Proenzyme therapy of sarcoma S-180 and melanoma B16-F10

The aim of this study was to evaluate the effectiveness of individual (inactive) proenzymes and mixtures thereof in cancer treatment and to compare this treatment with more frequently used therapy based on active proteases. Experiments focused on explanation of possible mechanisms of proenzyme action against tumours are included.Proenzyme therapy of sarcoma S-180 significantly reduced tumour growth and prolonged survival of mice. The effect of trypsinogen and chymotrypsinogen was synergistic. Proenzyme therapy of melanoma B16-F10 bearing mice reduced both tumour growth and prevalence of metastases. Active enzyme based therapy of melanoma B16-F10 was less effective. Severe combined immunodeficiency (SCID) mice bearing sarcoma S-180 did not respond to the proenzyme therapy, indicating that the effect of this therapy is dependent on fully developed acquired immunity. Measured decreased levels of TGF-β and an increased amount of alpha-2 macroglobulin in serum contributed to the elucidation of the cancer treatment mechanism.Proenzyme therapy based on administration of a mixture of trypsinogen and chymotrypsinogen is effective in cancer treatment.