FIG 7.
TMPO-AS1 overexpression confers tamoxifen resistance. (A and B) Estrogen-responsive element (ERE)-based luciferase activities with the indicated concentrations of OHT were measured. Firefly luciferase values were normalized to Renilla luciferase values (n = 3). (B) ERE-based luciferase activities after treatment with OHT (10−11 M) and the indicated siRNAs. Firefly luciferase values were normalized to Renilla luciferase values (n = 3). (C and D) GREB1 (C) and PGR (D) mRNA levels in MCF-7 cells stably overexpressing TMPO-AS1 treated with OHT (10−9 M) for 48 h. Data are presented as mean fold changes ± SD versus values of vector-transfected MCF-7 cells (Vec #1) cultured in FBS-containing medium (n = 3). (E) Viability of control and TMPO-AS1-overexpressing MCF-7 cells on day 5 after OHT treatment analyzed by DNA assay. Values are presented as means ± SD versus the value of 0 M OHT for each cell (n = 5). (F) Viability of control and TMPO-AS1-overexpressing MCF-7 cells on day 5 after OHT and siRNA treatment, analyzed by DNA assay. Values are presented as means ± SD versus the value for OHT-free treatment (0 M) under each cell condition (n = 5).