee, P.N., 1982, Nonenzymatic methylation of DNA by S-adenosylmethionine in vitro, Carcinogenesis, 3:349.PubMedCrossRefGoogle Scholar
  2. Evensen, G., and Seeberg, E., 1982, Adaptation to alkylation resistance involves induction of a DNA glycosylase, Nature (London), 296:773.CrossRefGoogle Scholar
  3. Friedberg, E.C., 1985, “DNA Repair,” W.H. Freeman, New York.Google Scholar
  4. Grafstrom, R. C., Pegg, A.E., Trump, B.F., and Harris, C.C., 1984, O 6-alkylguanine-DNA alkyltransferase activity in normal human tissues and cells, Cancer Res., 44:2855.PubMedGoogle Scholar
  5. Harm, W., 1969, Biological determination of the germicidal activity of sunlight, Radiat. Res., 40:63.PubMedCrossRefGoogle Scholar
  6. Harm, W., 1980, “Biological Effects of Ultraviolet Radiation,” Cambridge Univ. Press, Cambridge.Google Scholar
  7. Kantor, G.J., and Hull, D.R., 1978, A comparison of the responses of arrested HDF populations to UV and X-rays, J. Supramol. Struct. Suppl. 2, 8:81.Google Scholar
  8. Kantor, G.J., and Hull, D.R., 1979, An effect of ultraviolet light on RNA and protein synthesis in nondividing human diploid fibroblasts, Biophys. J., 27:359.PubMedCrossRefGoogle Scholar
  9. Karran, P., Hjelmgren, T., and Lindahl, T., 1982, Induction of a DNA glycosylase for N-methylated purines is a part of the adaptive response to alkylating agents, Nature (London), 296:770.CrossRefGoogle Scholar
  10. Kidson, C., Chen, P., Imray, F.P., and Gipps, E., 1983, Nervous system disease associated with dominant cellular radiosensitivity, in: “Cellular Responses to DNA Damage,” pp. 721–729, E.C. Friedberg and B.A. Bridges, eds., A.R. Liss, New York.Google Scholar
  11. Konze-Thomas, B., Hazard, R.M., Maher, V.M., and McCormick, J.J., 1982, Extent of excision repair before DNA synthesis determines the mutagenic but not the lethal effect of UV radiation, Mutat. Res., 94:421.PubMedCrossRefGoogle Scholar
  12. Kraemer, K.H., Lee, M.Y., and Scotto, J., 1984, DNA repair protects against cutaneous and internal neoplasia: evidence from xeroderma pigmentosum, Carcinogenesis, 5:511.PubMedCrossRefGoogle Scholar
  13. Lindahl, T., 1982, DNA repair enzymes, Annu. Rev. Biochem., 51:61.PubMedCrossRefGoogle Scholar
  14. Margison, G.P., 1982, Chronic or acute administration of various dialkylnitrosamines enhances the removal of O 6-methylguanine from rat liver DNA in vivo, Chem.-Biol. Interact., 38:189.PubMedCrossRefGoogle Scholar
  15. Montesano, R., Bresil, H., Planche-Martel, G., Margison, G.P., and Pegg, A.E., 1980, Effect of chronic treatment of rats with dimethylnitrosamine on the removal of O 6-methylguanine from DNA, Cancer Res., 40:452.PubMedGoogle Scholar
  16. Myrnes, B., Giercksky, K.E., and Krokan, H., 1983, Interindividual variation in the activity of O 6-methylguanine-DNA methy1-transferase and uracil-DNA glycosylase in human organs, Carcinogenesis, 4:1565.PubMedCrossRefGoogle Scholar
  17. Painter, R.B., 1981, Radioresistant DNA synthesis: an intrinsic feature of ataxia telangiectasia. Mutat. Res., 84:183.PubMedCrossRefGoogle Scholar
