GANGLIOSIDES AS DIAGNOSTIC MARKERS OF HUMAN ASTROCYTOMAS AND PRIMITIVE NEUROECTODERMAL TUMORS

Background. Limitations of classification schemes for brain tumors bas ed solely on morphology have stimulated searches for molecular markers of nosologic and prognostic value. Gangliosides are logical candidate s because there are high concentrations of them in the nervous system, there is evidence of their roles in regulation of growth and differen tiation, and data from small series suggest correlations between gangl ioside composition and glioma type. Methods. Ganglioside compositions were determined for 70 primary human brain tumors: 16 low grade astroc ytomas (LG), 12 anaplastic astrocytomas (AA), 34 glioblastoma multifor mes (GBM), and 8 primitive neuroectodermal tumors (PNET). This method involved identification and quantitation of specific gangliosides usin g chemical analysis and immunoanalysis. Results. Among all tumor types , histologic grade correlated with a progressive loss of 1b gangliosid es (P < 0.0001). GQ1b was higher in LGs than in AAs (P < 0.001). Both GT1b and GD1b were higher in AAs than GBMs (P < 0.01 and 0.05, respect ively) and lower in PNETs than in GBMs (P < 0.05). GM3 was higher in P NETs than in any astrocytoma group and higher in GBMs than in either A As or LGs. There was a significant difference in the content of 3'-LM1 among all groups (P < 0.005), between AAs and GBMs (P < 0.05), and be tween low grade ordinary and juvenile pilocytic astrocyomas (P < 0.01) . The lacto-series ganglioside 3'-isoLM1 was present in all groups exc ept PNET. Conclusions. These results indicate that patterns of ganglio sides could be of considerable value in refining the classification an d diagnosis of primary human brain tumors.