A single injection of CD34-TRAIL+ cells induces tumor necrosis. (A) NOD/SCID mice bearing subcutaneous tumor nodules 10 mm in diameter were randomly assigned to receive CD34-TRAIL+ cells, mock-transduced CD34+ cells (3 × 106 cells/mouse, intravenously), recombinant sTRAIL (500 μg/mouse, intraperitoneally), or control vehicle. Hematoxylin and eosin, TUNEL, and glycophorin A staining was performed. Objective lens, original magnification: 0.08 NA dry objective, 2×. (B) Quantification of necrotic areas by ImageJ analysis on digitally acquired tissue sections stained with TUNEL. At least 6 sections from different animals were analyzed per treatment group. The boxes extend from the 25th to the 75th percentiles, the lines indicate the median values, and the whiskers indicate the range of values. *P < .001, compared with controls. #P < .001, compared with sTRAIL. (C) Injection of anti–VCAM-1 and AMD3100 reduced tumor necrosis in mice treated with CD34-TRAIL+ cells. Necrotic areas (± SD) were quantified by ImageJ analysis. Data from 1 representative experiment are shown. #P < .001, compared with control. *P = .002, compared with CD34-TRAIL+ cells. **P = .02, compared with CD34-TRAIL+ cells. ***P = .003, compared with CD34-TRAIL+ cells.
