Europe PMC

This website requires cookies, and the limited processing of your personal data in order to function. By using the site you are agreeing to this as outlined in our privacy notice and cookie policy.

Abstract 


O6-Alkylguanine-DNA alkyltransferase was rapidly and irreversibly inactivated by exposure to O6-benzylguanine or the p-chlorobenzyl and p-methylbenzyl analogues. This inactivation was much more rapid than with O6-methylguanine: incubation with 2.5 microM O6-benzylguanine led to more than a 90% loss of activity within 10 min, whereas 0.2 mM O6-methylguanine for 60 min was required for the same reduction. O6-Benzylguanine was highly effective in depleting the alkyltransferase activity of cultured human colon tumor (HT29) cells. Complete loss of activity was produced within 15 min after addition of O6-benzylguanine to the culture medium and a maximal effect was obtained with 5 microM. In contrast, at least 100 microM O6-methylguanine for 4 hr was needed to get a maximal effect, and this reduced the alkyltransferase by only 80%. Pretreatment of HT29 cells with 10 microM O6-benzylguanine for 2 hr led to a dramatic increase in the cytotoxicity produced by the chemotherapeutic agents 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) or 2-chloroethyl(methysulfonyl)methanesulfonate (Clomesone). Administration of O6-benzylguanine to mice at a dose of 10 mg/kg reduced alkyltransferase levels by more than 95% in both liver and kidney. These results indicate that depletion of the alkyltransferase by O6-benzylguanine may be used to investigate the role of the DNA repair protein in carcinogenesis and mutagenesis and that this treatment may be valuable to increase the chemotherapeutic effectiveness of chloroethylating agents.

Free full text 


Logo of pnasLink to Publisher's site
Proc Natl Acad Sci U S A. 1990 Jul; 87(14): 5368–5372.
PMCID: PMC54325
PMID: 2164681

Depletion of mammalian O6-alkylguanine-DNA alkyltransferase activity by O6-benzylguanine provides a means to evaluate the role of this protein in protection against carcinogenic and therapeutic alkylating agents.

