Tumorilysin collected in diffusion chambers and restraint of foreign body tumorigenesis.

Tumorilysin was found in diffusion chambers implanted s.c. or i.p. in A/BiF/F50+, DBA/2J and C57BL/6J mice. Chambers with 0.45-micrometer pores implanted s.c. were most densely covered by a syncytium of macrophages and had the most consistently active tumorilysin, compared with smaller-pored chambers or those implanted i.p. The lysin acted on cultures of murine sarcomas induced by foreign bodies, murine and human mammary carcinoma, and human lymphoma. Lysis was demonstrable within 15 min. There was a dose-response relationship between residual cell counts in cultures and concentrations of diffusion chamber fluid between 1.5 and 12.5%. Murine fibroblasts in culture were not lysed by tumorilytic fluid. The incidence of sarcomas induced by 15-mm vinyl squares implanted s.c. in A/BiF/F50+ mice was significantly reduced at 64 weeks in each of 4 experiments by 2 or 3 injections of 0.05 ml diffusion chamber fluid within the capsule on each side at 2 to 42 weeks after implantation. Analyses of the fluid, compared with serum, for the following substances showed no correlation with tumorilysis: cathepsin D; neutral protease; complement C3 fraction; and arginase. Tumorilysin was preserved by lyophilization and was destroyed by heating to 56 degrees; it did not pass filters cutting off at m.w. 300,000.