Targeting tumor ECs. Athymic nude mice bearing subcutaneous MCF-7 tumors were injected with either 1 × 106 transducing units intratumorally or 2 × 106 transducing units intravenously with mCD105-LV transferring luciferase (A) or GFP (B). Gene transfer was analyzed 5 days after vector injection by luciferase imaging (A) and histology (B). (A) Luciferase imaging of the whole living animal (upper panel) or in dissected tumor slices (∼2 mm in width, lower panel). (B) On the cellular level, gene transfer was visualized by immunofluorescence of explanted tumors with antibodies specific for mouse CD31 (red, lower panel), GFP (green, center panel), and merge (upper panel). Nuclei in the 9-µm cryosections were stained by DAPI (blue). Scale bar, 30 µm.
