Fig. 3. BRCA1 is required for HU-induced S-phase arrest.
C. BRCA1-deficient and proficient HCC1937 cells were pretreated with 300 nM UCN-01for 1 hour prior to treatment with 2 mM HU for 24 hours. Cells were harvested and analyzed for cell cycle progression. Experiment was repeated three times and a typical experiment is presented.