Glycosphingolipids of K562 cells: A chemical and immunological analysis

Abstract

The K562 cell line, which was established from a patient with chronic myeloid leukemia in blast crisis, was thought to be myeloid, but recent data indicate that it is an undifferentiated erythroid cell line. We have found that the glycosphingolipid content of these cells differs considerably from that of mature erythrocytes. Globotetraosylceramide, the most abundant glycolipid of mature red cells, was not detected in K562 cells, and neither was globotriaosylceramide. The predominant neutral glycolipids of K562 cells are monohexaosylceramides, which are a mixture of glucosyl- and galactosylceramides, and lactotriaosyl- and lactoneotetraosylceramides were also detected. Secondly, gangliosides which contain N-acetylgalactosamine were much more abundant than those containing N-acetylglucosamine in K562 cells, in contrast to erythrocytes. The most abundant ganglioside of K562 cells, GM2, is present in trace quantities in erythrocytes. A third major difference between these two cells lies in their relative proportions of neutral glycolipids and gangliosides. The molar ratio of neutral glycolipids/gangliosides is approximately 15:1 in erythrocytes and 1:1 in K562 cells. These striking differences between K562 cells and mature erythrocytes indicate that glycolipids may be useful cell surface markers of normal erythrocyte differentiation, and of erythroleukemias.

3′-Azidothymidine (Zidovudine) Inhibits Glycosylation and Dramatically Alters Glycosphingolipid Synthesis in Whole Cells at Clinically Relevant Concentrations

“…1); sphingolipids were identified by comigration with standards under three solvent conditions as described in Table II. The major acidic glycosphingolipids were GD1a, SPG, GM2, and GM3, while the primary neutral glycosphingolipids were lactosylceramide and glucosylceramide, a composition in agreement with that previously reported for K562 cells (18,27). Fig.…”

Evaluation of glycoconjugates on the K562 cell surface by means of lectin binding — comparison with human erythrocytes

“…The high-affinity receptors for peanut agglutinin in desialylated 1(562 cells may be Galfll-3GalNAc-chains of glycophorin A and glycolipids terminated with this sequence. However, despite the relatively high content of gangliosides (including GM1 in K562 cells [8,11], their amount is too low [11] to account together with glycophorin for the extensive binding of peanut agglutinin. Most probably K562 cells contain a large amount of other glycoprotein(s) with sialylated Galfll-3GalNAc-chains.…”

“…K562 cells contain some surface components identical or similar to those present on erythrocyte membranes, including glycophorin A [3,4], erythroglycan-type oligosaccharide chains [5], fetal antigen i [6][7][8], and the I antigen which is expressed on a minor cell fraction [7,8]. On the other hand, K562 cells do not express blood group ABH antigens [8][9][10] and show different patterns of glycolipids [8,11[, surface glycoproteins [3] and smaller size N-glycosidic oligosaccharide chains [12] compared to erythrocytes. Moreover, some platelet glycoproteins were immunologically detected on K562 cells [13].…”

My career as an immunoglycobiologist

“…The most abundant neutral GSLs are glucosyl and galactosyl ceramides, and globoside, the most abundant GSL of mature erythrocytes, was not detected. 45) Gangliosides containing N-acetylgalactosamine were more abundant than those containing N-acetylglucosamine. The molar ratio of neutral GSLs/gangliosides was 1 : 1 in K562 cells, compared to 15 : 1 in mature erythrocytes.…”