Fig. 3.

Measurement of H3K27me3 level in PC3 cells using the DELFIA format. (A–C) Titration of PC3 cells in H3K27me3 DELFIA cell-based assay. The bar graph illustrates the responses of the negative (uninhibited) controls (▪) versus positive (100% inhibited) controls (□) at various cell densities (2,500–20,000 cells per well) for 1-, 2-, and 3-day treatment. (D) The concentration response of reference inhibitors in H3K27me3 DELFIA cell-based assay. Cells were incubated with a compound for 3 days at 37°C in 5% CO₂. Evaluation of the cellular inhibitory activity of the reference inhibitors generated average IC₅₀ values of 11.7±1.6 and 0.32±0.07 μM for RBC124 (▪) and DZNep (▾), respectively. The IC₅₀ value (average±SEM) from three independent determinations was calculated. Error bars denote SEM. DELFIA, dissociation-enhanced lanthanide fluorescence immunoassay.