Effect of src kinase inhibitor on K562 and K562-R cell survival, PARP cleavage, and LYN phosphorylation.

(A) K562-R cells were incubated with 1 μM CGP-76030 for 30 and 60 minutes (top) or longer intervals (12-24 hours, bottom), and equal protein (30 μg) cell lysates were analyzed for changes in LYN phosphorylation (top) or PARP cleavage (bottom). The blot was stripped (as previously described in Donato et al19) and reprobed with anti-LYN. (B) K562 and K562-R cells were incubated with the indicated concentration of CGP-76030 for 48 hours in a 96-well plate before cell survival was estimated by MTT assay. Each data point represents the average ± SEM of 4 determinations. Untreated (control) cell survival was set at 100%.