Neutral glycosphingolipids of human acute leukemias

Sulfatides and arylsulfatase A activity in major salivary glands of hamster (Mesocricetus auratus) after adenocarcinoma induction in oral cavity

A biochemical study of sulfatides and arylsulfatase A (ASA) was carried out in the submandibular and sublingual glands of the male and female hamster Mesocricetus auratus after experimental induction of oral adenocarcinoma by 7,12-dimethylbenzanthracene (DMBA). Hamster experimental groups included control animals, animals treated with beta-carotene, animals treated with DMBA, and animals treated with DMBA plus beta-carotene. Oral cavity treatment with DMBA induced carcinogenesis in the buccal mucosa, but not in the major salivary glands, where nevertheless, the morphology and expression of both parameters examined changed. In fact, sulfatide concentrations and enzyme activity increased significantly, while in control and beta-carotene-treated hamsters they were similar in both glands and sexes. After administration of DMBA plus beta-carotene, sulfatide concentration decreased, as did ASA activity, slightly in the submandibular gland and remarkably so in the sublingual one of female hamsters. Thin-layer chromatography (TLC) analysis of lipid patterns, after DMBA treatment, revealed considerable differences, not only in sulfatides, but also in other lipid fractions, as well as between the two glands and two sexes. These findings show that oral cavity treatment with DMBA is not able to induce carcinogenesis in the major salivary glands examined; however, it does cause considerable metabolic changes.

Lipid metabolism in tumour bearing mice treated withAeromonas L-asparaginase

The anticancerous drug isolated in our laboratory from estuarineAeromonas was characterised and is found to be an enzyme, L-asparaginase. The antileukaemic effect of this drug was studied in mice by inducing leukaemia with Ehrlich ascites cell lines. It was compared with commercially available drug, Leunase, isolated fromE. coli. The lipid profiles in mice during leukaemia and under treatment was studied. The decreased levels of cholesterol and increased levels of triglycerides and phospholipids in serum, liver and kidney were observed in tumour bearing mice. Significant changes in the above values were observed with enzyme therapy. It could bring some of the values to near normal level. L-asparaginase fromAeromonas was found to be more effective.

Alpha 1,4galactosyltransferase activity and Gb3Cer expression in human leukaemia/lymphoma cell lines

We have used two methods to evaluate the level of expression of Gb3Cer in several human leukaemia/lymphoma cell lines representative of the myeloid (K562, KG-1, HL-60, and lymphoid (Reh, Daudi, Raji, RPMI 8226, CCRF-CEM, MOLT-4) lineages blocked at varied stages of differentiation. TLC immunostaining of glycolipid extracts with a monoclonal antibody, 12-101, and FACS analysis with the same antibody were used to demonstrate that the expression of Gb3Cer in neoplastic myeloid and lymphoid cells is both lineage and differentiation dependent. As a possible control point in the regulated expression of Gb3Cer we have investigated the first committed step in the synthesis of globo series glycosphingolipids that involves UDP-Gal:LacCer alpha (1,4)-galactosyltransferase (alpha 1,4GalT). We present the first characterization of this enzyme in a human myeloid cell line using an ELISA-based assay, which was subsequently used to measure alpha 1,4GalT activity in the human leukaemia/lymphoma cell lines. In general, there is a positive correlation between the levels of endogenous Gb3Cer and the level of the alpha 1,4 GalT activity. However, in two cases (KG-1 and CCRF-CEM) the level of enzyme activity did not correspond to the level of Gb3Cer expression.

Characterization of porcine kidney neutral glycosphingolipids: identification of a carbohydrate antigen recognized by human natural antibodies

We have investigated the glycosphingolipids of pig kidney with a special interest in identifying compounds which may be involved in the rejection of tissue in xenotransplantation. Nine neutral glycosphingolipids have been characterized in porcine kidney and structurally characterized by a combination of techniques including 1H-NMR, permethylation analysis and thin-layer chromatography (TLC) immunostaining with carbohydrate sequence-specific monoclonal antibodies. The major components are members of the globo family and represent the human pk and P antigens. Three other compounds were found to contain a neolacto core structure; the major neolacto compound carries a nonreducing terminal epitope (Gal alpha 1-3Gal beta 1-4GlcNAc) recognized by the naturally-occurring human antibody, anti-Gal, and a second neolacto compound carries the blood group A trisaccharide (GalNAc alpha 1-3(Fuc alpha 1-2)Gal). These results are discussed with respect to tissue transplantation.

