Fig. 3

The effect of vorinostat on cell growth and cell cycle in vitro. a & b A549 cells were cultured with B[a]P or vorinostat at the concentrations indicated and for the times indicated to analyze their effect on cell growth. c To study the effect of vorinostat on cell growth in A549 cells exposed to B[a]P as long as possible, A549 cells were first pretreated with 5 μM B[a]P for 9 days (asterisk), and then followed by combination with 5 μM vorinostat for the times indicated. Viable cells were counted using trypan blue at each experiment, and data are presented as the mean ± standard error (SE) of triplicate experiments. d A549 cells were cultured with 5 μM vorinostat and/or 5 μM B[a]P as described in the Materials and Methods. After incubation, the cells were stained with propidium iodide, and cell cycle distributions were analyzed by flow cytometry. e The effect of vorinostat and/or B[a]P on cell cycle was also analyzed in H460 and H226 lung cancer cell lines in triplicate. The Y-axis indicates the percentage of cells in the S phase of cell cycle, and error bars indicate one standard deviation. The percentage of cells in the S phase was compared between vorinostat-treated and control cells and between B[a]P-treated and B[a]P/vorinostat-treated cells. The difference was analyzed using paired Student t-test. The symbols * and ** denote significant differences at P < 0.05 and P < 0.01, respectively