Role of SUMOylation in differential ERα transcriptional repression by tamoxifen and fulvestrant in breast cancer cells.

ABSTRACT: Antiestrogens (AEs) are widely used for treatment of estrogen receptor alpha (ERα)-positive breast cancer, but display variable degrees of partial agonism in estrogen target tissues and breast cancer (BC) cells. The fact that BC cells resistant to selective ER modulators (SERMs) like tamoxifen (Tam) can still be sensitive to pure AEs, also called selective ER downregulators, suggests different mechanisms of action, some of which may contribute to the more complete suppression of estrogen target genes by pure AEs. We report herein that pure AEs such as fulvestrant induce transient binding of ERα to DNA, followed by rapid release after 30-40 min without loss of nuclear localization. Loss of DNA binding preceded receptor degradation and was not prevented by proteasome inhibition. Chromatin wa

SUBMITTER: Traboulsi T 

PROVIDER: S-EPMC6514857 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature