Download PDF
Exp Clin Endocrinol Diabetes 1994; 102(5): 399-408
DOI: 10.1055/s-0029-1211311
Original

© J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York

Binding of 2-hydroxyestradiol and 4-hydroxyestradiol to the estrogen receptor of MCF-7 cells in cytosolic extracts and in nuclei of intact cells

N. Schütze, G. Vollmer, W. Wünsche, A. Grote, B. Feit, R. Knuppen
  • Institut für Biochemische Endokrinologie, Medizinische Universität zu Lübeck, Germany
Further Information

Publication History

Publication Date:
15 July 2009 (online)

Also available at
  PDF Download  Permissions and Reprints

Summary

The catechol estrogens (CE), 2-hydroxyestradiol (2-OH-E2) and 4-hydroxyestradiol (4-OH-E2) were analyzed for their binding affinity to the estrogen receptor of MCF-7 cells. Applying a competitive binding assay to cytosols prepared from MCF-7 breast cancer cells, we measured a relative binding affinity of 23% (2-OH-E2) and 26% (4-OH-E2) compared to E2. Nuclear binding assays with the same cell line demonstrated a high specific binding with Kd's of 0.31 nM (2-OH-E2) and 0.21 nM (4-OH-E2). The relative binding affinity measured was 25% and 42% for 2-OH-E2 and 4-OH-E2, respectively. Based on this nuclear binding it can be concluded that the estrogen receptor occupied by CE is bound within the nucleus and might therefore be transcriptionally active.

Key words

Catecholestrogens - Estrogen receptor - MCF-7 cells - hormone-receptor interaction