Figure 2

Isobolograms of in vitro drug combinations. Isobologram analysis of the combination of gemcitabine and troxacitabine in Panc-1, MIA PaCa-2, AsPc-1 and Capan-2 cells. The individual doses of gemcitabine and troxacitabine to achieve 90% (straight line) growth inhibition (Fa = 0.90), 75% (hyphenated line) growth inhibition (Fa = 0.75), and 50% (dotted line) growth inhibition (Fa = 0.50) were plotted on the x- and y-axes. Combination index (CI) values calculated using Calcusyn software is represented by points above (indicate antagonism between drugs) or below the lines (indicate synergy). (X symbol) ED_50, (plus sign) ED₇₅ and (open dotted circle ) ED₉₀.