Fig. 5

Combination treatment with the inhibitors of c-Met and HO-1 decreases renal tumor growth through increased oxidative stress. 786-O cells were injected subcutaneously in nude mice. When palpable tumors appeared (approximately in 10 days), animals (n = 5 each group) were injected intra-peritoneally with combinations of XL-184 (15 mg/kg/day) and ZnPP (25 mg/kg/twice a week); animals in control group were treated with vehicle. Treatments were continued for 20 days (i.e., 30 days following tumor injection). a Changes in the mean of tumor volumes have been shown in the tumor growth curve. The data reflect representative of two independent experiments. Points, average of tumor volume; bars ± S.D. + p < 0.001 compared with vehicle-treated group, and #p < 0.001 compared with ZnPP- and XL-184-treated groups. b Tumors were harvested on completion of the experiment, and two representative tumors from each experimental group has been presented to reflect tumor sizes. c Representative photomicrographs (magnification, x400) demonstrating the immunohistochemical expression of CD31 in the tissue sections from each treatment group. Right, mean vessel density analyzed by standard grid counting of CD-31-positive vessels at x400 magnification. The data reflect three different experiments, in which three to four non-overlapping fields of each specimen were examined in a blinded manner. Columns, average of vessel counts; bars ± S.D. *p < 0.05 compared with vehicle-/XL-184-/ZnPP-treated group. d Representative photomicrographs (magnification, x400) showing the immunohistochemical expression (brown-red stain) of the oxidative stress marker 4-Hydroxynonenal (4-HNE) in the harvested tissues from each treatment groups. Right, composite score of 4-HNE calculated as described in the methods section. The data reflect three different experiments, in which three to four non-overlapping fields of each specimen were examined in blinded manner. Columns, average of composite scores; bars ± S.D. *p < 0.05 compared with vehicle-/XL-184-/ZnPP-treated group. e Tissue lysates from the excised tumors of each treatment groups were used to measure the levels of 4-HNE, γ-H2AX, cleaved caspase-3 and β-actin through Western blot. Observations are representative of three different tissues from each group