Table 2.

Cytotoxicity of etoposide, doxorubicin, and camptothecin, alone and in combination with KU59403 in LoVo and SW620 cells

SW620LoVo
% Survival% Survival
Cytotoxic drugCytotoxic aloneCytotoxic + KU59403Enhancement factoraCytotoxic aloneCytotoxic + KU59403Enhancement factor
Etoposide, 100 nmol/L89 ± 8.335 ± 12b2.9 ± 1.558 ± 8.318 ± 0.5b3.3 ± 0.4
Etoposide, 1 μmol/L3.8 ± 1.10.41 ± 0.23c12 ± 73.9 ± 0.81.1 ± 0.2c3.8 ± 1.5
Doxorubicin, 10 nmol/L50 ± 917 ± 0.2c2.9 ± 0.647 ± 3.116 ± 6.9c3.2 ± 1
Doxorubicin, 100 nmol/L0.02 ± 0.010.01 ± .0011.8 ± 0.72.1 ± 0.50.35 ± 0.04c6.1 ± 2.1
Camptothecin, 10 nmol/L2.4 ± 0.20.71 ± 0.35c4.3 ± 2.833 ± 7.96.2 ± 3. 8c6.9 ± 3.8

NOTE: Cells were exposed to etoposide or doxorubicin, at the concentrations indicated, alone or in combination with 1 μmol/L KU59403 in a final concentration of 0.5% (v/v) DMSO for 16 hours. Data, normalized in comparison with DMSO or KU59403 alone control, as appropriate, are the mean ± SD of 3 independent experiments.

  • aEnhancement factor is defined as the survival with the cytotoxic alone/survival with cytotoxic + KU59403 in each individual experiment, and data are the mean ± SD of 3 independent experiments.

  • bSignificant differences between cytotoxic drug alone versus cytotoxic + KU59404 is given by P < 0.01.

  • cSignificant differences between cytotoxic drug alone versus cytotoxic + KU59404 is given by P < 0.05.