Crosstalk between estrogen receptor alpha and the aryl hydrocarbon receptor in breast cancer cells involves unidirectional activation of proteasomes |
| |
Authors: | Wormke M Stoner M Saville B Safe S |
| |
Institution: | Department of Veterinary Physiology and Pharmacology, and Department of Biochemistry and Biophysics, Texas A&M University, 77843-4466, College Station, TX, USA. |
| |
Abstract: | 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental toxin that activates the aryl hydrocarbon receptor (AhR) and disrupts multiple endocrine signaling pathways. T47D human breast cancer cells express a functional estrogen receptor alpha (ERalpha) and AhR, and treatment of these cells with 17beta-estradiol (E2) or TCDD resulted in a rapid proteasome-dependent decrease in immunoreactive ERalpha and AhR proteins (>60-80%), respectively. E2 did not affect the AhR, whereas TCDD induced proteasome-dependent degradation of both the AhR and ERalpha in T47D and MCF-7 human breast cancer cells, and these responses were specifically blocked by proteasome inhibitors. Thus, TCDD-induced degradation of ERalpha may contribute to the antiestrogenic activity of AhR agonists and this pathway may be involved in AhR-mediated disruption of other endocrine responses. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|