Table 4

Cell growth inhibition induced by topotecan in the presence or absence of AG14361

Cell linesGI50 TP (μm)aPF50
TP aloneTP + AG14361
A27807.8 ± 1.0b2.8 ± 0.5 2.8 ± 0.3 c
CP7014.0 ± 5.46.6 ± 1.3 2.1 ± 0.5 c
Fold resistant 1.8 ± 0.7 2.4 ± 0.7 c
CP70-ch320.5 ± 0.28.5 ± 0.6 2.4 ± 0.1 c
CP70-ch221.9 ± 0.216.2 ± 2.1 1.4 ± 0.2 c
Fold resistant 1.1 ± 0.01 1.9 ± 0.2 c
  • a GI50 is the concentration of topotecan (TP) ±400 nm AG14361 required to inhibit growth by 50% after 5 days of continuous exposure.

  • b Data are mean ± SD of IC50s from three independent experiments.

  • c Significant resistance or potentiation (P < 0.05: paired Student’s t test).