Abstract

O6-Alkylguanine-DNA alkyltransferase was rapidly and irreversibly inactivated by exposure to O6-benzylguanine or the p-chlorobenzyl and p-methylbenzyl analogues. This inactivation was much more rapid than with O6-methylguanine: incubation with 2.5 microM O6-benzylguanine led to more than a 90% loss of activity within 10 min, whereas 0.2 mM O6-methylguanine for 60 min was required for the same reduction. O6-Benzylguanine was highly effective in depleting the alkyltransferase activity of cultured human colon tumor (HT29) cells. Complete loss of activity was produced within 15 min after addition of O6-benzylguanine to the culture medium and a maximal effect was obtained with 5 microM. In contrast, at least 100 microM O6-methylguanine for 4 hr was needed to get a maximal effect, and this reduced the alkyltransferase by only 80%. Pretreatment of HT29 cells with 10 microM O6-benzylguanine for 2 hr led to a dramatic increase in the cytotoxicity produced by the chemotherapeutic agents 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) or 2-chloroethyl(methysulfonyl)methanesulfonate (Clomesone). Administration of O6-benzylguanine to mice at a dose of 10 mg/kg reduced alkyltransferase levels by more than 95% in both liver and kidney. These results indicate that depletion of the alkyltransferase by O6-benzylguanine may be used to investigate the role of the DNA repair protein in carcinogenesis and mutagenesis and that this treatment may be valuable to increase the chemotherapeutic effectiveness of chloroethylating agents.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.1M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Saffhill R, Margison GP, O'Connor PJ. Mechanisms of carcinogenesis induced by alkylating agents. Biochim Biophys Acta. 1985 Dec 17;823(2):111–145. [Abstract] [Google Scholar]
  • Basu AK, Essigmann JM. Site-specifically modified oligodeoxynucleotides as probes for the structural and biological effects of DNA-damaging agents. Chem Res Toxicol. 1988 Jan-Feb;1(1):1–18. [Abstract] [Google Scholar]
  • Pegg AE. Methylation of the O6 position of guanine in DNA is the most likely initiating event in carcinogenesis by methylating agents. Cancer Invest. 1984;2(3):223–231. [Abstract] [Google Scholar]
  • Erickson LC, Bradley MO, Ducore JM, Ewig RA, Kohn KW. DNA crosslinking and cytotoxicity in normal and transformed human cells treated with antitumor nitrosoureas. Proc Natl Acad Sci U S A. 1980 Jan;77(1):467–471. [Europe PMC free article] [Abstract] [Google Scholar]
  • Brent TP. Isolation and purification of O6-alkylguanine-DNA alkyltransferase from human leukemic cells. Prevention of chloroethylnitrosourea-induced cross-links by purified enzyme. Pharmacol Ther. 1985;31(1-2):121–140. [Abstract] [Google Scholar]
  • Lindahl T, Sedgwick B, Sekiguchi M, Nakabeppu Y. Regulation and expression of the adaptive response to alkylating agents. Annu Rev Biochem. 1988;57:133–157. [Abstract] [Google Scholar]
  • Yarosh DB. The role of O6-methylguanine-DNA methyltransferase in cell survival, mutagenesis and carcinogenesis. Mutat Res. 1985 Jan-Mar;145(1-2):1–16. [Abstract] [Google Scholar]
  • Pegg AE, Dolan ME. Properties and assay of mammalian O6-alkylguanine-DNA alkyltransferase. Pharmacol Ther. 1987;34(2):167–179. [Abstract] [Google Scholar]
  • Mehta JR, Ludlum DB, Renard A, Verly WG. Repair of O6-ethylguanine in DNA by a chromatin fraction from rat liver: transfer of the ethyl group to an acceptor protein. Proc Natl Acad Sci U S A. 1981 Nov;78(11):6766–6770. [Europe PMC free article] [Abstract] [Google Scholar]
  • Pegg AE, Scicchitano D, Dolan ME. Comparison of the rates of repair of O6-alkylguanines in DNA by rat liver and bacterial O6-alkylguanine-DNA alkyltransferase. Cancer Res. 1984 Sep;44(9):3806–3811. [Abstract] [Google Scholar]
  • Morimoto K, Dolan ME, Scicchitano D, Pegg AE. Repair of O6-propylguanine and O6-butylguanine in DNA by O6-alkylguanine-DNA alkyltransferases from rat liver and E. coli. Carcinogenesis. 1985 Jul;6(7):1027–1031. [Abstract] [Google Scholar]
  • Brennand J, Margison GP. Reduction of the toxicity and mutagenicity of alkylating agents in mammalian cells harboring the Escherichia coli alkyltransferase gene. Proc Natl Acad Sci U S A. 1986 Sep;83(17):6292–6296. [Europe PMC free article] [Abstract] [Google Scholar]
  • Ishizaki K, Tsujimura T, Yawata H, Fujio C, Nakabeppu Y, Sekiguchi M, Ikenaga M. Transfer of the E. coli O6-methylguanine methyltransferase gene into repair-deficient human cells and restoration of cellular resistance to N-methyl-N'-nitro-N-nitrosoguanidine. Mutat Res. 1986 Sep;166(2):135–141. [Abstract] [Google Scholar]
