Fig. 3

Synergistic combination by EOB, CI, and ΔDSS method. A Excess of bliss (EOB) was determined from the growth rate of cells to find synergistic drug combination. The sum of the three low dose EOBs or three high dose EOBs was separately calculated and plotted together. Three combinations in colors exhibited positive EOB in both low and high doses of drug concentration. B Change of IC50s by combination. IC50s of two drugs (drug A and B) in combination were examined separately and a fold change (IC50db/IC50sg) of each drug in combination were plotted together. IC50db represents IC50 of one drug in combination treatment and IC50sg represents IC50 of the same drug in single treatment. C Sums of all EOBs were plotted together with Loewe’s Combination Index (CI). Two combinations in different colors exhibited EOB, bigger than 0.2, and log10(CI), less than -0.2, suggesting clear synergism. D Delta drug sensitivity score (ΔDSS) was determined from the area under the inhibition curve (AUC) of drug treatment to find synergistic drug combination. ΔDSS of the three-low doses or three-high doses were separately calculated and plotted. E Sums of all EOBs were plotted together with ΔDSS using regions of more than 10% of full inhibition. Three combinations in different colors exhibited EOB, bigger than 0.2, and ΔDSS, bigger than 0.1, suggesting clear synergism