Dose response of CB7, A64, and A70 for mafosfamide sensitization. (A) A549 and SF767 were treated with MF (ED50 concentration) with increasing concentration of analogues CB7, A64, and A70. The p-values were calculated by comparing the cellular proliferation of DMSO treated cells versus inhibitor treated cells (∗, p < 0.05, n = 15) or MF treated cells versus MF + ALDH3A1 inhibitor treated cells (∗∗, p < 0.005, n = 15). Black bars represent ALDH3A1 inhibitor treatment alone, and gray bars represent ALDH3A1 inhibitor plus MF treatment, mean value ± SE. (B) SF767 cells were treated with CB7, A64, and A70 at 10 μM with increasing concentration of MF. Cell proliferation was determined using MTT assay, and plot for percent (%) proliferation was created using the SigmaPlot (version 11, StatSys). Shaded circles (●) show SF767 cell proliferation treated with mafosfamide in the absence of inhibitors. Open circles (○), inverted shaded triangles (▼), and open triangles (△) show cell proliferation with MF in the presence of inhibitors CB7, A64, and A70, respectively. The solid trend lines (MF + DMSO (black), MF + CB7 (pink), MF + A64 (green), MF + A70 (blue)) represent the fits to the three-parameter logistics equation. DMSO concentration was limited to 0.25% (v/v) (n = 15). Figures were generated using SigmaPlot, version 11.0.