Effects of inhibiting the proteasomal degradation of estrogen receptor alpha on estrogen receptor alpha activation under hypoxic conditions.
Hypoxia, which is intimately associated with the biology of breast carcinomas, modulates the level of estrogen receptor (ER) alpha expression and transactivation. We investigated the effect of blocking ER degradation on ERalpha-mediated transactivation under hypoxic conditions using the proteasome inhibitor MG132. Pretreatment with MG132 blocked hypoxia-induced degradation of ERalpha protein. Our data imply that ERalpha proteasomal inhibition is linked to receptor transactivation under hypoxia.
Park
Yeo Myeong
YM
College of Life Science, Institute of Biotechnology, Department of Bioscience and Biotechnology, Sejong University, Seoul 143-747, Korea.
Cho
Jung Yoon
JY
Koo
Young Do
YD
Lee
Young Joo
YJ
D000970:Antineoplastic Agents / Q000494:pharmacology; D001943:Breast Neoplasms / Q000378:metabolism; D002277:Carcinoma / Q000378:metabolism; D045744:Cell Line, Tumor; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000378:metabolism*; D007976:Leupeptins / Q000494:pharmacology*; D061988:Proteasome Inhibitors; D015533:Transcriptional Activation
D000970:Antineoplastic Agents; D047628:Estrogen Receptor alpha; D007976:Leupeptins; D061988:Proteasome Inhibitors; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde