Fig. 6.

Changes in gene expression in PCa xenograft tumors due to calcitriol and dietary vitamin D₃. Vehicle [control (Con)], calcitriol (Cal; 0.1 μg/mouse), and dietary vitamin D₃ (Vit D) were administered to male mice bearing PC-3 tumor xenografts as described in Fig. 1. Total RNA was isolated from harvested tumors and the mRNA levels of CYP27B1, VDR, and CYP24 (A), COX-2, the PG receptors EP2, EP4, and FP (B), 15-PGDH, p21, IGFBP-3, Bax, and Bcl₂ (C) were determined by quantitative RT-PCR as described in Materials and Methods. Relative mRNA expression for each gene in tumors from control mice was set at 1. Values represent mean ± se from six to 11 determinations. *, P < 0.05, **, P < 0.01 and ***, P < 0.001 compared with control.