Figure 2.

TFN inhibits proliferation and decreases cellular uridine levels in PWR-1E and DU-145 cells. (A) The PWR-1E cells were treated for 24 hours with the indicated concentrations of TFN or an equal volume of the vehicle Me₂SO (control) dissolved in fresh culture medium. The cells were harvested and counted with a hemacytometer. The relative cell number in the TFN-treated populations is presented as a percentage of the 24-hour control. P < .001 compared with control. (B) The PWR-1E and DU-145 cells were cultured, harvested, and counted as described in panel (A) after 24- and 48-hour exposures to 50 µM TFN or Me₂SO (control). *P < .01 compared with the respective PWR-1E controls; **P < .01 compared with the respective DU-145 controls. (C) An assessment of the uridine levels in the DU-145 and PWR-1E cells after exposure to 50 µM TFN for the indicated times or Me₂SO (control, 0-hour TFN exposure). *P < .01 compared with the 0-hour DU-145 or PWR-1E control. (D) Representative PI (DNA) histograms for the treatments described in panel (B). The percentages of S-phase cells are presented above the histograms. (E) A summary of the cell cycle analyses for the treatments described in panel (B). *P < .001 compared with the respective DU-145 controls; **P < .001 compared with the respective PWR-1E controls. (F) DU-145 and PWR-1E cells were imaged at the indicated times after treatment with 50 µM TFN or Me₂SO (control). The arrows in the differential interference contrast images point to the cell nucleus. Scale bars, 18 µm.