RNA-sequencing of normal breast tissue samples before and after 12-week anti-progestin (ulipristal acetate) treatment

Vacuum-assisted biopsy (VAB) from normal breast tissue were obtained from women participating in the Breast Cancer - Anti-Progestin Prevention Study 1 (BC-APPS1). A baseline VAB was performed in the luteal phase of the menstrual cycle and a second VAB was performed after a 12-week anti-progestin (ulipristal acetate, daily 5mg oral tablet) treatment. For each VAB a small piece of breast tissue was snap frozen in theatre. RNA was extracted using the RNeasy Plus Micro Kit (Qiagen) and indexed PolyA libraries were prepared using 100ng of total RNA. Paired-end 75bp sequencing was carried out on a NextSeq 500 sequencer (Illumina Inc.).