Figure 1.
Cyclin D1 is required for serum-induced RCS proliferation. (A) RCS cells were serum-starved for 3 d, followed by stimulation with 10% FBS or control serum-free medium. Cells were labeled with BrdU in 4-h intervals. The percentage of cells incorporating BrdU was determined by FACS and is shown. (B) RCS cells were serum-starved for 3 d, followed by stimulation with 10% FBS or control medium for the indicated intervals, and harvested for the analyses of cyclin D1 protein expression by Western blot. Equal gel loading (5 × 105 cells/lane) was documented by probing for actin protein expression. (C) RCS cells (150,000/well) were plated, serum-starved for 3 d, and restimulated with 10% FBS in the presence of control or cyclin D1 antisense oligonucleotides. Cells were counted after 48 h of stimulation. The average and SD from two independent experiments (performed in triplicate wells each) are shown.