Analysis of the Glucocorticoid Receptor in Spontaneous and Drug-induced Steroid Resistant Mutants Isolated from the Human Leukemic Cell Line CEM-C7
Abstract
The mechanism of acquisition of glucocorticoid resistance in human leukemic T-cells was investigated. To assist in the analysis of the glucocorticoid receptor (GR), polyclonal anti-GR antibodies were prepared. An antibody, AP64, was made against a synthetic peptide sequence corresponding to Cys500-Lys517 of the rat GR. AP64 reacted with the native and denatured forms of rat and human GR, preferentially interacted with the steroid-bound, activated, monomeric form of the GR, and blocked the binding of activated GR to DNA. Because the epitope for AP64 is known, the antibody defined a region of the GR that is occluded in the steroid-bound unactlvated and non-steroid-bound forms. The ability of adriamycln, bleomycin, and chlorambucil to induce mutations in the GR locus was examined using the steroid-sensitive human leukemic T cell line CEM-C7. Only bleomycin and chlorambucil were mutagenic, inducing steroid-resistance 2.5- and 5-6- fold above background, respectively. Biochemical characterization of the isolated drug-Induced steroid-resistant cells demonstrated that the majority of the cells expressed the same x* (receptorless) phenotype seen after mutagenesis with classical mutagenic agents.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 04, 1991
- Accession Number
- AD1011025
Entities
People
- Lisa A. Palmer
Organizations
- Uniformed Services University of the Health Sciences