Tumors of treated mice show reduced tumor size and increased apoptosis.

The top 4 panels are photomicrographs of hematoxylin and eosin–stained sections of PC-3 orthotopic tumors. Top and center left panels show that control mice treated with the diluent alone (PBS) reveal a large tumor (indicated by asterisk) encircled by immune cells (arrows) noted by dense nuclear stain (at lower power) and a high mitotic rate in the tumor at higher power. Top and center right panels show that VEGF AS-3–treated mice reveal a small tumor nodule within the prostate gland (arrow), showing infiltration with immune cells at higher power. Data representative of TUNEL staining for apoptosis in mice bearing human ovarian tumor are shown in the lower two panels. Mice treated with AS-3m show increased apoptosis in the cells lining the vascular structures and the tumor tissue (right panel). Mice receiving the diluent show substantially fewer apoptotic cells (left panel). Apoptotic cells stain red and are indicated by arrows; arrowheads indicate a tumor vessel. The scale bar represents 70 μm.