The Role of Thymidylate Synthase in the Response to Fluoropyrimidine-Folinic Acid Combinations

  • Sondra H. Berger
  • Stephen T. Davis
  • Karen W. Barbour
  • Franklin G. Berger
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 131)


A panel of human colorectal tumor cell lines has been examined to determine the role of TS in the response to fluoropyrimidine antimetabolites. Among these cell lines, the response to FdUrd does not correlate with the levels of TS. In cell lines HCT 116 and RCA, which are poorly responsive to FdUrd, structural alterations in TS have been identified. In HCT 116, two TS polypeptides are present: a common form, occurring in all the cell lines and a variant form. The variant TS polypeptide has a reduced affinity for the TS ligands, FdUMP and CH2H4PteGlu, relative to the common TS polypeptide. Clonal populations of HCT 116 that overproduce each form have been isolated. Clones that overproduce the variant polypeptide are 4-fold less responsive to TS-directed cytotoxic agents than those that overproduce the common; thus, the presence of the variant TS is associated with a reduced response to TS-directed cytotoxic agents. The response of cell line RCA to FdUrd is dependent upon the extracellular CF concentration: response increases as CF is increased. RCA contains a TS enzyme with reduced affinity for CH2H4PteGlu, relative to cell line C, which is sensitive to FdUrd at all CF concentra-tions. Both cells form high chain-length polyglutamates of CH H PteGlu at CF concentratijpns in which the response to FdUrd differs by 4-fold. In RCA, the TS structural gene is variant, relative to the other cell lines. This variation may underlie the altered enzyme affinity for CH2H4PteGlu and the sensitivity to modulation of FdUrd response by CF.


Ternary Complex Thymidylate Synthetase Ternary Complex Formation Fluorodeoxyuridine Monophosphate Chinese Hamster Lung Cell 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    J.L. Grem and P.H. Fischer, Alteration of fluorouracil metabolism in human colon cancer cells by dipyridamole with a selective increase in fluorodeoxyuridine monophosphate levels, Cancer Res. 46: 6191 (1986).PubMedGoogle Scholar
  2. 2.
    B. Ullman, M. Lee, D.W. Martin, Jr., and D.V. Santi, Cytotoxicity of 5fluoro-2’-deoxyuridine: requirement for reduced folate cofactors and antagonism by methotrexate, Proc. Natl. Acad. Sci. USA 75: 980 (1978).PubMedCrossRefGoogle Scholar
  3. 3.
    W.L. Washtien, Thymidylate synthase levels as a factor in 5-fluorodeoxyuridine and methotrexate cytotoxicity in gastrointestinal tumor cells, Mol. Pharmacol. 21: 723 (1982).PubMedGoogle Scholar
  4. 4.
    A.R. Bapat, C. Zarow, and P.V. Danenberg, Human leukemic cells resistant to 5-fluoro-2’-deoxyuridine contain a thymidylate synthetase with lower affinity for nucleotides, J. Biol. Chem. 258: 4130 (1983).PubMedGoogle Scholar
  5. 5.
    N.J. Petrelli and A. Mittelman, An analysis of chemotherapy for colorectal carcinoma, J. Surg. Oncol. 25: 201 (1984).PubMedCrossRefGoogle Scholar
  6. 6.
    M.G. Brattain, A.E. Levine, S. Chakrabarty, L.C. Yeoman, J.K.V. Willson, and B. Long, Heterogeneity of human colon carcinoma, Cancer Metas. Rev. 3: 177 (1984).CrossRefGoogle Scholar
  7. 7.
    R.G. Moran, C.P. Spears, and C. Heidelberger, Biochemical determinants of tumor sensitivity to 5-fluorouracil: ultrasensitive methods for the determination of 5-fluoro-2’-deoxyuridylate, 2’-deoxyuridylate, and thymidylate synthetase, Proc. Natl. Acad. Sci. USA 76: 1456 (1979).PubMedCrossRefGoogle Scholar
  8. 8.
    D. Ayusawa, K. Iwata, T. Seno, and H. Koyama, Conditional thymidine auxotrophic mutants of mouse FM3A cells due to thermosensitive thymidylate synthase and their prototrophic revertants, J. Biol. Chem. 256: 12005 (1981).PubMedGoogle Scholar
  9. 9.
    P.H. O’Farrell, High resolution two-dimensional electrophoresis of proteins, J. Biol. Chem. 250: 4007 (1975).PubMedGoogle Scholar
  10. 10.
    S.H. Berger, C.-H. Jenh, L.F. Johnson, and F.G. Berger, Thymidylate synthase overproduction and gene amplification in fluorodeoxyuridineresistant human cells, Mol. Pharmacol. 28: 461 (1985).PubMedGoogle Scholar
  11. 11.
    D.G. Priest, K.K. Happel, and M.T. Doig, Electrophoretic identification of poly-y-glutamate chain-lengths of 5,10-methylenetetrahydrofolate using thymidylate synthetase complexes, J. Biochem. Biophys. Meth. 3: 201 (1980).PubMedCrossRefGoogle Scholar
  12. 12.
    J.A. Lewis, J.P. Davide, and P.W. Melera, Selective amplification of polymorphic dihydrofolate reductase gene loci in Chinese hamster lung cells, Proc. Natl. Acad. Sci. USA 79: 6961 (1982).PubMedCrossRefGoogle Scholar
  13. 13.
    C.A. Allegra, B.A. Chabner, J.C. Drake, R. Lutz, D. Rodbard, and J. Jolivet, Enhanced inhibition of thymidylate synthase by methotrexate polyglutamates, J. Biol. Chem. 260: 9720 (1985).PubMedGoogle Scholar

Copyright information

© Plenum Press, New York 1988

Authors and Affiliations

  • Sondra H. Berger
    • 1
  • Stephen T. Davis
    • 1
  • Karen W. Barbour
    • 2
  • Franklin G. Berger
    • 2
  1. 1.Departments of Basic Pharmaceutical SciencesUniversity of South CarolinaColumbiaUSA
  2. 2.Departments of BiologyUniversity of South CarolinaColumbiaUSA

Personalised recommendations