M A T E R I A L S AND M E T H O D S The growth-inhibitory effects of ketoconazole, an antifungal agent which inhibits arachid0nic acid iip0xygenases and cyt0chr0me P-450 enzymes, were tested in human colon and breast cancer cell lines. In the serum independent HT29-S-B6 colon cell clone, ketoconazole reduced cell proliferation and [3H]thymidine incorporation in a dose-dependent fashion, with a ...