Expression of Granulopoietic Differentiation Markers in the K562 Cell Line

Abstract

The chronic myeloid leukaemia-derived cell line K562 [5] displays, in its uninduced state, phenotypic characteristics most closely related to cells of the erythroid lineage [2]. Evidence for this comes from both biochemical and immunological analysis of its cell membrane which demonstrate the presence of molecules typical of, though sometimes subtly differing from, mature erythrocytes. Further, K562 has been shown to synthesise low levels of globin, and this is enhanced on exposure to haemin during in vitro culture. However, and in contrast, there also appears to be heterogeneity of cellular commitment in this cell line, with evidence of granulopoietic differentiation demonstrable by the use of antibodies specific for the granulocyte-monocyte cell lineage. We and others have previously shown that K562 expresses TG-1 [3], My-1 [6] and group-specific granulocyte alloantigens [1]. These findings suggested that despite a predominantly erythroid phenotype K562 has features of other haemopoietic differentiation programmes; it is not clear whether this apparent phenotypic diversity represents evidence of multipotentiality, or if expression is anomalous.

MAH is a Wellcome Trust Senior Research Fellow in Fellow in Clinical Research