Measurement of deoxyuridine triphosphate and thymidine triphosphate in the extracts of thymidylate Synthase-Inhibited cells using a modified DNA polymerase assay

Robert W. Horowitz, Hong yang Zhang, Edward L. Schwartz, Robert D. Ladner, Scott Wadler

Research output: Contribution to journalArticle

23 Scopus citations


New inhibitors of the enzyme thymidylate synthase (TS) are now reaching clinical application. Alteration of the dUTP: dTTP ratio may be critical to TS inhibition-induced tumor cell death. The DNA polymerase assay with modification was used to rapidly and sensitively measure dUTP, dTTP, and dUTP:dTTP ratios in cell extracts of HT29 human colon carcinoma cells treated with the specific TS inhibitor ZD1694 [N-(5-[N-(3,4-dihydro-2-methyl-4 -oxoquinazolin-6-ylmethyl)-N-methylamino]-2-thenoyl)-L-glutamic acid]. These results revealed an increase in the dUTP:dTTP ratio at 2 hr after a 2-hr exposure to ZD1694 at concentrations of 0.05 to 0.2 μM with significant normalization at 16 hr after a 2-hr exposure despite evidence of continued TS inhibition. This assay is highly sensitive and reproducible for levels of dUTP and is less labor intensive than traditional assays.

Original languageEnglish (US)
Pages (from-to)635-638
Number of pages4
JournalBiochemical Pharmacology
Issue number5
Publication statusPublished - Sep 1 1997



  • Antifolate
  • Colon cancer
  • DNA polymerase
  • Deoxynucleotides
  • Thymidylate synthase

ASJC Scopus subject areas

  • Biochemistry
  • Pharmacology

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