Glycosphingolipids in human colonic adenocarcinoma.

Glycosphingolipids were analyzed from colonic tumors and histologically normal adjacent tissues, obtained at surgery from eight patients. Detailed analysis was carried out on six neutral glycolipids from normal colonic mucosa and cancerous tissues. Their structures were established by permethylation, use of glycosidases, and immunological methods. In the cancerous tissues, lactosylceramide was increased Zto B-fold and galactosylceramide was reduced. Glucosylceramide, triaosylceramide (Gala1 + aGal/ + 4GlcPl + l’ceramide), globoside (GalNAcPl + 3Gala 1 + lGalP1 + 4Glc@l + l’ceramide), paragloboside (Galfil + 4GlcNAc@l -+ 3Galfil + 4Glc/31 + l’ceramide) are present at the same levels in normal mucosa and cancerous tissue. The following five gangliosides were abundant in normal and cancerous tissue: G,,, GM,, G,,,, G,,, and a ganglioside containing lacto-N-neotetraosylceramide (NeuAccuNeuAccu2 + 3Gal/31 + 4GlcNAcfil -+ 3Galfll -+ 4Glc/31 -+ l’ceramide). All sialic acids of the gangliosides were Nacetyl derivatives. In samples obtained from five of these patients, the same amount of lipid-bound sialic acid was found in normal mucosa and cancerous tissue. Chromatographic and quantitative analysis showed no difference in gangliosides between these tissues. However, in the other three patients, ganglioside concentrations in cancerous tissue were I-fold higher than in normal mucosa. Blood group activities of glycolipid fractions obtained from normal colonic mucosa and cancerous tissue were determined by hemagglutination inhibition. There was a marked decrease or total loss of ABH blood group activity in cancerous tissue. A hexaosylceramide with Lewis* activity which appeared to be present in all tumor tissues was isolated from one tumor. This glycolipid contained fucose, galactose, Nacetylglucosamine, and glucose in molar ratios of 2:2:1:1. A pentaosylceramide containing galactose, glucose, N-acetylglucosamine, and N-acetylgalactosamine (2:l:l:l) was also isolated from this tumor. Although this glycolipid contained