Figure 3.

RARRES1 and LXN are induced by retinoic acid in primary prostate cultures. (a) qRT-PCR expression data quantifying the relative expression of RARRES1 and (b) LXN expression after treatment of primary epithelial cell cultures (enriched for SC, TA and CB cells) derived from BPH (n=3) or CaP (n=3) with 100 nℳ atRA for 72 h. All expression values are relative to an RPLPO endogenous control. Within each subpopulation, expression of all dimethyl sulfoxide (DMSO)-treated and atRA-treated samples was normalized to the DMSO-treated sample showing the lowest expression of RARRES1 or LXN (set at 1). Average expression denoted by a horizontal line. (c) RAR-α, -β and -γ expression was detected by immunofluorescence in primary epithelial cultures derived from CaP, treated with 500 nℳ atRA for 24 h or a DMSO control. Cells were counterstained with 4′-6-diamidino-2-phenylindole to enable nuclear visualization. White scale bar represents 10 μm. Antibody controls using rabbit or mouse IgG instead of primary antibody and secondary antibody only. (d) Luciferase activity in primary prostate epithelial cell cultures derived from BPH and (e) CaP transfected with a RARE reporter plasmid, and 12 h after transfection, cells were treated with various concentrations of atRA for a further 24 h. Luciferase activity was normalized to the values of the cells transfected with a negative control plasmid (lacked RARE regulatory elements). Statistical significance values were measured by the Student's t-test (*P<0.05, **P<0.01, ***P<0.001). Filled shapes in a,b indicate primary samples from different patients.