Steroid hormone receptors and the differentiation of myeloid leukemic cells.

Abstract

AbstractReceptors for the steroid hormone dexamethasone have been analyzed in clones of myeloid leukemic cells which differ in their ability to be induced by dexamethasone to form C3 and Fc rosettes, to synthesize and secrete lysozyme and form macrophages. The receptor dependent nuclear binding of (3H)‐dexamethasone has been measured in intact cells. As found with other glucocorticoid receptors, saturation of nuclear binding occurred at 4 × 10−8 M (3H)‐dexamethasone. The specificity of the receptors for only certain steroids was shown by the competition of nuclear binding by prednisolone, progesterone and testosterone, but not by the inactive steroid androstenedione. Nuclear bound hormone‐receptor complexes were released from the nucleus by treatment with deoxyribonuclease, indicating that the complexes were associated with DNA‐containing structures.The amount of nuclear binding of receptors was similar in all clones examined, including those which could not be induced for rosette, lysozyme or macrophages. The non‐responding clones were also similar to the responding clones in the kinetics of binding, hormone concentration dependence of binding and association with DNA‐containing structures. The results indicate that the non‐responding clones of myeloid leukemic cells did not have detectable defects in the number, nuclear transport, or association with DNA of their steroid receptors.