Expression of acidic glycosphingolipids and arylsulphatase A activity in human pathological endometrium

Endometrium biopsic samples from women with cystic hyperplasia or adenocarcinoma were analysed by biochemical procedures to verify fluctuations in the acidic glycosphingolipid (sulphatide) concentration and arylsulphatase A (ASA) activity. Comparing the values of the considered parameters with those obtained in normal subjects, it was observed that ASA activity significantly increased in both pathologies; in contrast, sulphatide concentration underwent a non-significant decrease in hyperplasia and a statistically significant increase in neoplasia. The thin-layer chromatography (TLC) images revealed not only quantitative, but also qualitative differences in the lipid fractions. In fact, compared with controls, the sulphatides showed one more marked fraction in the neoplastic endometrium, and two fractions with different Rf values in the hyperplastic one. Moreover, two new unknown fractions also appeared in some subjects with cystic hyperplasia. The findings suggest the lipid metabolism undergoes considerable changes under the pathological conditions examined. The fluctuations observed, in particular, in the sulphatide concentration are believed to be related to changes in the biosynthetic and catabolic activities of the key enzymes directly involved in their metabolism, i.e. arylsulphatase A and sulphotransferase, which are regulated by sex hormones.

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.

Neutral glycosphingolipid expression in B-cell neoplasms

The expression of neutral glycosphingolipids (GSL) in 37 B-cell neoplasms [7 acute lymphocytic leukemia (ALL), 5 Burkitt's lymphoma (BL), 7 chronic lymphocytic leukemia (CLL), 5 diffuse, poorly differentiated lymphoma (DPDL), 6 diffuse histiocytic lymphoma (DHL), 3 hairy-cell leukemia (HCL), and 4 multiple myeloma (MM)] was examined. Patterns of expression of simple (GlcCer, LacCer) and globo-series GSL (Gb3, Gb4) were found for each tumor type. In addition, pre-B ALL expressed the neo-lacto series GSL, paragloboside, which was not significantly seen at later stages of maturation. As a group, leukemias expressed about 10 times higher ratios of simple GSL to Globo-series GSL as compared to lymphomas, regardless of stage of differentiation. Significant amounts of GSL of other series were not found except in one CLL which contained asialo-GM2. GSL phenotype in these cells was not grossly affected by cell genotype since pre-B ALL containing Philadelphia chromosome t(9q;22q) translocations were similar to other ALL; and DHL with t(8q;14q) translocations had GSL patterns similar to other DHL samples and dissimilar to GSL patterns found in Burkitt's lymphomas with t(8q;14q). Differences in GSL expression among the different types of B-cell neoplasm suggested that GSL patterns form a phenotypic map that may complement the traditional glycoprotein immunophenotypic map and contribute to our understanding of the biology of these diseases and B-cell differentiation.

Glycolipid changes in murine myelogenous leukemias: neutral glycolipids as markers for specific populations of leukemias

We have studied the glycolipid composition of six different murine myelogenous leukemias as well as that of T-cell leukemias and normal spleen cells. Neutral and acidic lipid fractions were isolated by column chromatography on DEAE-Sephadex and analyzed by high-performance thin-layer chromatography (HPTLC) and an HPTLC overlay method. Murine myelogenous leukemias were found to contain globo- and ganglio-series neutral glycolipids, e.g., glucosylceramide (Glc-cer), lactosylceramide (Lac-cer), globotriaosylceramide (Gb3), globoside (Gb4), Forssman glycolipid (Gb5), and asialo-GM1 (GA1). Monoblastic leukemia cells contained increased proportions of Gb3, Gb4, Gb5, and GA1. Monocytic and myelomonocytic leukemia cells contained increased proportions of Glc-cer and Lac-cer. Especially, Glc-cer accounted for approximately 60% of the total neutral glycolipids in monocytic leukemia cells. Gb3 was the major neutral glycolipid in reticulum cell neoplasm type A, and it accounted for approximately 75% of the neutral glycolipids. GA1 was the major neutral glycolipid in myeloblastic and granulocytic leukemia cells as well as T-cell leukemias. Especially, granulocytic leukemia cells contained predominantly GA1, and it accounted for approximately 80% of the total neutral glycolipids. The pattern of gangliosides in myelogenous leukemias was more complex when compared with that of the neutral glycolipids; murine myelogenous leukemias contained at least 13 gangliosides, including such major gangliosides as GM1, GM1b containing N-acetyl neuraminic acid and N-glycolyl neuraminic acid, and Ga1NAc-GM1b. Alterations of glycolipid composition in murine myeloid leukemias may be associated with cellular differentiation and maturation, and therefore these characteristic glycolipid species may be regarded as markers for specific populations of leukemia cells.

Distribution of VIM-2 and SSEA-1 glycoconjugate epitopes among human leukocytes and leukemia cells

