Figure 4.

A: Effects of Epo on hypoxia-induced cell death. Tumor cells were incubated in normoxic, hypoxic, and hypoxic with Epo (10 U/ml) for 24 hours. Values represent the means with SE from at least three independent experiments. Hypoxia significantly reduced cell survival (comparison between control and hypoxia treatment; *, P < 0.01) and the effect was prevented by addition of Epo (comparison between hypoxia and hypoxia plus Epo treatment; #, P < 0.01). B: Effects of Epo on DTIC and cis-platin-induced cell death. The tumor cells were pretreated with Epo (0, 10, and 100 U/ml) for 2 hours before the addition of chemotherapeutic agents. Values represent the means with SE from at least three independent experiments. Epo significantly increased cell viability in response to DTIC treatment at certain doses. The effects of Epo on cis-platin-treated cells were less prominent. *, Significant difference between 100 U/ml Epo and controls (P < 0.05); #, significant difference between 10 U/ml Epo and controls (P < 0.05). C: Epo increases mitochondria potential in melanoma. a: WM 793 was in a serum-free medium for 72 hours. b: WM 793 was in a serum-free medium for 24 hours and then supplemented with 2 U/ml of Epo for an additional 48 hours. The red fluorescence indicates high mitochondrial potential and aggregates of JC-1. There is an increase of mitochondria membrane potential after Epo treatment.