Figure 2.

Loop formation is important for the antitumor activity of VGB3. (A) To investigate the efficacy of VGB3 peptides in vivo 13 days after transplantation of a 4T1 murine MCT into female BALB/c mice (the tumor volume ~150 mm³), the treatment groups received 0.2 mg·kg⁻¹ (once every 2 days, i.v.) of either the C-VGB3 or L-VGB3 and the control group received PBS for 20 days. Error bars denote ± SEM. n = 6; **** p < 0.0001, ns = not significant; two-way ANOVA. (B) Investigation of C-VGB3 and L-VGB3 effects on mice weight. There were no significant differences between either C-VGB3 or L-VGB3 and control groups; two-way ANOVA. (C,D) Immunohistochemical (IHC) analyses of CD31 and Ki67 for the C-VGB3-, L-VGB3- and PBS-treated tumors. For IHC staining, the sections of tumor tissues were incubated with the primary mouse monoclonal antibodies for CD31 (1:2000 (v/v)) and Ki67 (5 µg·mL⁻¹). CD31 (as an indicator of microvessel density) and Ki67 (a cellular marker of cell proliferation) significantly decreased in the C-VGB3-treated tumors compared with PBS-treated tumors. Photographs were taken at 40× magnification. Error bars denote ± SEM. n = 3; * 0.02 ≤ p ≤ 0.04, ns = not significant; one-way ANOVA.