Figure 5.

The androgen response element is important for TGF-β/Smad3-enhanced AR transactivation. (A) DU145 cells were transiently cotransfected with AR (2 or 4 μg) and tyrosine aminotransferase–CAT, MMTV-CAT, or PSA-CAT (3 μg), in the presence (+) or absence (−) of DHT (10⁻⁸ M) or TGF-β (10 ng/ml). (B) DU145 cells were transiently cotransfected with AR (2 or 4 μg) and tyrosine aminotransferase–CAT, MMTV-CAT, or PSA-CAT (3 μg), and Smad3 expression vector (6 or 10 μg) in the presence (+) or absence (−) of DHT (10⁻⁸ M). Each CAT activity is presented relative to the transactivation observed in the absence of Smad3. All values represent the mean ± SD of three independent experiments.