Isolation and characterization of glycosphingolipids from human leukocytes. A unique glycosphingolipid pattern in a case of acute myelomonoblastic leukemia

Glycosphingolipid patterns in human promyelocytic HL-60 leukemia cells susceptible or resistant to differentiation induction by phorbol 12-myristate 13-acetate

The patterns of glycosphingolipids (GSLs) were analyzed in an HL-60 cell variant, HL-205, which is susceptible to phorbol 12-myristate 13-acetate (PMA)-induced monocyte/macrophage differentiation, and in an HL-60 cell variant, HL-525, which is resistant to such differentiation. The amounts and types of the GSLs were similar in both the HL-205 and HL-525 cells and they resemble those of granulocytes. Treatment with 3 nM PMA caused the susceptible HL-205 cells (but not the resistant cells) to acquire a new GSL pattern which resembles that of monocytes. This new pattern was characterized by increases in the level of a neutral GSL, Gb3Cer, from trace levels to 0.05 mg/10(9) cells and of an acidic GSL, GM3 ganglioside, from 0.03 to 0.33 mg/10(9) cells. The increases in the level of this ganglioside were found to be due to an increase in CMP-N-acetylneuraminic acid:lactosylceramide sialyltransferase activity. These results indicate an association between PMA-induced terminal differentiation along the monocyte/macrophage cell lineage and PMA-evoked increases in specific GSLs, GM3 in particular, which is due to a rise in the activity of its synthetic enzyme.

Malignant cell glycoproteins and glycolipids

The cell surface is involved in cell growth and division, cell-cell interaction, communication, differentiation and migration, and other processes likely to be involved in malignant transformation and/or the metastatic spread of cancer. Although there are many alterations of glycoproteins and glycolipids on the malignant cell surface, it is unclear whether these alterations are epiphenomena or an integral part of the malignancy process. This article reviews the recent literature and some earlier studies relevant for understanding emerging concepts and trends with respect to malignant cell glycoconjugates. Emphasis is on structural alterations of the carbohydrate portions of malignant cell glycoproteins and glycolipids and on the enzymes (glycosyltransferases and glycosidases) involved in their metabolism. Practical applications derived from malignant cell glycoconjugate studies are discussed briefly with respect to the diagnosis, staging, monitoring, and treatment of malignant disease. The review concludes by indicating which research areas on malignant cell glycoconjugates are likely to be fruitful in increasing our basic understanding of, and ability to deal effectively with, malignant disease.

Use of the enzyme-linked immunoadsorbent assay to monitor the purification of glycosphingolipid antigens by high-performance liquid chromatography

An enzyme-linked immunoadsorbent assay (ELISA) technique has been applied to the analysis of glycosphingolipid fractions separated by high-performance liquid chromatography. Nanogram amounts of selected fractions were placed in microtiter wells and analyzed for glycosphingolipids carrying carbohydrate epitopes recognized by monoclonal antibodies using an avidin-biotin enzyme system (ABC reagents). A large number of fractions (more than 100) can be conveniently evaluated for the presence of glycosphingolipids recognized by one or more monoclonal antibodies in a single analysis. This method is a rapid and sensitive procedure for monitoring the purification of glycosphingolipid antigens and can be used in conjunction with immunostaining of glycosphingolipids separated by thin-layer chromatography.

A murine monoclonal IgM antibody specific for blood group P antigen (globoside)

A murine monoclonal IgM erythrocyte antibody appeared to have anti-P (anti-globoside) specificity. The antibody was a relatively weak cold agglutinin, but a strong haemolysin and its reactivity with red cells was markedly enhanced by enzyme treatment. This antibody was used to study the cell and tissue distribution of globoside. Globoside was not only detectable on red cells and erythroblasts, but also on endothelial cells and on subsets of platelets, megakaryocytes and fibroblasts. It was not detectable on granulocytes, monocytes and most peripheral blood lymphocytes. Neither was it present on erythroblast precursors (CFU-E, BFU-E), pro-erythroblasts or on the cells of the pro-erythroblastic cell lines K562 and HEL. However, K562 cells expressed globoside when induced to mature into erythroblasts by sodium butyrate. Cells of patients with various leukaemias were also tested. A significant number of positively reacting cells was frequently (six out of 18) seen in cases with a CML blast crisis (CML-BC) and rarely in AML (four out of 37 cases). In CML-BC the P-positive cells were probably erythroblasts and/or megakaryoblasts. Thus, globoside appeared to be an interesting marker in CML-BC of the erythroblastic or mixed erythroblastic-megakaryoblastic type.

Characterization of cellular lipids in doxorubicin-sensitive and -resistant P388 mouse leukemia cells

The purpose of this study was to determine whether changes in cellular lipid composition accompanied the selection of cells that are resistant to the anthracycline doxorubicin. Total cellular lipid extracts from doxorubicin-sensitive and doxorubicin-resistant P388 murine leukemia cells were prepared and separated into neutral glycosphingolipids, gangliosides, phospholipids, and neutral lipid families. No significant quantitative differences in total cholesterol, lipid-bound sialic acid, neutral hexose, and lipid-bound phosphate were found between the two cell lines. Gas-liquid chromatographic analysis of the fatty acids derived from each lipid class demonstrated that sensitive and resistant cells had essentially identical fatty acid compositions. Qualitative evaluation of the four lipid classes by high-performance thin-layer chromatography revealed only minor differences in lipid composition between the resistant and the sensitive cells. Results from this study indicate that although minor differences between the two cell lines are present, no major cellular lipid differences are evident to account for the marked differences in the cellular pharmacokinetics and cytotoxic effects of doxorubicin between doxorubicin-sensitive and doxorubicin-resistant P388 murine leukemia a cells.

Biosynthesis of glycosphingolipids by human myeloid leukemia cells

We have performed comparative studies of the neutral glycosphingolipids synthesized by three human myeloid leukemia cell lines, K562, KG1, and HL-60, which were metabolically labeled with [14C]galactose, to evaluate changes in neutral glycosphingolipid synthesis with myeloid cell differentiation. Individual neutral glycosphingolipids containing one to four sugars were purified by a combination of the following methods: diethylaminoethyl-Sephadex column chromatography, acetylation-Florisil column chromatography, and high-performance liquid chromatography using an Iatrobead column. Compounds with one sugar were analyzed by thin-layer chromatography on borate plates. This analysis showed that HL-60 cells synthesize only glucosylceramide, whereas K562 and KG1 cells synthesize predominately glucosylceramide, but also a small amount of galactosylceramide. Compounds with two to four sugars were characterized by treatment with exo- and endoglycosidases. The results showed that K562 and KG1 cells are similar to cells from patients with acute leukemia in expressing two series (globo and neolacto) of natural glycosphingolipids, whereas the HL-60 cells are similar to mature human myeloid cells in expressing only one series (neolacto). Therefore, human myeloid leukemia cells blocked at different stages of differentiation vary in their ability to synthesize neutral glycosphingolipids.

Glycosphingolipid carriers of carbohydrate antigens of human myeloid cells recognized by monoclonal antibodies

Six monoclonal antibodies with known specificities for the carbohydrate antigens i, X or Y, and seven anti-myeloid antibodies (determinants unknown) selected for their differing reaction patterns with human leucocytes were tested in chromatogram binding assays for reactions with myeloid cell glycolipids derived from normal human granulocytes and chronic myelogenous leukemia cells. Antigenicities were found exclusively on minor glycolipids which were barely or not at all detectable with orcinol-sulphuric acid stain. Among these, a neutral glycosphingolipid bound the anti-i antibody Den and chromatographed as the ceramide octasaccharide, Gal beta 1----4GlcNac beta 1----3Gal beta 1----4GlcNac beta 1----3Gal beta 1----4GlcNAc beta 1----3Gal beta 1----4Glc-Cer. Several species of neutral glycosphingolipids with six to more than ten monosaccharides were detected which carry the X antigen and others the Y antigen: Gal beta 1----4(Fuc alpha 1----3)GlcNAc and Fuc alpha 1----2Gal beta 1----4(Fuc alpha 1----3)GlcNAc, respectively. In addition, three new types of carbohydrate specificities were detected among the myeloid cell glycolipids. Two were associated with neutral glycolipids: the first, recognised by anti-myeloid antibodies VIM-1 and VIM-10, was expressed on a distinct set of glycolipids with six or more monosaccharides, and the second, recognized by VIM-8, was expressed on glycolipids with more than ten monosaccharides. The third specificity, recognised by the anti-myeloid antibody VIM-2, was expressed on slow migrating sialoglycolipids with backbone structures of the poly-N-acetyllactosamine type that are susceptible to degradation with endo-beta-galactosidase. Thus, we conclude that the i and Y antigens occur among the glycolipids of normal myeloid and chronic myelogenous leukemia cells and that a high proportion of hybridoma antibodies raised against differentiation antigens of myeloid cells are directed at carbohydrate structures.

Glycosphingolipids of the globo-series are associated with the monocytic lineage of human myeloid cells

Neutral glycosphingolipids (neutral GSLs) of the human myeloid leukemia cell lines ML-2, ML-3, HL-60 and THP-1-0 were metabolically labeled with [3H]galactose and [3H]glucosamine, and analyzed by high-performance liquid chromatography. They were compared with unlabeled neutral GSLs from purified human granulocytes and monocytes. Neutral GSLs were identified by retention times and the structures were further confirmed by degradation with specific exoglycosidases. Two neutral GSLs of the globoseries, globotetraosylceramide and globotriaosylceramide were found in monocytes and the monoblastic leukemia line THP-1-0. The leukemia-derived cell-lines, ML-3 and HL-60, representing successively earlier stages of myeloid differentiation, contained respectively less neutral GSLs of the globoseries and an increasing proportion of (neo)lacto neutral GSLs. Granulocytes and the cell line ML-2 contained almost exclusively neutral GSLs of the (neo)lacto series.

A description of human placental syncytiotrophoblast membrane glycosphingolipids

The glycosphingolipid (GSL) structure of isolated human term placental syncytiotrophoblast microvillous plasma membrane (StMPM) has been investigated by Folch solvent extraction and thin-layer chromatography. StMPM preparations were shown to contain unique hydrophilic GSL species, including two highly glycosylated (greater than 15 saccharide residues/molecule) components. This fraction consistently included four major gangliosides (sialylated GSL), as well as two highly-sialylated (greater than or equal to 4 sialic acid residues/molecule) minor gangliosides.

Gangliosides of human chronic lymphocytic leukemia and hairy cells

Gangliosides were purified from the cells of two patients with hairy cell leukemia and one patient with chronic lymphocytic leukemia. Quantification of these compounds showed that these cells contain only 5-15% of the amount of lipid-bound sialic acid (gangliosides) per cell as normal lymphocytes. Structural characterization by gas-liquid chromatography, glycosidase treatment and high-performance liquid chromatography demonstrated that the major gangliosides of these leukemia cells were of the lactosyl type. Hairy cells contained monosialyllactosylceramide (II3NeuAc-LacCer), whereas chronic lymphocytic leukemia cells contained both monosialyl and disialyl lactosylceramide [II3(NeuAc)2-LacCer]. Chronic lymphocytic leukemia cell contained lesser amounts of three other gangliosides of the neolacto or lacto series as determined by endo-beta-galactosidase treatment. None of these leukemia cells contained detectable quantities of NeuAc-LcOse3Cer, a ganglioside found in normal leukocytes.

Gangliosides of human acute leukemia cells

We characterized the gangliosides from cells of eight patients with different forms of acute leukemia (four lymphoblastic, four nonlymphoblastic) by thin-layer chromatography and high-performance liquid chromatography combined with glycosidase treatment. Our analysis indicated both quantitative and qualitative differences between the gangliosides of acute leukemia and those of normal leukocytes: 1, the absolute amount of ganglioside was decreased in the acute leukemia cells; 2, in general, acute leukemias had a more simplified ganglioside pattern in that they contained a greater proportion of the short-chain ganglioside, II3NeuAc-LacCer (GM#); 3, all of the acute leukemia cells contained reduced quantities of the ganglioside N-acetylneuraminosyl-lactotriaosylceramide, a compound previously found only in normal leukocytes; and 4, a disialylated ganglioside, II3(NeuAc)2-LacCer (GD3), which is not found in normal leukocytes, was isolated from the cells of one patient with acute nonlymphoblastic leukemia. These findings demonstrate important differences between the gangliosides of acute leukemia cells and normal leukocytes.

High-performance liquid chromatography of long-chain neutral glycosphingolipids and gangliosides

We describe a method for analyzing the perbenzoyl derivatives of both neutral glycosphingolipids and gangliosides with a single high-performance liquid chromatography system. Use of this system, combined with endo- and/or exoglycosidase treatment of glycosphingolipids, provides a sensitive method for obtaining structural information on these compounds. This system has two advantages over previously published chromatography procedures: (i) it uses a commercially available column, and (ii) this single column can be used to analyze gangliosides and their neutral glycosphingolipid products generated by neuraminidase treatment. With this method, we have studied 24 different glycosphingolipids, containing one to ten sugars and one or two sialic acid residues, and have demonstrated its usefulness in evaluating the gangliosides present in human leukocytes.