Immunohistochemically visualized localisation of gangliosides G(lac)2 (GD(3)) and G(tri)2 (GD(2)) in cells of human intracranial tumors

Antibodies against two major gangliosides detected in human brain and brain tumors - G(lac)2 (GD(3)) and G(tri)2 (GD(2)) - were tested by immunohistoc hemistry in an unselected sample of intracranial tumors during the years 19 86 through 1991. Two groups emerged as evaluable samples, namely gliomas of different grades and meningiomas. In a pilot series, it was shown that the se gangliosides could be visualized in frozen sections of cells of gliomas and meningiomas (as well as neurinomas) and in some structures of the norma l brain. It was however not possible in frozen sections to further analyze the cellu lar or subcellular expression pattern of the mentioned components and paraf fin sections with conventional processing were: only weakly and diffusely s tained. A modified protocol therefore was created that replaced alcohol pro cessing by acetone. With this protocol, interpretable results in paraffin s ections were obtained. With this method, 133 single intracranial tumors wer e investigated as to their immunohistologically detectable ganglioside expr ession. The most consistent result was that the whole cytoplasm of gliomas was stai ned by G(tri)2 (GD(2)) and G(lac)2 (GD(3)) with high preponderance of G(tri )2 (GD(2)) expression. In all meningiomas, G(lac)2 (GD(3)) had a higher exp ression than G(tri)2. No constant pattern in the other entities emerged. By comparison with GFAP expression in gliomas and vimentin in meningiomas, th e colocalisation of gangliosides and intermediary filament proteins is supp osed.