Estrogen-Related Receptor Alpha (ERRa)-Coactivator Interactions as Targets for Discovery of New Anti-Breast Cancer Therapeutics
Abstract
The nuclear receptor estrogen receptor alpha (ERalpha) is a primary focus of the therapy of breast cancers. ERalpha-positive breast cancers have traditionally been treated with the anti-estrogen tamoxifen, or with inhibitors of aromatase. ERalpha-negative breast cancers do not respond to anti-estrogen treatment; instead, current therapeutics, such as Herceptin, have focused on the transmembrane tyrosine kinase receptor ErbB2 (HER2) because it is often overexpressed in ERalpha-negative tumors and correlates with a poor prognosis. Estrogen-related receptor alpha (ERRalpha) has sequence similarity to ERalpha, but ERRalpha does not bind estrogens. In some cases ERRalpha is constitutively active, which is likely determined not only by its interaction with coactivators, but also in part by post-translational modifications occurring via the ErbB2 (HER2) signaling pathways. Thus, ERRalpha probably plays a key role in the etiology and progression of a subset of breast cancers. We believe that the ERRalpha-coactivator interaction is a promising target for new chemotherapeutic drug development. We have generated and characterized a set of murine monoclonal antibodies for use in studying the biology of ERRalpha. We are now using some of those antibodies in gentle immunoaffinity chromatography to determine ERRalpha-associated proteins. Using in vitro assays, we will study the binding properties of ERRalpha with known coactivators like transcriptional intermediary factor 2 (TIF2), as well as any ERRalpha-associated proteins we may find during immunopurification. In the future, using a luminescence resonance energy transfer-based high-throughput screen previously developed in our laboratory, we hope to identify small molecules that interfere with the binding of ERRalpha with these coactivators.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2006
- Accession Number
- ADA452545
Entities
People
- Richard R. Burgess
Organizations
- University of Wisconsin–Madison