Effects of LY294002 with or without EPO on the viability and survival of erythroid progenitor cells and DNA fragmentation. Day 8 cells that contained 61% ± 3% erythroid progenitor cells were suspended at a concentration of 1 × 106/mL in 1.0 mL serum-free medium with or without 2 U/mL EPO or 50 μmol/L LY294002. After incubation for 24 hours, cells were collected and washed twice in IMDM containing 0.3% BSA and then plated into serum-containing fibrin clots with 2 U/mL EPO. After 7 days’ incubation, the clots were fixed and stained with benzidine-hematoxylin. Data represent the mean ± SD of quadruplicates. (A) Viability; (B) percent expression for the number of erythroid colonies relative to the value of fresh day 8 cells as 100%; (C) DNA fragmentation using fresh day 8 cells as controls. *P < .05, **P < .01, ***P < .001.
