EpoR mRNA and protein levels in normoxia versus hypoxia in cell lines. (A) Expression of EPOR, CYCLOB, VEGF, and BNIP3 mRNA was examined in the human tumor cell lines shown in Figure 1 following growth in normoxia (N) or hypoxia (H) using a quantitative bDNA assay. Each point represents the mean level of transcript for each cell line from duplicate experiments from 3 independent cultures. Vertical bars represent the mean, and error bars represent the 95% confidence interval. (B) EpoR, CycloB, and BNIP3 Western blots of cell lysates from N and H treated cells from the 5 cell lines that express higher levels of EpoR protein and MCF-7 (1.6 × 105 cells/lane). CYCLOB is the loading control and a non–hypoxia-regulated gene. BNIP3 is a known hypoxia-regulated gene.
