Gangliosides of human cerebral astrocytomas

Ganglioside content and composition were examined in a series of 25 human gliomas, which were graded histologically by the criteria of Kernohan. The concentration of total gangliosides (lipid-bound sialic acid [LBSA]) was decreased with respect to normal brain tissue in nearly all tumors, and the extent of reduction correlated with the stage of tumor anaplasia. The distribution of individual gangliosides was altered in glial tumor tissue with an increase in proportion of the structurally simple gangliosides and reduction of polysialogangliosides. The most consistent and significant difference was the elevation of proportion of ganglioside GD3 from 4-5% of total LBSA in normal brain to 20% in the astrocytoma grade IV. The proportions of gangliosides GM2 and GD2 were also found to be elevated in all grades of the tumors. The simplification of ganglioside composition seems to be associated with transformation of the astrocyte with the accumulation of the simpler gangliosides, since the changes resemble those reported with in vitro transformation rather than those of analyses of preparations of purified glial cells.