Cytoplasmic glucocorticoid-binding proteins of high affinity and specificity were identified, quantified, and partially characterized in three steroid-unresponsive tissue culture lines, one derived from an AKR mouse leukemia and two derived from human lymphoblastic leukemia cells. The number of receptors per cell appeared to be comparable to that found in many steroid-responsive cells. Temperature-dependent entry of cytoplasmic receptor into the nucleus did not appear to be abnormal as determined in an in vitro nuclear binding assay. Cell growth, nucleoside and amino acid incorporation into macromolecules, amino acid pools, and glucose uptake were found to be unaffected by added glucocorticoid. The presence of specific cytoplasmic receptor proteins for glucocorticoids in malignant tissue does not appear to guarantee steroid responsiveness.

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