Figure 2.
Assessment of H2Ax phosphorylation in sequential marrow samples from individual patients undergoing treatment with cytarabine and SCH 900776 at dose levels 2 to 5. Aliquots of whole-cell lysates containing protein from 5 × 105 marrow mononuclear cells (median 80% blasts; range, 64%–98%) were subjected to SDS-PAGE and immunoblotting for phosphorylated H2Ax or, as a loading control, c-Raf (lanes 4–18). Duplicate blots probed for lamin B1 and histone H1 yielded similar results. Each blot also contained whole-cell lysates from 3 × 105 HL-60 cells treated for 24 hours with diluent, 1 µmol/L cytarabine, or 1 µmol/L cytarabine + 1 µmol/L SCH 900776 (lanes 1–3, respectively). Dashed line indicates 2 different exposure times for the phospho-H2Ax blot from patients 406 and 505.