FIGURE 1.

ATRA stimulates DRA but not PAT-1 mRNA levels in Caco-2 cells. Caco-2 cells were treated with 10 μm ATRA for 8, 16, and 24 h in serum-free cell culture medium. RNA was amplified utilizing DRA (A) or PAT-1 (B) gene-specific primers for real-time PCR quantification. Data represent the relative expression of DRA or PAT-1 normalized to the respective GAPDH mRNA (internal control) levels. Results are expressed as fold-changes in mRNA levels in treated cells as compared with control. Data represent mean ± S.E. of 4 separate experiments. *, p < 0.05; **, p < 0.001 compared with control.