FIG. 4.
Steroid-independent and cell-autonomous activation of AKT activity by SRC-3 overexpression. (A) Steroid-independent induction of AKT activity by SRC-3 overexpression. Immunoblot analysis with the phospho-Ser473 antibody for AKT, which detects activated AKT. Clone no. 48 of LNCaP-SRC-3 cultured in the medium with 10% charcoal-stripped serum was treated with mifepristone (10−8 M) in the presence or absence of the androgen agonist R1881 (2 nM). (B) Cell-autonomous induction of AKT activity by SRC-3 overexpression. Immunoblot analysis of clone no. 48 and parental LNCaP cells cocultured in the medium separated by a 0.45-μm membrane which is permeable to growth factors. Similar results are also seen for other stable clones.