Immunotherapeutic use of neuraminidase in chemically induced carcinogenesis

The action of neuraminidase fromVibriocholerae on the development of sarcomas induced in CBA mice by dimethylbenzanthracene was studied. Administration of the enzyme preparation began after the appearance of tumors in the animals. Administration of 50 units neuraminidase twice a week to the mice for 3 months was effective in the early stages of carcinogenesis. An increase in the survival period of the experimental mice compared with the control animals was observed after intraperitoneal injection of cells of a syngeneic induced sarcoma, and of injection of sensitized lymphocytes obtained from syngeneic mice with tumors into the region of the developing tumor. No positive effect was observed if lymphocytes injected into the region of the tumor were treated previously with neuraminidase. Simultaneous injection of neuraminidase into the region of the developing tumor and intraperitoneal injection of syngeneic induced sarcoma cells treated with the enzyme was particularly effective against carcinogenesis. The possibilities of the use of the enzyme neuraminidase under clinical conditions are discussed.