Figure 3

Sensitivity to the Combination of Cisplatin and Gemcitabine. Brca1^+/+ (a) and Brca1^-/- (b) MMECs were treated with cisplatin and gemcitabine either alone or in combination and analyzed for sensitivity by MTT assay. The IC₅₀ values determined from treatment with cisplatin and gemcitabine alone were plotted as axial points (black circles) on a Cartesian plot to generate a line of additivity. The IC₅₀ values for each combination of cisplatin and gemcitabine were then plotted as data points (black squares). Data points above the line of additivity represent an antagonistic effect, data points on the line of additivity represent an additive effect, and data points below the line additivity represent a synergistic effect. Data are representative of at least three independent experiments.