EXPERIMENTAL BRAIN GLIOMA - GROWTH ARREST AND DESTRUCTION BY A BLOOD-GROUP-RELATED TETRASACCHARIDE

A synthetic tetrasaccharide (TSI), structurally related to blood group s, inhibited the proliferation of C6 glioma cells in culture and the g rowth of tumors formed after intracerebral transplantation of C6 cells . TS4-treated tumors were substantially smaller than controls, as expe cted from TS4 cytostatic action on C6 glioma cells in culture. However , in vivo treatment also caused extensive tumor destruction. This effe ct appeared to be caused indirectly, either by activation of natural k iller cells, cytotoxic lymphocytes, or by inhibition of tumor vascular ization. Enhanced antigenicity of TS4-treated glioma may be related to the increased expression of connexin 43 observed in glioma cell cultu res treated with the oligosaccharide. Because concentrations of up to 20 mg/ml of TS4 were not toxic for normal neuronal or glial cells, spe cific oligosaccharides such as TS4 offer the possibility of selective tumor treatment.