title: Alpha 1,4galactosyltransferase activity and Gb3Cer expression in human leukaemia/lymphoma cell lines.
abstract: 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.
authors.affiliation: Department of Chemistry/Biochemistry, San Francisco State University, CA 94132, USA.
authors.forename: C L
authors.initials: CL
authors.lastname: Stults
authors.forename: R D
authors.initials: RD
authors.lastname: Larsen
authors.forename: B A
authors.initials: BA
authors.lastname: Macher
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002454:Cell Differentiation; D002460:Cell Line; D002855:Chromatography, Thin Layer; D005434:Flow Cytometry; D005700:Galactosyltransferases / Q000378:metabolism*; D006028:Glycosphingolipids / Q000302:isolation & purification / Q000378:metabolism; D018922:HL-60 Cells; D006801:Humans; D007938:Leukemia; D008223:Lymphoma; D008969:Molecular Sequence Data; D009000:Monocytes; D014281:Trihexosylceramides / Q000096:biosynthesis*; D014407:Tumor Cells, Cultured
chemical_list: D006028:Glycosphingolipids; D014281:Trihexosylceramides; C018549:globotriaosylceramide; D005700:Galactosyltransferases; C045097:UDP-galactose-lactosylceramide alpha 1-4-galactosyltransferase