Ganglioside profiles of metastases and of metastasizing and nonmetastasizing rat primary mammary carcinomas.

The possible relationship between ganglioside levels and ganglioside profiles in malignant tumors and the formation of metastasis was investigated by the analysis of gangliosides in metastasizing SMT-2A and nonmetastasizing MT-W9a mammary carcinomas as well as in metastases formed from SMT-2A tumors. The extracted lipid of SMT-2A tumors contained 3.3-fold more lipid-bound sialic acid than did that of MT-W9a tumors.

Possible relationship between glycosphingolipids and the formation of metastasis in certain human experimental tumors.

Two tumors, human sarcoma #1 (HS #1) and human epidermoid carcinoma #3 (HEp #3), were cultured on the chorioallantoic membrane of chick embryos. Under experimental conditions, HS #1 does not metastasize, whereas HEp #3 metastasizes extensively to chick embryo lungs and other organs. The glycosphingolipid profiles of these tumors were studied and HEp #3 wad found to contain about 2.

Glycosphingolipids of subcellular fractions from normal rat liver and Morris hepatoma 5123TC.

Neutral glycosphingolipids and gangliosides were quantified in lipid extracts from plasma membranes, mitochondria, microsomes, and nuclei isolated from normal rat liver and Morris hepatoma 5123TC. Results showed a higher content of glycosphingolipids, especially gangliosides, in hepatomas and differences in the distribution of glycosphingolipids among subcellular fractions. Differences in the glycosphingolipid composition of the hepatoma, namely, the absence of trisialogangliosides and an increase in the lower molecular weight gangliosides, reflected an altered metabolism of glycosphingolipids in this tumor.

Alterations in glycosphingolipids of plasma membranes from Morris hepatoma 5123TC.

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.