Research resource: modulators of glucocorticoid receptor activity identified by a new high-throughput screening assay.

Paradigms and Technologies


Glucocorticoid steroids affect almost every type of tissue and thus are widely used to treat a variety of human pathological conditions. However, the severity of numerous side effects limits the frequency and duration of glucocorticoid treatments. Of the numerous approaches to control off-target responses to glucocorticoids, small molecules and pharmaceuticals offer several advantages. Here we describe a new, extended high-throughput screen in intact cells to identify small molecule modulators of dexamethasone-induced glucocorticoid receptor (GR) transcriptional activity. The novelty of this assay is that it monitors changes in both GR maximal activity (A(max)) and EC(50) (the position of the dexamethasone dose-response curve). Upon screening 1280 chemicals, 10 with the greatest changes in the absolute value of A(max) or EC(50) were selected for further examination. Qualitatively identical behaviors for 60% to 90% of the chemicals were observed in a completely different system, suggesting that other systems will be similarly affected by these chemicals. Additional analysis of the 10 chemicals in a recently described competition assay determined their kinetically defined mechanism and site of action. Some chemicals had similar mechanisms of action despite divergent effects on the level of the GR-induced product. These combined assays offer a straightforward method of identifying numerous new pharmaceuticals that can alter GR transactivation in ways that could be clinically useful.


Blackford, John A; Brimacombe, Kyle; Dougherty, Edward J; Pradhan, Madhumita; Shen, Min; Li, Zhuyin; Auld, Douglas S; Chow, Carson C; Austin, Christopher; Simons, S Stoney;


  • Cell Line
  • Dexamethasone/ adverse effects
  • Dexamethasone/ pharmacology
  • Glucocorticoids/ adverse effects
  • Glucocorticoids/ pharmacology
  • Green Fluorescent Proteins/ genetics
  • HEK293 Cells
  • High-Throughput Screening Assays/ methods
  • Humans
  • Receptors, Glucocorticoid/ genetics
  • Receptors, Glucocorticoid/ metabolism
  • Signal Transduction/ drug effects
  • Transcription, Genetic/ drug effects
  • Transcriptional Activation/ drug effects

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