  18. Pegg, A.E., 1984a, Methylation of the O 6 position of guanine in DNA is the most likely event in carcinogenesis by methylating agents, Cancer Invest., 2:223.PubMedCrossRefGoogle Scholar
  19. Pegg, A.E., 1984b, Repair of O 6-methylguanine in DNA by mammalian tissues, in: “Biochemical Basis of Chemical Carcinogenesis,” pp. 265–274, H. Greim, R. Jung, M. Kramer, M. Marquardt, and F. Oesch, eds., Raven Press, New York.Google Scholar
  20. Robbins, J.H., 1983, Hypersensitivity to DNA-damaging agents in primary degenerations of excitable tissue, in: “Cellular Responses to DNA Damage,” pp. 671–700, E.C. Friedberg and B.A. Bridges, eds., A.R. Liss, New York.Google Scholar
  21. Robins, P., and Cairns, J., 1979, Quantitation of the adaptive response to alkylating agents, Nature (London), 280:74.CrossRefGoogle Scholar
  22. Scotto, J., Fears, T.R., and Fraumeni, J.F., Jr., 1983, “Incidence of Nonmelanoma Skin Cancer in the United States,” DHHS Pub. No. (NIH) 76–1029, Bethesda, MD.Google Scholar
  23. Setlow, R.B., 1982, DNA repair, aging, and cancer, Natl. Cancer Inst. Monogr., 60:249.PubMedGoogle Scholar
  24. Setlow, R.B., 1983, Variations in DNA repair among humans, in: “Human Carcinogenesis,” pp. 231–254, C.C. Harris and H.N. Autrup, eds., Academic Press, New York.Google Scholar
  25. Setlow, R.B., and Setlow, J.K., 1972, Effects of radiation on polynucleotides, Annu. Rev. Biophys. Bioengineer., 1:293.CrossRefGoogle Scholar
  26. Shapiro, R., 1981, DNA damage caused by hydrolysis, in: “Chromosome Damage and Repair,” pp. 3–18, E. Seeberg and K. Kleppe, eds., Plenum Academic, New York.CrossRefGoogle Scholar
  27. Shore, R.E., Albert, R.E., Reed, M., Harley, N., and Pasternack, B.S., 1984, Skin cancer incidence among children irradiated for ringworm of the scalp, Radiat. Res., 100:192.PubMedCrossRefGoogle Scholar
  28. Singer, B., 1984, Alkylation of the O 6 of guanine is only one of many chemical events that initiate carcinogenesis, Cancer Invest., 2:233.PubMedCrossRefGoogle Scholar
  29. Stern, R.S., Zierler, S., and Parrish, J.A., 1982, Psoriasis and the risk of cancer, J. Invest. Dermatol., 78:147.PubMedCrossRefGoogle Scholar
  30. Waldstein, E.A., Cao, E.-H., Bender, M.A., and Setlow, R.B., 1982a, Abilities of extracts of human lymphocytes to remove O 6-methylguanine from DNA, Mutat. Res., 95:405.PubMedCrossRefGoogle Scholar
  31. Waldstein, E.A., Cao, E.-H., Miller, M.E., Cronkite, E.P., and Setlow, R.B., 1982b, Extracts of chronic lymphocytic leukemia lymphocytes have a high level of DNA repair activity for O 6-methylguanine, Proc. Natl. Acad. Sci. USA, 79:4786.PubMedCrossRefGoogle Scholar
  32. Wiestler, O., Kleihues, P., and Pegg, A.E., 1984, O 6-alkylguanine-DNA alkyltransferase activity in human brain and brain tumors, Carcinogenesis, 5:121.PubMedCrossRefGoogle Scholar
  33. Yarosh, D.B., Foote, R.S., Mitra, S., and Day, R.S., III., 1983, Repair of O 6-methylguanine in DNA by demethylation is lacking in Mer- human tumor cell strains, Carcinogenesis, 4:199.PubMedCrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1985

Authors and Affiliations

  • R. B. Setlow
    • 1
  1. 1.Biology DepartmentBrookhaven National LaboratoryUptonUSA

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