These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Biochemical evidence that glucocorticoid-sensitive cell lines derived from the human leukemic cell line CCRF-CEM express a normal and a mutant glucocorticoid receptor gene.
    Author: Palmer LA, Harmon JM.
    Journal: Cancer Res; 1991 Oct 01; 51(19):5224-31. PubMed ID: 1913646.
    Abstract:
    To characterize the immunoreactive glucocorticoid receptor (GR) protein present in "receptorless" (r-) mutants isolated from the glucocorticoid-sensitive (dexs) human leukemic cell line CEM-C7, binding of [3H]dexamethasone was determined in extracts prepared from the sensitive cell line 6TG1.1 and the r- mutant ICR27TK.3 after gentle freeze-thaw lysis and low-speed centrifugation. Under these conditions there was significant high-affinity binding activity in r- extracts assayed at 4 degrees C but not at 23 degrees C. Loss of binding at 23 degrees C was not a function of GR proteolysis or denaturation of the steroid-binding site and could be prevented by the addition of sodium molybdate. Dissociation of ligand from either activated or unactivated receptors in r- extracts was significantly more rapid than from receptors in extracts prepared from normal cells, suggesting that the defect in receptors in r- cells is the result of mutation in the ligand-binding site. While the rate of dissociation from unactivated receptors in r- extracts was linear, dissociation from receptors in extracts of 6TG1.1 cells was biphasic. Analysis of these dissociation curves, as well as dissociation from receptors in the B-cell line IM-9, indicated that the mutant gene present in r- cells is also present in the dexs parental cell line. This conclusion is consistent with our previous hypothesis (J.M. Harmon et al., Mol. Endocrinol., 3:734-743, 1989) that glucocorticoid-sensitive CCRF-CEM cells express both a normal (GR+) and a mutant (GR*) allele.
    [Abstract] [Full Text] [Related] [New Search]