A newly established megakaryoblastic/erythroid cell line that differentiates to red cells in the presence of erythropoietin and produces platelet‐like particles

In August, 1992, we established a leukemic cell line (NS‐Meg) from a patient in megakaryoblastic transformation of Philadelphia chromosome‐positive chronic myeloid leukemia. The NS‐Meg cells were positive for α‐naphthyl acetate esterase and periodic acid‐Schiff (PAS) staining and for surface CD4, CD7, CD13, CD34, CD41a, and glycophorin A antigens. Ultrastructurally, the cells had α‐granules, demarcation membranes, and platelet peroxidase activity. The NS‐Meg cells spontaneously produced platelet‐like particles which contained α‐granules, mitochondria and dense bodles, strongly suggesting platelet production. Erythropoietin (Epo), granulocyte/macrophage colony stimulating factor(GM‐CSF), and interleukin 3 (IL‐3) promoted the growth of NS‐Meg cells. Phorbol‐12‐myristate‐13‐acetate increased the expression of both CD41a and CD61 antigens. Ten‐day exposure to Epo induced mature erythroblasts and red cells. These benzidine‐positive cells were positive for hemoglobin F staining. Untreated NS‐Meg cells expressed mRNA for the Epo receptor (EpoR), for GATA‐1, and for α₁, α₂ and γ globin genes. These results indicate that NS‐Meg cells undergo terminal differentiation of both megakaryocyte and erythroid lineages. This cell line should be a very useful tool for the investigation of both megakaryocytic and erythroid maturation.