RNA-seq of Tamoxifen-sensitive MCF-7 and Tamoxifen-resistant MCF-7TR breast cells.

Tamoxifen (TAM) is the most commonly prescribed antiestrogen used to treat patients with estrogen receptor (ER)-positive breast cancer, leading to improved survival. Many cancer patients benefit from initial therapy. However, among these patients who receive this adjuvant endocrine therapy, resistance almost inevitably develops, leading to eventual relapse and death. Overcoming resistance thus remains a major clinical challenge. There is currently no available therapeutic strategy for TAM-resistance, which remains one of the main causes of breast cancer mortality. The cellular processes underpinning TAM resistance were analyzed by RNA-seq.