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Systems Biology of Metabolic Regulation by Estrogen Receptor Signaling in Breast Cancer
Published on: March 17, 2016
Estrogen and hypoxia regulate estrogen receptor alpha in a synergistic manner
Jinhyung Michael Yi1, Hyeok Yi Kwon, Jung Yoon Cho
1Department of Bioscience and Biotechnology College of Engineering, Institute of Biotechnology, Sejong University, Kwang-Jin-Gu, Seoul, Republic of Korea.
Biochemical and Biophysical Research Communications
|December 17, 2008
Summary
Hypoxia and estrogen synergistically enhance estrogen receptor alpha (ERalpha) activity and promote its degradation in breast cancer cells. This suggests hypoxia may activate factors influencing ERalpha signaling pathways.
Area of Science:
- Molecular Biology
- Cancer Research
- Endocrinology
Background:
- Estrogen receptor alpha (ERalpha) plays a critical role in breast cancer development and progression.
- Hypoxia, a condition of low oxygen, is prevalent in solid tumors and influences cancer cell behavior.
Purpose of the Study:
- To investigate the synergistic effects of estrogen (E2) and hypoxia on ERalpha-mediated transactivation.
- To examine the impact of E2 and hypoxia on ERalpha degradation in human breast cancer cells.
Main Methods:
- Transient expression assays using ERalpha and ER-responsive reporter plasmids in HEK 293 cells.
- Treatment of MCF-7 breast cancer cells with E2 and hypoxia for 20 hours.
- Analysis of ERalpha degradation via a proteasome-dependent pathway.
Main Results:
- E2 and hypoxia synergistically increased ERalpha-mediated transcriptional activity.
- Combined E2 and hypoxia treatment induced a 95% degradation of ERalpha in MCF-7 cells within 20 hours.
- ERalpha degradation was mediated by a proteasome-dependent pathway.
Conclusions:
- Hypoxia and estrogen act synergistically to modulate ERalpha signaling in breast cancer.
- Hypoxia may stimulate novel factors that enhance ERalpha signal transduction pathways, contributing to breast cancer progression.
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