Figure 1.

mRNA and protein expression of CYP24A1 in cell lines. The parental cell line (HT29) was stably transfected with a GFP‐tagged plasmid (HT29^GFP) or a plasmid encoding for the fusion protein CYP24A1‐GFP (HT29^{CYP24A1‐GFP}). Cells were treated for 6 h (a) or 24 h (b) with 10 nM 1,25‐D₃, 100 nM 1,25‐D₃ or vehicle control. mRNA levels of CYP24A1 were assessed by real time qRT‐PCR. All values were set relative to total RNA calibrator and are presented as 2^−ΔΔCT. Bars represent mean ± SEM of three independent experiments. (c) Cells were stained for CYP24A1 expression on coverslips after 20 h of treatment with 100 nM 1,25‐D₃, or vehicle. Vector GFP expression is detectable in HT29^GFP and HT29^{CYP24A1‐GFP} cells but is absent in the parental cell line. Basal CYP24A1 (red) protein expression is low with exception of HT29^{CYP24A1‐GFP} cells but is inducible with 1,25‐D₃. White line represents 50 μm.