Figure 1.

Growth inhibition of human pancreatic cancer cell lines treated with amiloride, erlotinib, and their combination were evaluated by the MTT assay. Bxpc-3, PANC-1, Aspc-1, and CFPAC-1 cells were treated with amiloride (10, 30, and 100 μmol/L), erlotinib (3, 10, and 30 μmol/L), and their combination, as described in the Materials and methods. (A) Amiloride potentiated the growth inhibition of erlotinib in a dose-dependent manner. Data are expressed as the mean±SD (n=3). Significance is indicated by ^bP<0.05, ^cP<0.01 versus groups treated with erlotinib alone. (B) Assessment of the combination of amiloride and erlotinib by isobologram analysis. Values below the line are synergistic, whereas those close to the line are additive and those above the line are antagonistic.