Fig. 6

rHuEPO promoted HepG2 cells proliferation under hypoxia. a, b MTT assay. After 5, 10, 50 or 100 IU/mL rHuEPO was added into the cell culture media, HepG2 cells were cultured under normal oxygen (a) or hypoxia (b) for 24, 48 and 72 h. **p < 0.01 vs control at the same time point, ***p < 0.001 vs control at the same time point. c–g After HepG2 cells were treated with 10 IU/mL rHuEPO or/and 0.5 μg/mL soluble-EPOR, cells were cultured under hypoxia for 24, 48 and 72 h. c MTT assay. d Histogram plots of CFSE fluorescence of cells. The value (inset) for the percentage of cells that divided at least once (top left) and the average number of cell divisions (bottom left corner) are indicated for each sample. e Histograms of percentage of divided cells. Data shown are mean ± SEM of at least three independent experiments, each with three replicate wells. f Expression of PCNA protein in HepG2 cells. Total cell lysates were subjected to immunoblotting with specific antibody. β-actin serves as loading control. g The relative densities of PCNA. Results are representative of three independent experiments. H0, H24, H48 and H72 indicated cells cultured under hypoxia for 0, 24, 48 and 72 h, respectively. *p < 0.05 rHuEPO vs control, **p < 0.01 rHuEPO vs control at the same time point, ***p < 0.001 rHuEPO vs control, ^# p < 0.05 rHuEPO + soluble-EPOR vs rHuEPO at the same time point, ^## p < 0.01 rHuEPO + soluble-EPOR vs rHuEPO at the same time point. Student’s t test is indicated