The antineoplastic effect of Corynebacterium parvum modified by lysozyme treatment

The study was conducted to evaluate the possibility that host factors may modulate the antitumor effect of C. parvum (CP). Heat-killed CP after being subjected to limited digestion by lysozyme (L-CP) produced a superior effect on the inhibition of local growth of murine mammary carcinoma (CD₈F₁) comparsed to unmodified CP. The median survival time (MST) of tumor-bearing animals that were treated with L-CP was slightly but not significantly increased over that of the immunotherapeutic response to unmodified CP. This modified CP was capable of reducing the incidence of early death in tumor-bearing animals. The modified CP was also more toxic than the unmodified. In contrast, mixed glycosidase had no effect on the antitumor potency of CP. The usefulness of enzymatic modification of whole CP in improving the tumor-therapeutic potency of CP is discussed.