K562--a human erythroleukemic cell line.

We have studied the surface membrane properties of the human leukemic cell line K562 which previously has been reported to represent an early stage of granulocyte maturation. The surface glycoprotein pattern of the K562 cells obtained after galactose oxidase-NaB[3H]4 labelling and slab gel electrophoresis shows striking similarities with that of normal erythrocytes but is completely different from the patterns of normal and malignant cells of various stages of the myeloblast to granulocyte differentiation. Moreover, the K562 cell expressed the major red cell sialoglycoprotein, glycophorin, on its surface as shown by immunofluorescence and by immunoprecipitation from labelled membrane preparations. As glycophorin is exclusively found on erythroid cells in human bone marrow we conclude that the K562 is a human erythroleukemic line.