Fig. 2.

Nogo-B receptor (NgBR) knockdown decreases the resistance of MCF-7-TamR cells to tamoxifen. a NgBR knockdown increases 4-OHT-induced apoptosis of MCF-7-TamR cells; 4-OHT, 5 μM. The apoptotic cells were detected by Annexin V-PI staining as described in “Methods”. The total number of cells in the Q2 and Q4 quadrant were counted as apoptotic cells. b Percentages of apoptotic MCF-7-TamR cells are presented in the bar graph. c NgBR knockdown decreases cell viability of MCF-7-TamR cells treated with 4-OHT. Cell viability was determined using trypan blue staining. MCF-7-TamR cells were treated with 4-OHT (5 μM) for 48 h. The viable cell number in the non-silencing (NS) group is set as 100%. d NgBR knockdown decreases the clonogenenicity of MCF-7-TamR cells treated with 4-OHT (5 μM). Clonogenic survival assay was performed as described in “Methods”. e Quantification of colony number in colony formation assays as described in Fig. 2d. The data were repeated in three separate experiments, and are presented as the mean ± SD (*p < 0.05, n = 3)