Figure 5.

FREG intravenous (i.v.) treatment inhibited melanoma lung metastases in a murine melanoma model. (a) In vitro expression of PDGF-Rα was investigated in growing B16F10 mouse melanoma cell line, by western blotting analysis. Human HUVEC cells were used as positive control, according to previously reported data.²⁶ (b) B16F10 melanoma cells (2 × 10⁵/200 µl PBS) were injected i.v. into C57BL/6 mice tail vein at day −6. Animals were treated i.v. with 50 µl of FREG (3 or 6 mg/kg/day) on days 0, 2, 4, 7, and 8. Macroscopic lung metastases are indicated in representative lungs. Bar = 1 mm. (c) Quantification of macroscopic lung metastases indicates a significant reduction upon FREG treatment. Asterisk (*) indicates statistical significance (P < 0.05 versus ctrl) according to one-way analysis of variance test followed by Dunnett's multiple comparison test. Linear trend post hoc analysis indicates a significant dose-related effect (P < 0.02). (d) Microscopic metastatic foci upon histological analysis. Representative image are reported, indicating representative foci-size. Bar = 25 µm. (e) Quantification of number of microscopic foci per slide indicates a significant reduction upon FREG treatment (P < 0.05 versus ctrl). ctrl, control; PDGF-Rα, platelet-derived growth factor-receptor-α.