Alterations in glycosphingolipids of plasma membranes from Morris hepatoma 5123TC

Abstract

Neutral glycosphingolipids and gangliosides were quantified in lipid extracts from normal rat liver and Morris hepatoma 5123TC and their isolated plasma membranes to determine differences in these components in the cell surface membranes of malignant cells. Glycosphingolipids present in rat liver and hepatoma were concentrated in plasma membranes, and glycosphingolipid patterns in plasma membranes reflected those of their respective whole cells. Neutral glycospingolipids of plasma membranes from normal liver and from hepatoma consisted of ceramide mono- and dihexosides, together accounting for 83 to 86% of the total neutral glycosphingolipids and some ceramide tri- and tetrahexosides. In plasma membranes from hepatoma, the concentration of neutral glycosphingolipids was generally greater than in plasma membranes from normal liver. Gangliosides of plasma membranes from hepatoma were altered more drastically, since trisialogangliosides, present in plasma membranes from normal liver, were absent, while hematosides, monosialogangliosides, and disialogangliosides were increased an average eight-fold. These data are compatible with a concept of incomplete synthesis of trisialogangliosides in hepatoma and an accumulation precursor gangliosides.