In vivo antitumor activity of the ephrinB2-specific scFvs on SW620 and H460 xenografts. (A) mCherry-expressing SW620 colon carcinoma cells (5 × 106) or (B) mCherry-expressing H460 lung carcinoma cells (5 × 106) were injected subcutaneously into nu/nu mice. Animals were noninvasively imaged for tumor growth at 610 nm using the IVIS Imaging System and were split into 3 groups for each experiment: control (n = 4), which received PBS injections, B11 (n = 4) and 2B1 (n = 4) groups that were injected IV with 20 mg/kg of the corresponding scFv on alternating days, starting at day 4 postimplantation. Representative dorsal images of treated and untreated mice at indicated times are shown. Quantitative assessments of the tumor photon counts of treated and untreated groups are shown in the lower panels. Error bars represent the SD; *P < .001, **P < .01. (C) Immunohistochemical staining on tumor sections from mice bearing SW620 or (D) H460 xenografts after treatment with PBS, 2B1, or B11. Blood vessel endothelial cells were stained with an anti-CD34 Ab (brown, endothelial cells; magnification, 200×) and lymphatic endothelial cells with an anti-LYVE-1 (brown, lymphatic endothelial cells; magnification, 200×). Representative photomicrographs of each experiment are shown. Quantification of the corresponding positive areas was performed with AxioVison software and plotted as percentage (mean ± SD) of the stained area relative to the total tumor area. *P < .001, **P < .01.
