Figure 5. Inhibition of ErbB1-overexpressing tumors by hPEPD-G278D.
A431 cells were inoculated subcutaneously to athymic mice; once tumor size reached 40-50 mm3, the mice were treated by vehicle or EP (0.5 mg/kg) i.p. daily. Another group of mice were also treated with EP (0.5 mg/) i.p. daily, but nine days later, while continuing EP treatment, the mice also began treatment with hPEPD-G278D (4 mg/kg) i.p. every other day. The treatment period differs among different experimental groups due to difference in tumor growth, but the mice were killed 24 h after the final treatment in each group. A. Tumor size (mean ± SEM) upon treatment with vehicle (n=8), EP only (n=8), or EP plus hPEPD-G278D (n=12). B, C. Tumor weight (mean ± SD) and image of individual tumors (scale bar: 3 cm) at 24 h following final treatment. D. Mouse body weight gain during experimental treatment (mean ± SD). E. Plasma levels of mPEPD and/or hPEPD-G278D at 24 h following final treatment (mean ± SD), measured by ELISA. F. Molecular changes induced by hPEPD-G278D in the tumors, measured by IB; each lane represents one tumor. Measurement of protein phosphorylation includes p-Y1173-ErbB1, p-Y1221/1222-ErbB2, p-S473-AKT, p-T202/Y204-ERK, and p-Y705-STAT3. ****P<0.0001.