Neoadjuvant tamoxifen synchronizes ERα binding and gene expression profiles related to outcome and proliferation.

ABSTRACT: Estrogen receptor alpha (ERα)-positive breast cancers are frequently treated with tamoxifen, but resistance is common. It remains elusive how tamoxifen resistance occurs and predictive biomarkers for treatment outcome are needed. Because most biomarker discovery studies are performed using pre-treatment surgical resections, the effects of tamoxifen therapy directly on the tumor cell in vivo remain unexamined. In this study, we assessed DNA copy number, gene expression profiles and ERα/chromatin binding landscapes on breast tumor specimens, both before and after neoadjuvant tamoxifen treatment. We observed neoadjuvant tamoxifen treatment synchronized ERα/chromatin interactions and downstream gene expression, indicating that hormonal therapy reduces inter-tumor molecular variability. ERα-syn

SUBMITTER: Severson TM 

PROVIDER: S-EPMC5085127 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature