INHIBITION OF BREAST AND OVARIAN-CARCINOMA CELL-GROWTH BY 1,25-DIHYDROXYVITAMIN D-3 COMBINED WITH RETINOIC ACID OR DEXAMETHASONE

This study examined the growth inhibitory effects of combining 1,25-di hydroxyvitamin D-3 (calcitriol) with retinoic acid or dexamethasone ag ainst cultured breast and ovarian carcinoma cells, Retinoic acid (12.5 -50 nM) increased the effectiveness of calcitriol (12.5-50 nM) against MCF-7 and NIH:OVCAR3 cells, with synergistic interactions at two of t he three ratios tested, Dexamethasone augmented calcitriol effects, wi th synergism at 0.05 and 0.1 nM dexamethasone in MCF-7 cells and 5 nM in Caov-4 ovarian cells, This study showed favorable interactions for calcitriol-retinoic acid and calcitriol-dexamethasone combinations in breast and ovarian cancer cell lines.