POSTTRANSCRIPTIONAL REGULATION BY INTERFERON-ALPHA OF EPSILON-GLOBIN PRODUCTION IN HUMAN ERYTHROLEUKEMIA K-562 CELLS

Treatment of human K-562 erythroleukemia cells with interferon-alpha (IFN-alpha) resulted in a six-fold increase in the production Of epsilon-globin, a component of embryonic hemoglobin, but in a two-fold or less augmentation of the production of other globin species. There was no comparable increase in the production of epsilon-globin mRNA following IFN treatment. We did, however, observe a shift in the cytoplasmic location of the epsilon-globin mRNA from the messenger ribonucleoprotein (mRNP) to the polysome fraction after IFN-alpha addition. No such shift was noted in the location of the mRNA for (A)gamma-globin, the major globin product of K-562 cells, which was always present in the polysome fraction. These results are significant with respect to the mechanisms of cellular regulation and differentiation induced by IFNs.