Extended Data Figure 7: BET bromodomain inhibitors reverse ERG-mediated functions in an isogenic cell line system.

a, b, qRT–PCR and immunoblot showing overexpression of ERG in RWPE and PC3 prostate cell lines. Data represent mean ± s.e.m. (n = 3). c, BET inhibitors block ERG-induced RWPE and PC3 cell invasion. RWPE and PC3 cells stably expressing either LacZ or ERG were treated with DMSO (n = 4), 500 nM JQ1 (n = 4) or I-BET762 (n = 4) for 24 h before plating in Matrigel-coated Boyden chambers. After 48 h cell invasion was quantified. Left, representative photomicrographs of invaded cells are shown with a 100 μm scale bar (lower Boyden chamber stained with crystal violet). Right, bar graph shows fold change in cell invasion, with DMSO-treated LacZ-expressing cells set to 1. Data represent mean ± s.e.m. from one of three independent experiments. d, BET inhibitors reverse ERG-induced gene transcription. GSEA of the ERG target gene signature (see Methods) in RWPE cells overexpressing ERG (RWPE-ERG) and PC3-ERG cells treated with JQ1 or I-BET762 (500 nM) for 24 h. ERG-induced genes are repressed by JQ1 or I-BET762 treatment. e, GSEA using a random gene set shows no significant positive or negative enrichment by JQ1 or I-BET762 treatment in RWPE-ERG and PC3-ERG cells. NS, not significant; ***P ≤ 0.0001 by two-tailed Student’s t-test.