Fig. 1

Nogo-B receptor (NgBR) is highly expressed in the tamoxifen resistant MCF-7-TamR and T47D-TamR cells. a Colony formation assay was performed as described in “Methods”. Wild-type MCF-7 and tamoxifen-resistant MCF-7-TamR cells were treated with different concentrations of 4-OHT (0, 1 and 5 μM). b Quantification of colony number presented in colony formation assays of MCF-7 and MCF-7-TamR cells. c Colony formation assay of wild-type T47D and tamoxifen-resistant T47D-TamR cells treated with different concentrations of 4-OHT (0, 1 and 5 μM). d Quantification of colony number in colony formation assays of T47D and T47D-TamR cells. e, f mRNA level of NgBR was increased in MCF-7-TamR and T47D-TamR cells as compared to wild-type MCF-7 and T47D cells, respectively. The relative amount of NgBR mRNA level was normalized to glyceraldehyde-3-phosphate dehydrogenase (GAPDH). g NgBR protein level was increased in MCF-7-TamR cells. Protein levels of Nogo-B, epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), estrogen receptor alpha (ERα), p53 and survivin in MCF-7 and MCF-7-TamR cells were determined using western blot analysis. h Quantitative analysis of protein levels using ImageJ and normalized to the housekeeping gene β-actin. Data are presented as fold changes in MCF-7-TamR cells compared to MCF-7 cells. The data are from three separate repeat experiments, and are presented as the mean ± SD (*p < 0.05, n = 3)