Characterization of a glucocorticoid-sensitive human lymphoid cell line

A human lymphoblastoid cell line (CEM), the growth of which is inhibited by glucocorticoids, is described. Although growth of the original uncloned cell line is only slightly retarded by dexamethasone, sensitive clones were isolated in which growth is completely blocked by 2 to 3 days of exposure to 10(-6) M dexamethasone. After 4 to 5 days, these cells become pyknotic and lyse. The inhibitory affect of dexamethasone first become apparent in suspension culture at a concentration of about 5 X 10(-8) M. Receptor analysis showed the presence of specific glucocorticoid receptors with an apparent dissociation constant for dexamethasone of about 1.3 X 10(-8) M both in the sensitive and in one resistant clone analyzed. Ability to displace dexamethasone from the receptor is correlated with the known glucocorticoid activity of all steroids tested, as is their ability to inhibit cloning of sensitive cells in agarose. These results indicate that the specificity of inhibitory effects is related to receptor specificity of inhibitory effects is related to receptor specificity. Dexamethasone is a potent inhibitor when cells are cloned in agarose, having a marked effect even at a concentration of 7 X 10(-9) M. CEM cells thus provide human cell lines suitable for in vitro analysis of steroid effects on leukemic cells.