Glucocorticoid action and novel mechanisms of steroid resistance: role of glucocorticoid receptor-interacting proteins for glucocorticoid responsiveness.

Glucocorticoids are widely used to treat inflammatory and malignant diseases. However, many individuals show a lack of therapeutic response and unwanted side-effects. Various known and unknown parameters determine glucocorticoid responsiveness, among them glucocorticoid receptor (GR)-interacting proteins. Several of the proteins interacting with GR also participate in other signal transduction pathways such as the AP-1 pathway and the nuclear factor-kappaB pathway. We suggest that a closer study of GR-interacting proteins may shed new light on mechanisms determining glucocorticoid sensitivity. In this commentary, the general mechanisms of GR action will be addressed and a proteomic-based method to study GR-interacting proteins will be described in brief.