Fig. 5: BET inhibitors decrease the production of l-kynurenine in tumor cells.

a HPLC chromatograms of l-kynurenine for the reference (a) and in the medium of the cultured Ty-82 cells exposed to 0.1% DMSO (b), 1 μM JQ1 (c), 1 μM OTX015 (d), 1 μM NLG919 (e), 1 μM JQ1 plus 1 μM NLG919 (f), or 1 μM OTX015 plus 1 μM NLG919 (g) for 24 h. The arrowhead indicates the peak of l-kynurenine. b, c The relative l-kynurenine content (normalized ratio of area under HPLC curve) was determined by HPLC in the medium of the cultured Ty-82 and SKOV3 cells treated with the indicated compounds at 1 μM (b) or gradient concentrations of JQ1 (c) for 24 h. d, e Cell proliferation (expressed as normalized relative OD value) was measured by the SRB assay after 24-h exposure of the cells to the indicated compounds at 1 μM (d) or gradient concentrations (e) of JQ1. Data were from three independent experiments, and if applicable, were expressed as mean ± SD (error bar); *p < 0.05; **p < 0.01; ***p < 0.001; +, treated with the indicated drug