A RT-qPCR confirmed the stable knockdown of ESRP1 expression in endocrine-resistant cells using a shRNA lentiviral system (Mission TRC human shRNA constructs-Sigma); 2-control (LCC2 cells transduced with pLKO.1 control vector) and 2C1 and 2C3 (LCC2 cells transduced with pLKO.1 shRNA ESRP1). Clones were selected for expression verification (clone 1 and clone 3); 9-control (LCC9 cells transduced with pLKO.1 control vector), 9C2 and 9C3 (LCC9 cells transduced with pLKO.1 shRNA ESRP1. Clones were selected for expression verification (clone 2 and clone 3). * represents P <0.05; statistically significant. Data (mean ± SD) were calculated using two-way ANOVA based on three independent biological replicates. 