Fig. 5

Overexpression of SOX2OT affected cell proliferation in tamoxifen-resistant (TAMR) breast cancer cell lines. (A, B) Dose-dependent characterization of tamoxifen resistance in TAMR-V and TAMR-H breast cancer cells. Parental MCF-7, TAMR breast cancer cells were treated indicated concentrations of tamoxifen or tamoxifen-4OH for 48 h. Viable cells were quantified using MTT assay. (C, D) TAMR cells were overexpressed using SOX2OT plasmid and then treated with tamoxifen or tamoxifen-4OH. The expression of SOX2OT was observed to be lower in TAMR cells than in control cells, and the cell viability increased when overexpressed again, especially in TAMR-H cells (p < 0.001). Comparison of the two groups was performed using Student’s t-test, with error bars representing the standard deviation of at least three independent experiments