Establishment of stable ERα-36-knockdown and -overexpression breast cancer cells

Lentivirus particles containing ERα-36-specific shRNAs and a scramble shRNA were obtained from Life Technologies Co. Ltd (Shanghai, China). The sequences targeting ERα-36 and the non-targeting sequence were listed in Table S1. After infecting Mb436 cells with 2 μg/mL of polybrene ¹⁷, ERα-36-stable-knockdown cells were selected using FACS. The ERα-36-knockdown cells were named as Mb436/sh36, whereas the control cells were named as Mock. The cells of ERα-36-overexpression were stably established as previously described ¹⁷. The ERα-36-overexpressing cells were named as Hs578T/ov36, whereas the vector-transfected cells were named as control.