Changes in plasma gangliosides in relation to tumor growth and their tumor-enhancing effect.

Gangliosides in the plasma of Ehrlich ascites tumor-bearing mice showed changes, both quantitative and qualitative, with progress of tumor. Quantitative changes assessed by chemical estimation indicated a gradual increase of gangliosides up to day 6 of tumor growth followed by a decline leading to a level below the normal by day 12. Qualitative changes studied by thin-layer chromatography indicated appearance of new gangliosides in the plasma of tumor-bearing mice, which were absent from normal plasma. One of these gangliosides appears to be of tumor-cell origin. Gangliosides obtained from tumor-bearing mouse plasma enhanced tumor growth when adoptively transferred with tumor cells into normal mice.