Structure requirements and affinity of steroids to bind with receptor for induction of differentiation of cultured mouse myeloid leukemia cells.

Glucorticoid hormones induced differentiation of mouse myeloid leukemia cells. From comparison of the structure of steroids with their ability to induce phagocytic and locomotive activities, typical characters of mature macrophages and granulocytes, the simplest steroid with inducing ability was concluded to be a steroid with the structure of progesterone and one hydroxyl group at 11beta- or 21-position. The maximum induction ability seemed to require the structure of progesterone and three hydroxyl groups (at 11beta-, 17alpha-, and 21-positions). A single, 30-min pulse treatment with glucocorticoid was sufficient to induce differentiation of leukemia cells. Glucocorticoid receptors were detected in mouse myeloid leukemia cells. The binding affinity of various steroids for the cytoplasmic receptors was closely correlated with the activities of these compounds to induce differentiation of leukemia cells, suggesting that these receptors may be involved in hormonal induction of differentiation of various cells. This suggests that the binding reaction is important for differentiation of myeloid leukemia cells.