Treatment of malignant tumors with vasostatin, IL-12, and vasostatin plus IL-12.

All treatments were given by means of daily (6 days per week) sc injections of either buffer alone, vasostatin (100 μg per mouse), murine IL-12 (100 ng per mouse), or vasostatin (100 μg per mouse) plus murine IL-12 (100 ng per mouse) at a site proximal to the tumor. Tumor size was estimated as the product of 2-dimensional caliper measurements. Mean tumor size is shown for each time point. Mice were killed and autopsied; tumors were removed in toto, weighed, and formalin fixed. Mean tumor weight and standard deviations are shown for each group. Gross morphology of representative tumors (hematoxylin and eosin stain) from each group is shown. CA46 Burkitt lymphoma cell line was inoculated subcutaneously into athymic mice (8 × 10⁶cells per mouse), and 5 days later, tumor treatment was initiated; there were 18 mice in the group treated with vasostatin plus IL-12; 11 mice in each of the other groups. SW620 colon carcinoma cell line was inoculated subcutaneously into athymic mice (10⁷ cells per mouse); treatment with buffer alone and vasostatin alone was started 1 day after cell injection, and IL-12 was started 1 day later. There were 11 mice in each group. OVCAR ovarian carcinoma cell line was inoculated subcutaneously into athymic mice (8 × 10⁶ cells per mouse); all treatment was started 8 hours after cell injection. There were 9 mice in the buffer-treated group, and 10 mice in each of the other groups. Buffer (●—●); vasostatin (⋄—⋄); murine IL-12 (○—○); vasostatin plus murine IL-12 (▵—▵).