Enhancement of the incorporation of 5-fluorodeoxyuridylate into DNA of HL-60 cells by metabolic modulations.
The exposure of HL-60 human promyelocytic leukemia cells to 0.5 microM 5-fluoro-2'-[3H]deoxyuridine (FdUrd) for 16 hr resulted in the incorporation of 5.14 +/- 0.31 (S.D.) X 10(-7) mol FdUrd into DNA per mol of DNA nucleotide, which corresponds to 0.146 +/- 0.082 pmol FdUrd per 10(7) cells. Pretreatment with 50 microM deoxythymidine for 24 hr led to a 2.7-fold increase in the incorporation of this analogue into newly synthesized DNA during the ensuing 16-hr exposure to 0.5 microM [3H]FdUrd. Pretreatment with 0.5 microM methotrexate for 3 hr also increased the [3H]FdUrd incorporation into newly synthesized DNA approximately 5-fold. The coexistence of deoxythymidine or methotrexate with [3H]FdUrd, however, led to decreased incorporation of FdUrd into DNA. More than 50% of the radioactivity in DNA separated by Cs2SO4 equilibrium density gradient centrifugation was proven to be fluorodeoxyuridylate by means of its binding to Lactobacillus casei deoxythymidine monophosphate synthetase.
D002460:Cell Line; D004261:DNA Replication / Q000187:drug effects; D004273:DNA, Neoplasm / Q000302:isolation & purification; D003856:Deoxyuracil Nucleotides / Q000378:metabolism*; D005467:Floxuridine / Q000378:metabolism*; D005468:Fluorodeoxyuridylate / Q000378:metabolism*; D005472:Fluorouracil / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism*; D008727:Methotrexate / Q000494:pharmacology; D013936:Thymidine / Q000378:metabolism; D014316:Tritium
D004273:DNA, Neoplasm; D003856:Deoxyuracil Nucleotides; D005467:Floxuridine; D014316:Tritium; D005468:Fluorodeoxyuridylate; D005472:Fluorouracil; D013936:Thymidine; D008727:Methotrexate