Table 1

Comparison of antifolate growth inhibition in wild-type HeLa cells and a derivative cell line (R3) with increased expression of thymidylate synthase

Antifolate(A) IC50 in HeLa cells (nmol/L)(B) IC50 in R3 cells (nmol/L)Fold change (B/A)
PMX19 ± 1150 ± 127.9
MTX9.7 ± 0.39.7 ± 0.31.0
ZD16942.4 ± 0.333 ± 414
ZD9331107 ± 131,470 ± 33014
AG3312,800 ± 70015,300 ± 1,5005.5
  • NOTE. Growth inhibition was determined in medium containing 2.0 μmol/L folic acid supplemented with 10% fetal bovine serum.

  • Data are the mean ± SE from three separate experiments.