Androgen, Estrogen and Progestin Binding Sites in Human Leukemic Cells

Sex steroid binding capacity was investigated in malignant cells from 32 patients with acute non-lymphoblastic leukemia (25 patients with acute myeloid leukemia, 4 with subacute leukemia, 3 with chronic myeloid leukemia in blast crisis) and 30 patients with acute lymphoblastic leukemia. Specific binding of labelled steroids was characterized either by competition assay in cytosol fraction or by whole-cell incorporation. In some cases further characterization of the receptor complex was attempted by sucrose gradient centrifugation and gel filtration column. The results show the presence of specific binding sites for dexamethasone (22/32 in non ALL and 30/30 in ALL), for estrogens (11/15 in non-ALL and 5/12 in ALL), for progestins (8/25 in non-ALL and 5/13 in ALL) for androgens when R1881 was used as ligand (8/21 in non-ALL and 5/10 in ALL patients) but only 1/13 non-ALL patients and no ALL patients when labelled 5 alpha DHT was used. These results indicate that the blast cells from patients with acute leukemia contain specific proteins binding steroids with a high affinity. Our results for dexamethasone receptors are similar to those described in the literature in ALL and non-ALL.