Figure 5.

Pantoprazole enhances the anticancer effect of vitamin C in mice bearing subcutaneous PC3 xenografts. (A) BALB/c nude mice (n=24; 4-6-week-old males) were subcutaneously injected with 5×10⁶ PC3 cells. When the tumor size had reached 100 mm³, pantoprazole (PPI, 200 mg/kg, daily) and vitamin C (VC, 4 g/kg, twice daily) were injected intraperitoneally into the mice. After 15 days, all mice were euthanized, the remaining tumors were removed, and their volumes were measured. In the combined treatment group (VC + PPI), pantoprazole was given one day before injection of vitamin C. Left: tumor growth curves (day 0 – day 15) after the respective treatments; right: tumors prepared from the six different mice from each treatment group (control, PPI, VC, VC + PPI) after sacrifice (day 15). (B) Immunohistochemical (IHC) analysis of the proliferation marker Ki67 and the apoptosis marker cleaved caspase-3 in explanted tumors (upper panel). The grey bar in the upper left corner of each picture represents 100 µm. The lower panel shows semiquantitative analysis of the IHC results using H-scores as described in the Methods section. Quantification of the IHC results demonstrated a significant decrease (p = 0.004) in expression of the proliferation marker Ki67 and a significant increase (p < 0.0001) in expression of the apoptosis marker cleaved caspase 3 in VC + PPI-treated cells compared to controls, respectively. The bars represent the mean and SD of the mean of n≥3.