The close relationship between DNA replication and the selection of differentiation lineages of human erythroleukemia cell lines K562, HEL, and TF1 into either erythroid or megakaryocytic lineages.

The selection of differentiation lineages into either erythroid or megakaryocytic series was analyzed with human erythroleukemia cell lines K562, HEL, and cytokine-dependent TF1. A tumor promoter, TPA, induced a megakaryocyte marker, glycoprotein IIb/IIIa (GP IIb/IIIa) or IIIa (GP IIIa), but suppressed erythroid differentiation. On the other hand, aphidicolin, which is a potent inhibitor of DNA replication, inhibited GP IIb/IIIa or IIIa expression, but induced the expression of erythroid phenotypes. These phenomena were observed in all erythroleukemia cell lines tested. The bromodeoxyuridine labeling experiments indicated that de novo DNA synthesis was completely suppressed by aphidicolin treatment but was well preserved in TPA-treated cells. Among these three cell lines, erythropoietin (EPO) treatment induced erythroid differentiation of TF1 cells, which was dependent on GM-CSF or IL-3. In this case, EPO functioned as the survival factor and mild stimulator for cell proliferation as well as the inducer of erythroid differentiation. However, when either GM-CSF or IL-3 was depleted from the culture medium, TF1 ceased cell growth; concomitantly, hemoglobin-positive cells appeared, which is consistent with the results obtained with aphidicolin. The incubation of K562 cells for 48 h with either TPA or aphidicolin induced the irreversible commitment of cells to megakaryocytic and erythroid lineages, respectively. Our results using three different erythroleukemia cell lines suggest that a possible linkage between the DNA replication system and the selection of a differentiation lineage is the common feature of human erythroleukemia cell lines, and that these culture systems provide a suitable model for the analysis of the signal transduction system for differentiation lineage selection.