  • Samson L, Derfler B, Waldstein EA. Suppression of human DNA alkylation-repair defects by Escherichia coli DNA-repair genes. Proc Natl Acad Sci U S A. 1986 Aug;83(15):5607–5610. [Europe PMC free article] [Abstract] [Google Scholar]
  • Kataoka H, Hall J, Karran P. Complementation of sensitivity to alkylating agents in Escherichia coli and Chinese hamster ovary cells by expression of a cloned bacterial DNA repair gene. EMBO J. 1986 Dec 1;5(12):3195–3200. [Europe PMC free article] [Abstract] [Google Scholar]
  • Matsukuma S, Nakatsuru Y, Nakagawa K, Utakoji T, Sugano H, Kataoka H, Sekiguchi M, Ishikawa T. Enhanced O6-methylguanine-DNA methyltransferase activity in transgenic mice containing an integrated E. coli ada repair gene. Mutat Res. 1989 Nov;218(3):197–206. [Abstract] [Google Scholar]
  • Lim IK, Dumenco LL, Yun J, Donovan C, Warman B, Gorodetzkaya N, Wagner TE, Clapp DW, Hanson RW, Gerson SL. High level, regulated expression of the chimeric P-enolpyruvate carboxykinase (GTP)-bacterial O6-alkylguanine-DNA alkyltransferase (ada) gene in transgenic mice. Cancer Res. 1990 Mar 15;50(6):1701–1708. [Abstract] [Google Scholar]
  • Brent TP, Dolan ME, Fraenkel-Conrat H, Hall J, Karran P, Laval L, Margison GP, Montesano R, Pegg AE, Potter PM, et al. Repair of O-alkylpyrimidines in mammalian cells: a present consensus. Proc Natl Acad Sci U S A. 1988 Mar;85(6):1759–1762. [Europe PMC free article] [Abstract] [Google Scholar]
  • Ding R, Ghosh K, Eastman A, Bresnick E. DNA-mediated transfer and expression of a human DNA repair gene that demethylates O6-methylguanine. Mol Cell Biol. 1985 Nov;5(11):3293–3296. [Europe PMC free article] [Abstract] [Google Scholar]
  • Barrows LR, Borchers AH, Paxton MB. Transfectant CHO cells expressing O6-alkylguanine-DNA-alkyltransferase display increased resistance to DNA damage other than O6-guanine alkylation. Carcinogenesis. 1987 Dec;8(12):1853–1859. [Abstract] [Google Scholar]
  • Dolan ME, Norbeck L, Clyde C, Hora NK, Erickson LC, Pegg AE. Expression of mammalian O6-alkylguanine-DNA alkyltransferase in a cell line sensitive to alkylating agents. Carcinogenesis. 1989 Sep;10(9):1613–1619. [Abstract] [Google Scholar]
  • Futscher BW, Micetich KC, Barnes DM, Fisher RI, Erickson LC. Inhibition of a specific DNA repair system and nitrosourea cytotoxicity in resistant human cancer cells. Cancer Commun. 1989;1(1):65–73. [Abstract] [Google Scholar]
  • Gerson SL. Modulation of human lymphocyte O6-alkylguanine-DNA alkyltransferase by streptozotocin in vivo. Cancer Res. 1989 Jun 1;49(11):3134–3138. [Abstract] [Google Scholar]
  • Karran P. Possible depletion of a DNA repair enzyme in human lymphoma cells by subversive repair. Proc Natl Acad Sci U S A. 1985 Aug;82(16):5285–5289. [Europe PMC free article] [Abstract] [Google Scholar]
  • Dolan ME, Morimoto K, Pegg AE. Reduction of O6-alkylguanine-DNA alkyltransferase activity in HeLa cells treated with O6-alkylguanines. Cancer Res. 1985 Dec;45(12 Pt 1):6413–6417. [Abstract] [Google Scholar]
  • Karran P, Williams SA. The cytotoxic and mutagenic effects of alkylating agents on human lymphoid cells are caused by different DNA lesions. Carcinogenesis. 1985 May;6(5):789–792. [Abstract] [Google Scholar]
  • Dolan ME, Young GS, Pegg AE. Effect of O6-alkylguanine pretreatment on the sensitivity of human colon tumor cells to the cytotoxic effects of chloroethylating agents. Cancer Res. 1986 Sep;46(9):4500–4504. [Abstract] [Google Scholar]
  • Yarosh DB, Hurst-Calderone S, Babich MA, Day RS., 3rd Inactivation of O6-methylguanine-DNA methyltransferase and sensitization of human tumor cells to killing by chloroethylnitrosourea by O6-methylguanine as a free base. Cancer Res. 1986 Apr;46(4 Pt 1):1663–1668. [Abstract] [Google Scholar]
  • Gerson SL, Trey JE. Modulation of nitrosourea resistance in myeloid leukemias. Blood. 1988 May;71(5):1487–1494. [Abstract] [Google Scholar]
  • Dolan ME, Pegg AE, Hora NK, Erickson LC. Effect of O6-methylguanine on DNA interstrand cross-link formation by chloroethylnitrosoureas and 2-chloroethyl(methylsulfonyl)methanesulfonate. Cancer Res. 1988 Jul 1;48(13):3603–3606. [Abstract] [Google Scholar]
  • Dolan ME, Larkin GL, English HF, Pegg AE. Depletion of O6-alkylguanine-DNA alkyltransferase activity in mammalian tissues and human tumor xenografts in nude mice by treatment with O6-methylguanine. Cancer Chemother Pharmacol. 1989;25(2):103–108. [Abstract] [Google Scholar]
  • Dexter EU, Yamashita TS, Donovan C, Gerson SL. Modulation of O6-alkylguanine-DNA alkyltransferase in rats following intravenous administration of O6-methylguanine. Cancer Res. 1989 Jul 1;49(13):3520–3524. [Abstract] [Google Scholar]
