English
Albanian
Arabic
Armenian
Azerbaijani
Belarusian
Bengali
Bosnian
Catalan
Czech
Danish
Deutsch
Dutch
English
Estonian
Finnish
Français
Greek
Haitian Creole
Hebrew
Hindi
Hungarian
Icelandic
Indonesian
Irish
Italian
Japanese
Korean
Latvian
Lithuanian
Macedonian
Mongolian
Norwegian
Persian
Polish
Portuguese
Romanian
Russian
Serbian
Slovak
Slovenian
Spanish
Swahili
Swedish
Turkish
Ukrainian
Vietnamese
Български
中文(简体)
中文(繁體)
Biochemical Pharmacology 2006-Aug

Proteasome-independent down-regulation of estrogen receptor-alpha (ERalpha) in breast cancer cells treated with 4,4'-dihydroxy-trans-stilbene.

Only registered users can translate articles
Log In/Sign up
The link is saved to the clipboard
Kannan V Balan
Yongbao Wang
Siming W Chen
Jin-Chun Chen
Li-Fang Zheng
Li Yang
Zhong-Li Liu
Panayotis Pantazis
James H Wyche
Zhiyong Han

Keywords

Abstract

Treatment of cells with estrogens and several pure ERalpha antagonists rapidly induces down-regulation of the alpha-type estrogen receptor (ERalpha) in the nucleus by mechanisms that are sensitive to the proteasome inhibitors, MG132 and clasto-lactacystin-beta-lactone. Hence, it is believed that these ER ligands induce down-regulation of ERalpha by proteasome-dependent mechanisms, which serve to control both the amount of transcriptional activity and the level of ligand-bound ERalpha in cells. In this study, we observed that treatment of cultured MCF-7 and T47D human breast cancer cells with the low affinity ER ligand, 4,4'-dihydroxy-trans-stilbene (4,4'-DHS), inhibited the transcriptional activity of ERalpha and induced slow and gradual decrease in the amount of ERalpha protein (henceforth referred to as down-regulation of ERalpha). The 4,4'-DHS-induced down-regulation of ERalpha in MCF-7 cells involved a mechanism that was insensitive to the two most specific proteasome inhibitors, clasto-lactacystin-beta-lactone and epoxomycin, but sensitive to MG132 at concentrations exceeding that required for maximal inhibition of the proteasome in MCF-7 cells. Therefore, 4,4'-DHS appears to induce down-regulation of ERalpha by a proteasome-independent mechanism. Here, we present data to show that both 4-OH and 4'-OH are critical for the ability of 4,4'-DHS to induce down-regulation of ERalpha and suggest that 4,4'-DHS provides a useful scaffold for development of novel ERalpha antagonists.

Join our facebook page

The most complete medicinal herbs database backed by science

  • Works in 55 languages
  • Herbal cures backed by science
  • Herbs recognition by image
  • Interactive GPS map - tag herbs on location (coming soon)
  • Read scientific publications related to your search
  • Search medicinal herbs by their effects
  • Organize your interests and stay up do date with the news research, clinical trials and patents

Type a symptom or a disease and read about herbs that might help, type a herb and see diseases and symptoms it is used against.
*All information is based on published scientific research

Google Play badgeApp Store badge