Two chronic myelogenous leultaemia cell lines which represent different stages of erythroid differentiation

Summary We established two cell lines, YN‐1 and Y‐1K. from the peripheral blood of two chronic myelogenous leukaemia patients in blastic crisis. Characterization of the YN‐1 and Y‐1K cells revealed that these cells expressed erythroid lineage markers. However, there was a marked difference in the level of γ‐globin mRNA and haenioglobin in YN‐1 and Y‐1K cells. YN‐1 contained approximately 1–5% benzidine‐positive staining cells, whereas no benzidine‐positive cells were observed in Y‐1K cells. Haemoglobin production in YN‐1 cells was markedly increased with various chemical inducers of erythroid differentiation, but was not in Y‐1K cells. In contrast, Y‐1K cells expressed CD34 stem cell antigen and CD41 megakaryocyte‐specific antigen. These observations suggested that, although both cell lines were committed to the erythroid lineage. each cell line represented a distinct differentiation stage in the erythroid differentiation programme. Y‐1K seemed to correspond to an early stage of cells in erythroid lineage, whereas YN‐1 represented a more advanced stage in human erythropoiesis.