MAb173 inhibits KS tumor growth in vivo. (A) Athymic mice were implanted with 2 × 106 KS-SLK cells. When tumor sizes reached approximately 200 mm3, mice were randomly assigned to treatment groups (5 per group) (day 0). Mice were then treated by intraperitoneal injection of MAb173 (10 mg/kg) or Ctrl IgG, 3 times a week for 20 days. Tumor volume was measured 3 times a week. The P value was calculated by Student t test. (B) LTC xenograft study was performed as in panel A, except that the treatment was started when the tumor sizes were approximately 100 mm3. (C) KS-SLK tumor tissues harvested at the end of the experiment were subjected to Western blot analysis with Axl antibody (rabbit monoclonal). (D) Immunostaining of KS-SLK tumors with Axl antibody (red) and Ki67 antibody (green). Images were taken with a Carl Zeiss confocal microscope (100× objective) and LSM software. (E) Just before tissue harvest, mice were infused with RCA-Lectin. Perfused vessels were localized by RCA-Lectin, and microvascular endothelial cells were localized by CD31 staining. Apoptosis was examined with TUNEL assay. Nuclei were counterstained with DAPI. Images were taken with an Olympus AX70 fluorescence microscope (20× objective) and Spot Version 2.2.2 digital imaging system.
