FIGURE 8.

CID755673 inhibited cell proliferation in LNCaP and PC3 cells. A and B, LNCaP (A) or PC3 (B) cells were plated in triplicates in 24-well plates. Cells were allowed to attach overnight. A cell count at day 1 was made, and then either a vehicle (DMSO) or CID755673 at the indicated concentrations was added. Cells were counted daily for a total of 6 days. Fresh media and inhibitor were added every 2 days. The means of triplicate determinations were plotted over time. The experiment was repeated twice and results from one representative experiment are shown. Right panel (B), the effect of the weaker analogue CID797718 on PC3 cell proliferation. Results from one of two independent experiments are shown. ^*, p < 0.05; ^**, p < 0.01; ^***, p < 0.001. C, CID755673 induced apparent morphological changes. Phase-contrast images of PC3 cells after 6 days of CID755673 treatment are shown. D, CID755673-induced G₂/M phase cell cycle arrest. PC3 cells were incubated with a vehicle (DMSO) or varying concentrations of CID755673 for 6 days. Media with fresh inhibitors were replenished daily. Cell cycle distribution was evaluated by flow cytometry after propidium iodide labeling of fixed cells. One of two independent experiments is shown.