Figure 8.

Synergistic effect of the dl922-947 and cisplatin combination. (A) MSTO-211H and NCI-H28 cell viability was analyzed by SRB assay 5 days after treatment with dl922-947, both alone and in combination with cisplatin. Left: Dose—response curves for dl922-947 alone, cisplatin alone and their combination. Results represent the means and standard deviations of two independent experiments, each conducted in triplicate, and are expressed as percentages of cell viability, calculated with respect to the control cells treated with DMSO alone. Right: Isobologram analysis to assess drug synergism. Isobolograms are derived from the mean values of the dose—response experiments reported in the left, through the CompuSyn software 1.0 at an effect level of 25 and 50%. Data points on the line indicate additivity; points below the line indicate synergy; points above the line indicate antagonism. (B) The table reports the means ± s.d. of the drug combination index (CI) at 25% (CI25) and 50% (CI50) of cell killing after 5 days of treatment and the r-values. CI values below 1 indicate drug synergism.