  • Pauly GT, Powers M, Pei GK, Moschel RC. Synthesis and properties of H-ras DNA sequences containing O6-substituted 2'-deoxyguanosine residues at the first, second, or both positions of codon 12. Chem Res Toxicol. 1988 Nov-Dec;1(6):391–397. [Abstract] [Google Scholar]
  • Frihart CR, Leonard NJ. Allylic rearrangement from O6 to C-8 in the guanine series. J Am Chem Soc. 1973 Oct 17;95(21):7174–7175. [Abstract] [Google Scholar]
  • BOWLES WA, SCHNEIDER FH, LEWIS LR, ROBINS RK. SYNTHESIS AND ANTITUMOR ACTIVITY OF 9-(TETRAHYDRO-2-FURYL)PURINE ANALOGS OF BIOLOGICALLY IMPORTANT DEOXYNUCLEOSIDES. J Med Chem. 1963 Sep;6:471–480. [Abstract] [Google Scholar]
  • Domoradzki J, Pegg AE, Dolan ME, Maher VM, McCormick JJ. Correlation between O6-methylguanine-DNA-methyltransferase activity and resistance of human cells to the cytotoxic and mutagenic effect of N-methyl-N'-nitro-N-nitrosoguanidine. Carcinogenesis. 1984 Dec;5(12):1641–1647. [Abstract] [Google Scholar]
  • Pegg AE, Wiest L, Foote RS, Mitra S, Perry W. Purification and properties of O6-methylguanine-DNA transmethylase from rat liver. J Biol Chem. 1983 Feb 25;258(4):2327–2333. [Abstract] [Google Scholar]
  • Bradford MM. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. [Abstract] [Google Scholar]
  • Scicchitano D, Jones RA, Kuzmich S, Gaffney B, Lasko DD, Essigmann JM, Pegg AE. Repair of oligodeoxynucleotides containing O6-methylguanine by O6-alkylguanine-DNA-alkyltransferase. Carcinogenesis. 1986 Aug;7(8):1383–1386. [Abstract] [Google Scholar]
  • Dolan ME, Scicchitano D, Pegg AE. Use of oligodeoxynucleotides containing O6-alkylguanine for the assay of O6-alkylguanine-DNA-alkyltransferase activity. Cancer Res. 1988 Mar 1;48(5):1184–1188. [Abstract] [Google Scholar]
  • Graves RJ, Li BF, Swann PF. Repair of O6-methylguanine, O6-ethylguanine, O6-isopropylguanine and O4-methylthymine in synthetic oligodeoxynucleotides by Escherichia coli ada gene O6-alkylguanine-DNA-alkyltransferase. Carcinogenesis. 1989 Apr;10(4):661–666. [Abstract] [Google Scholar]
  • Samson L, Thomale J, Rajewsky MF. Alternative pathways for the in vivo repair of O6-alkylguanine and O4-alkylthymine in Escherichia coli: the adaptive response and nucleotide excision repair. EMBO J. 1988 Jul;7(7):2261–2267. [Europe PMC free article] [Abstract] [Google Scholar]
  • Wilkinson MC, Potter PM, Cawkwell L, Georgiadis P, Patel D, Swann PF, Margison GP. Purification of the E. coli ogt gene product to homogeneity and its rate of action on O6-methylguanine, O6-ethylguanine and O4-methylthymine in dodecadeoxyribonucleotides. Nucleic Acids Res. 1989 Nov 11;17(21):8475–8484. [Europe PMC free article] [Abstract] [Google Scholar]
  • Kohn KW. Interstrand cross-linking of DNA by 1,3-bis(2-chloroethyl)-1-nitrosourea and other 1-(2-haloethyl)-1-nitrosoureas. Cancer Res. 1977 May;37(5):1450–1454. [Abstract] [Google Scholar]
  • Ewig RA, Kohn KW. DNA-protein cross-linking and DNA interstrand cross-linking by haloethylnitrosoureas in L1210 cells. Cancer Res. 1978 Oct;38(10):3197–3203. [Abstract] [Google Scholar]
  • Tong WP, Kirk MC, Ludlum DB. Formation of the cross-link 1-[N3-deoxycytidyl),2-[N1-deoxyguanosinyl]ethane in DNA treated with N,N'-bis(2-chloroethyl)-N-nitrosourea. Cancer Res. 1982 Aug;42(8):3102–3105. [Abstract] [Google Scholar]
  • Tong WP, Kirk MC, Ludlum DB. Mechanism of action of the nitrosoureas--V. Formation of O6-(2-fluoroethyl)guanine and its probable role in the crosslinking of deoxyribonucleic acid. Biochem Pharmacol. 1983 Jul 1;32(13):2011–2015. [Abstract] [Google Scholar]
  • Ludlum DB, Mehta JR, Tong WP. Prevention of 1-(3-deoxycytidyl),2-(1-deoxyguanosinyl)ethane cross-link formation in DNA by rat liver O6-alkylguanine-DNA alkyltransferase. Cancer Res. 1986 Jul;46(7):3353–3357. [Abstract] [Google Scholar]
  • Robins P, Harris AL, Goldsmith I, Lindahl T. Cross-linking of DNA induced by chloroethylnitrosourea is presented by O6-methylguanine-DNA methyltransferase. Nucleic Acids Res. 1983 Nov 25;11(22):7743–7758. [Europe PMC free article] [Abstract] [Google Scholar]
  • Brent TP, Remack JS. Formation of covalent complexes between human O6-alkylguanine-DNA alkyltransferase and BCNU-treated defined length synthetic oligodeoxynucleotides. Nucleic Acids Res. 1988 Jul 25;16(14B):6779–6788. [Europe PMC free article] [Abstract] [Google Scholar]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

Citations & impact 


Impact metrics

Jump to Citations

Citations of article over time

Alternative metrics

Altmetric item for https://www.altmetric.com/details/16831107
Altmetric
Discover the attention surrounding your research
https://www.altmetric.com/details/16831107

Article citations


Go to all (201) article citations

Funding 


Funders who supported this work.

NCI NIH HHS (3)