Forskolin and rolipram induce G1 and G2/M cell cycle arrest and apoptosis in CEM cells.
CEM cells were cultured with 20 μM forskolin, 20 μM rolipram, and 1 μM dexamethasone in various combinations for 48 hours. (A) DNA content per cell was measured by PI staining and flow cytometry. Deconvolution analysis of the cell cycle profiles was performed to estimate the percentages of cells in G1, S, and G2/M phases (Table 2), as well as (B) the percentage of cells with subdiploid DNA content, indicative of apoptosis. (C) The fluorescence profile of cells bound to EGFP–annexin V fusion protein is plotted with the percentage of highly fluorescent cells shown above the bar, indicating apoptotic cells. (D) Lysate of untreated cells (broken line) and cells treated with forskolin and rolipram (solid line) for various time intervals were assayed for caspase-3 activity using a fluorescent substrate. Activity is measured in arbitrary units of relative fluorescence.
