Fig. 5.

Dysregulation of replication initiation and induction of DNA damage and apoptosis by R9-caPep and Chk1 inhibitors. b) SK-N-BE(2) cells or c) SH-SY5Y cells were incubated for 12 h with 7.8 nM UCN-01, 30 μM R9-caPep, or 7.8 nM UCN-01 and 30 μM R9-caPep for 12 h. Untreated corresponding cells were used as controls. Cells were sequentially labeled with CldU and IdU for 15 min each. Following incubation with the nucleotide analogs, the cells were stained by fluorophore-coupled monoclonal antibodies to visualized CIdU and IdU incorporation. The relative distance between two neighboring replication origins was measured as illustrated in panel a. The distances between two neighboring origins from at least 15 DNA segments from cells under each treatment condition were graphed. d) SK-N-BE(2)c (left) or SH-SY5Y (right) cells were treated by 7.8 nM UCN-01, 30 μM R9-caPep, or both for 12 h. The intracellular levels of the indicated proteins were determined by Western blot.