ALTERED EXPRESSION OF GANGLIOSIDE PHENOTYPES OF HUMAN GLIOMAS IN-VIVOAND IN-VITRO

A library of epitope-defined antiganglioside monoclonal antibodies has been used to analyze the ganglioside phenotype of human glioma cell l ines, rodent xenografts derived from them, and a separate panel of hum an glioma biopsies by multiple quantitative and qualitative assays. We have shown that the ganglioside phenotypes of cultured cell lines dif fer from the ganglioside phenotypes in the xenografts grown from the p arent lines. The lacto series gangliosides 3'-isoLM1 and 3',6'-isoLD1 are expressed in the majority of primary human central nervous system neoplasms and xenografts derived from glioma cell lines, whereas gliom a cell lines themselves express 3'-isoLM1 and 3',6'-isoLD1 in only 2/1 5 and 0/15 cases, respectively. Examination of the ganglioside profile s of serially passaged xenografts established from the glioma cell lin e D-54 MG, which does not express the lacto series, revealed the appea rance of these gangliosides within one to two passages in vivo. The pr esence of these defined gangliosides in the majority of human gliomas and their absence in normal brain supports their application in compar tmental therapy of primary central nervous sytem tumors.