Exogenously administered gangliosides fail to increase in vivo metastatic frequency or in vitro growth of murine neoplastic cells.

The influence of gangliosides on tumor growth and frequency of metastasis in vivo, as well as growth of neoplastic cells in vitro, was tested utilizing the mouse fibrosarcoma cell line MN4. In mice receiving intramuscular tumor transplants, injections of a ganglioside mixture twice daily did not influence the tumor volume or the number of spontaneous metastases per animal. Furthermore, in mice receiving the cells by tail vein injection, injections of a ganglioside mixture once or twice daily did not affect the number of metastatic foci in the lungs. Preincubation of neoplastic cells with the ganglioside mixture decreased the number of metastatic foci in the lungs of mice receiving the cells by tail i.v. injection. The addition of ganglioside mixture to the culture medium for up to a 48-h incubation period had no effect, independently of the cell density utilized, on either the rate of DNA synthesis or the relative numbers of neoplastic cells as compared to controls; at higher ganglioside concentrations, growth was actually reduced. These results are interpreted to indicate that gangliosides, under the present conditions, do not influence tumor growth and metastatic neoplastic capacity in vivo, and growth in vitro.