Effects of kallistatin gene delivery on tumor growth.

(A) Kallistatin gene delivery inhibits tumor growth. MDA-MB-231 carcinoma cells were subcutaneously implanted into athymic mice. When the tumor had reached a volume of 50 mm³ (day 0), mice received an intratumoral injection of PBS (n = 16), 10⁹pfu adenovirus carrying GFP cDNA (Ad.GFP, n = 17), or kallistatin cDNA (Ad.HKBP, n = 16). Each value represents mean ± SEM. (B) Kallistatin gene delivery inhibits tumor angiogenesis. Tumor tissues were collected at 3 weeks after gene delivery. Immunostaining with an anti–mouse CD31 monoclonal antibody demonstrated rarefication of small tumor blood vessels in kallistatin-treated tumors (Ad.HKBP) as compared with control tumors (Ad.GFP). (C) The number of CD31-stained blood vessels in 6 different microscopic fields from 3 different hot spots from each tumor section (8-11 tumors in each group) was evaluated. Each value represents mean ± SEM.