FIGURE 2.

Dexamethasone regulates VDR at the transcriptional level. A, actinomycin D and CHX inhibited transcription or translation of VDR. SCC cells were pretreated with Me₂SO, 10 μg/ml cycloheximide, or 10 μg/ml actinomycin D for 1 h followed by 100 nm Dex for 5 or 24 h. VDR was assessed at the transcriptional level (lower panel) and protein (upper panel) by using real time PCR and Western blot analysis, respectively. The results are representative of three independent experiments. B, time-dependent (0.5 to 48 h) induction of Vdr mRNA expression in SCC cells treated with ethanol vehicle control or 100 nm Dex. C, dose-dependent induction of Vdr mRNA. The cells were treated for 6 h with increasing concentrations of Dex or EtOH vehicle control. TaqMan® assay was used for relative quantitation of Vdr gene expression. The expression of the Vdr gene was normalized to mouse glyceraldehyde-3-phosphate dehydrogenase (Gapdh) expression and expressed relative to 0 h (B) or EtOH control (C) for each of the experiments being evaluated. The data represent the means ± S.D. of three technical replicates from one representative experiment. The experiments were repeated four times.