Effect of SDF-1α on apoptosis induced by growth factor withdrawal.

Factor-starved CD34⁺ cells prepared from human bone marrow (A) or MO7e cells (B) were further incubated in serum-free media in the presence of either 100 ng/mL SDF-1α alone, 10 ng/mL SLF alone, or the combination of these 2 cytokines. After 4 days, cells were stained with PC-5–conjugated APO2.7 mAb and analyzed by flow cytometry. (A) Values in histogram represent percent of APO2.7⁺ cells. This is representative of 3 separate experiments. (B) Columns represent the average percent of APO2.7⁺ cells ± SD of 3 separate experiments. *P < .01 versus SLF alone.