Loss of Rho GDIα and resistance to tamoxifen via effects on estrogen receptor α.

ABSTRACT:

Background

Estrogen receptor (ER) α is a successful therapeutic target in breast cancer, but patients eventually develop resistance to antiestrogens such as tamoxifen.

Methods

To identify genes whose expression was associated with the development of tamoxifen resistance and metastasis, we used microarrays to compare gene expression in four primary tumors from tamoxifen-treated patients whose breast cancers did not recur vs five metastatic tumors from patients whose cancers progressed during adjuvant tamoxifen treatment. Because Rho guanine dissociation inhibitor (GDI) α was underexpressed in the tamoxifen-resistant group, we stably transfected ERα-positive MCF-7 breast cancer cells with a plasmid encoding a short hairpin (sh) RNA to silence Rho GDIα expression. We used immun

SUBMITTER: Barone I 

PROVIDER: S-EPMC3071355 | biostudies-literature | 2011 Apr

REPOSITORIES: biostudies-literature