Anti-SSEA-1 which binds to glycoconjugates with a Gal beta 1-4(fuc alpha 1-3)GlcNAc epitope and VIM-2 which binds to gangliosides with a NeuAc alpha 2-3GlcNAc beta-4(FUC alpha 1-3) GlcNAc beta 1-3Gal-epitope were used to determine the expression of their corresponding carbohydrate antigens in human leukocytes and leukemia cells. Expression of these antigens was evaluated by immunohistochemical staining of plastic embedded sections of bone marrow or isolated cells, and by immunostaining of isolated glycosphingolipids separated by thin layer chromatography. The expression of both antigens was restricted to normal and leukemic myeloid cells. A range of positive immunohistochemical staining was found among normal marrow myeloid precursors, with myeloblasts giving weaker staining than more mature cells (promyelocytes, myelocytes, metamyelocytes). A similar trend was observed with leukemia cell lines, in that the myeloblastic cell line KG1 was weakly stained compared to the partially differentiated cell line HL-60. Immunohistochemical staining of marrows from acute leukemia patients showed that the VIM-2 antigen is more strongly expressed than the SSEA-1 antigen. Interestingly, both antibodies stained AMMoL cells more intensely than AML cells. Granulocytes from marrows of chronic myelogenous leukemia (CML) patients were intensely stained by both antibodies, whereas lymphocytic leukemias (acute lymphocytic, chronic lymphocytic and hairy cell marrows) were negative. Thus, although both antigens are restricted to myeloid cells there are differences in the level of expression depending on the level of cell maturity. Immunostaining of glycosphingolipids isolated from myeloid cells demonstrated that the SSEA-1 epitope is carried by several neutral glycosphingolipids and that the VIM-2 epitope is carried by three or more gangliosides. Major SSEA-1 glycosphingolipids, with seven to more than ten monosaccharides, are expressed by all myeloid cells regardless of the level of maturity, although quantitative differences are apparent in different patient samples. Two strongly immunoreactive VIM-2 gangliosides with ten and twelve monosaccharides, respectively were found in myeloid cells. The ratio of these two gangliosides varied dramatically, with greater amounts of the more complex ganglioside being present in most cell samples. Normal neutrophils and CML cells had much greater quantities of the VIM-2 gangliosides than acute leukemia cells. This observation correlates with our earlier findings that: (1) acute leukemia cells have less total ganglioside than granulocytes and (2) acute leukemia cells have a predominance of short chain gangliosides (i.e. less than five monosaccharide units). Finally, both CML cells and normal neutrophils express a shorter chain VIM-2 ganglioside, which was not detected in acute myelogenous leukemia cells.

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.

Human hepatocellular carcinoma-associated changes of glycosphingolipids detected by two monoclonal antibodies FH2 and IB9

The changes of minor glycosphingolipids associated with human hepatocellular carcinomas were studied using monoclonal antibodies. Glycosphingolipids of twelve patients were isolated from the tumor tissues and their adjacent cirrhotic liver tissues. The immunoreactivities of glycosphingolipids with two monoclonal antibodies FH2 and IB9, that define x-structure (Gal beta 1-4[Fuc alpha 1-3]GlcNAc) and sialosyl alpha 2-6galactosyl residue, respectively, were studied by a solid phase enzyme-linked immunosorbent assay and a chromatogram immunobinding assay. X-structure was detected in the upper-phase neutral glycosphingolipids from both the cirrhotic liver tissues and the tumor tissues, but was generally expressed more strongly in the latter tissues. The thin-layer chromatography patterns of x-active glycosphingolipids were more complex in the tumor tissues. Sialosyl alpha 2-6galactosyl residue was detected in two ganglioside fractions. One ganglioside with faster migration on a thin-layer chromatogram was found in both the non-tumorous tissues and the tumor tissues. Another ganglioside with slower migration was more often detected in the tumor tissues. It was concluded that some of minor glycosphingolipids detected by monoclonal antibodies FH2 and IB9 could be the 'tumor-associated' antigens.

Analysis of chemical and biochemical properties of membrane molecules in situ by analytical flow cytometry with monoclonal antibodies

Methods are described for analysing chemical and biochemical properties of membrane antigens against which monoclonal antibodies are available. The methods are based on gentle manipulation of whole viable cells and quantitative flow cytometric fluorescence analysis of the effect of such treatment on monoclonal antibody binding. Proteolytic enzymes, glycosidases, inhibitors of biosynthesis and various mild chemical treatments have been used to derive information on the chemical nature of individual membrane antigens, their insertion in the membrane, and their turnover. The nature of the particular epitope detected by a monoclonal antibody may be probed in a similar way.

Correlation of lysosomal enzyme abnormalities in various forms of adult leukaemia

Lysosomal enzyme activities were studied in cells derived from the following types of leukaemia: chronic myeloid, acute myeloid, acute myelomonocytic, acute monocytic, non-T, non-B cell acute lymphoblastic, T-cell acute lymphoblastic, B-cell chronic lymphocytic and T-cell chronic lymphocytic. Activities of beta-hexosaminidase and alpha-mannosidase were significantly higher in cells from acute monocytic and acute myelomonocytic leukaemias, and somewhat higher in the other myeloid leukaemias, when compared with control granulocytes. Activities of beta-hexosaminidase, alpha-mannosidase, alpha-fucosidase, beta-glucuronidase and acid phosphatase were markedly lower in B cells of chronic lymphocytic leukaemia when compared with control or other leukaemic lymphoid cells. On isoelectric focusing abnormal patterns of beta-hexosaminidase, alpha-mannosidase and beta-glucuronidase activities were commonly found in myeloid and non-T, non-B cell leukaemias. All patients with acute myeloid leukaemia exhibited a relative decrease in the B form of beta-hexosaminidase activity. The results described show that studies on lysosomal enzymes may assist in the classification of different types of leukaemia.

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.