POSSIBLE ROLE OF GLUCOCORTICOID RECEPTORS IN GLOBIN GENE-EXPRESSION IN DIFFERENTIATING FRIEND-CELLS

The expression of globin genes during the dimethyl sulfoxide-induced differentiation of T3C12 Friend erythroleukemia cells is inhibited by dexamethasone and related glucocorticoids. Dexamethasone exerts a similar effect on the accumulation of globin mRNA and Hb in differentiating GM86 Friend cells, but that these cells are less sensitive to this hormone. The higher sensitivity of T3C12 cells was correlated with the presence of 6 times as many cytoplasmic glucocorticoid receptors as in the GM86 cells. The receptors of T3C12 cells have properties in common with glucocorticoid receptors found in other tissues. These receptors may be responsible for the steroid control of the globin genes in Friend cells.