Experimental brain glioma: Growth arrest and destruction by a blood-group-related tetrasaccharide

A synthetic tetrasaccharide (TSI), structurally related to blood groups, inhibited the proliferation of C6 glioma cells in culture and the growth of tumors formed after intracerebral transplantation of C6 cells. TS4-treated tumors were substantially smaller than controls, as expected from TS4 cytostatic action on C6 glioma cells in culture. However, in vivo treatment also caused extensive tumor destruction. This effect appeared to be caused indirectly, either by activation of natural killer cells, cytotoxic lymphocytes, or by inhibition of tumor vascularization. Enhanced antigenicity of TS4-treated glioma may be related to the increased expression of connexin 43 observed in glioma cell cultures treated with the oligosaccharide. Because concentrations of up to 20 mg/ml of TS4 were not toxic for normal neuronal or glial cells, specific oligosaccharides such as TS4 offer the possibility of selective tumor treatment.