RBMS3 inhibited the proliferation of breast cancer cells in vitro. (A, B) real-time (RT)-PCR and Western blot analyses showed effective upregulation of RBMS3 following RBMS3-pcDNA3.1 transfection. (B) MCF-7 cells were transfected with RBMS3-pcDNA3.1 or pcDNA3.1. (C) The proliferating capacity of transfected cells was evaluated using an MTT assay at 0, 24, 48, 72, and 96 h subsequent to transfection. *p < 0.05 compared to the pcDNA3.1 group.