CYP24A1 inhibition facilitates the anti-tumor effect of vitamin D3 on colorectal cancer cells

Figure 2 Time and dose dependent-changes in CYP24A1 mRNA expression in response to 1,25-D3 administration. A: Time course of changes in the cytochrome P450 component of the 25-hydroxyvitamin D3-24-hydroxylase (CYP24A1) mRNA expression in Caco-2 cells after the addition of 100 nmol/L active vitamin D3 metabolite 1,25-dihydroxyvitamin D3 (1,25-D3) to the cell culture supernatant. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH)-normalized CYP24A1 expression levels are shown as a percentage of the CYP24A1 level of the untreated control cells. Points indicate means ± standard deviation (SD) (^aP < 0.05 vs untreated control); B: Dose-dependent changes in CYP24A1 mRNA levels in Caco-2 cells after the addition of different amounts of 1,25-D3. GAPDH-normalized CYP24A1 expression levels are shown as a percentage of the CYP24A1 level of the untreated control cells. Points indicate means ± SD (^aP < 0.05 vs untreated control).