Summary
5-Fluorouracil (FUra) was previously demonstrated to be incorporated into DNA at cytotoxic concentrations in mouse bone marrow cells. Subsequently, we showed that under these conditions FUra exhibited a timedependent removal from DNA accompanied by a decrease in DNA strand length. In the present study we utilized hydroxyurea to inhibit semiconservative DNA synthesis while monitoring DNA repair by measuring the incorporation of [3H]dThd into double-stranded DNA (DNAds), which can be separated from DNA at the replication fork (DNAss) by benzoylated-naphthoylated-DEAE cellulose. Under these conditions we assessed DNA repair in cells that had previously been exposed for 1 h to varying cytotoxic concentrations of FUra. The results demonstrate an increase in labelling of DNAds with increasing FUra concentrations, with no appreciable increase in incorporation of label into DNAss. In conclusion, this study demonstrates that DNA repair occurs following incorporation of FUra. The failure to repair DNA damage at higher FUra concentrations may have a role in the cytotoxicity of this drug.
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Brandt WN, Flamm WG, Bernheim MJ (1972) The value of hydroxyurea in assessing repair synthesis of DNA in HeLa cells. Chem Biol Interact 5:327
Caradonna SJ, Cheng Y-C (1980) The role of deoxyuridine triphosphate nucleotidohydrolase, uracil-DNA glycosylase, and DNA polymerase α in the metabolism of FUdR in human tumor cells. Mol Pharmacol 18:513
Cheng Y-C, Nakayama K (1983) Effects of 5-fluoro-2′-deoxyuridine on DNA metabolism in HeLa cells. Mol Pharmacol 23:171
Iyer VN, Rupp WD (1971) Usefulness of benzoylated naphthoylated DEAE-cellulose to distinguish and fractionate double-stranded DNA bearing different extents of singlestranded regions. Biochim Biophys Acta 228:117
Kufe DW, Scott P, Fram R, Major PP (1983) Biologic effect of 5-fluoro-2′-deoxyuridine incorporation in L1210 deoxyribonucleic acid. Biochem Pharmacol 32:1337
Lindahl T (1979) In: Cohn WE (ed) Progress in nucleic acid research molecular biology, vol 22. Academic Press, New York, pp 135–192
Lindahl T, Ljungquist S, Siegert N, Nyberg B, Sperens B (1977) DNA N-glycosidases: Properties of uracil-DNA glycosidase from Escherichia coli. J Biol Chem 252:3286
Lonn U, Lonn S (1983) Aphidicolin inhibits, the synthesis and joining of short DNA fragments but not the union of 10-kilobase DNA replication intermediates. Proc Natl Acad Sci USA 80:3996
Major PP, Egan E, Herrick D, Kufe DW (1982) 5-Fluorouracil incorporation in DNA of human breast carcinoma cells. Cancer Res 42:3005
Painter RB, Cleaver JE (1969) Repair replication, unscheduled DNA synthesis, and the repair of mammalian DNA. Radiat Res 37:451
Sawyer RC, Stolfi RL, Martin DS, Spiegelmann S (1984) Incorporation of 5-fluorouracil into murine bone marrow DNA in vivo. Cancer Res 44:1847
Schuetz JD, Diasio RB (1985) The effect of 5-fluorouracil on DNA chain elongation in intact bone marrow cells. Biochem Biophys Res Commun 133:361
Schuetz JD, Wallace HJ, Diasio RB (1984) 5-Fluorouracil incorporation into DNA of CF-1 mouse bone marrow cells as a possible mechanism of toxicity. Cancer Res 44:1358
Schuetz JD, Collins JM, Wallace HJ, Diasio RB (1986) Alteration of the secondary structure of newly synthesized DNA from murine bone marrow cells by 5-fluorouracil. Cancer Res 46:119
Scudiero DA, Strauss B (1974) Accumulation of single-stranded regions in DNA and the block to replication in a human cell line alkylated with methyl methane sulfonate. J Mol Biol 83:17
Scudiero D, Norin A, Karran P, Strauss B (1976), DNA excision-repair deficiency of human peripheral blood lymphocytes treated with chemical carcinogens. Cancer Res 36:1397
Tanaka M, Yoshida S, Saneyoshi M, Yamagachi T (1981) Utilization of 5-fluoro-2′-deoxyuridine triphosphate and 5-fluoro-2′-deoxycytidine triphosphate in DNA synthesis by DNA polymerase α and β from calf thymus. Cancer Res 41:4132
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This study was supported by PHS grants from the National Cancer Institute, DHHS (CA 40530 and 13148)
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Schuetz, J.D., Wallace, H.J. & Diasio, R.B. DNA repair following incorporation of 5-fluorouracil into DNA of mouse bone marrow cells. Cancer Chemother. Pharmacol. 21, 208–210 (1988). https://doi.org/10.1007/BF00262771
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DOI: https://doi.org/10.1007/BF00262771