Figure 6.

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.