Fig. 4: JQ1-induced cell death is c-Myc-dependent in NPC.

a CNE2-EBV−/+ and TWO3-EBV−/+ cells were treated with indicated concentrations of JQ1 for 24 h and analyzed for c-Myc level by western blot analysis. GAPDH served as a loading control. b CNE2-EBV−/+ and TWO3-EBV−/+ cells were treated with 1 μM JQ1 for 0, 0.5, 1, 3, 6, and 12 h and were analyzed for c-Myc level by western blot analysis. GAPDH served as a loading control. c Western blot analyses of the time-dependent effect of JQ1 treatment on c-Myc expression in SUNE1, 6-10B, CNE1 and HK1 cells. JQ1 was used at 1 μM. d Western blot analysis of RNAi efficiency of c-Myc siRNA in control CNE2-EBV−/+ cells and those transfected with c-Myc-targeting siRNA or negative control (NC) siRNA. Cell lysates were collected 48 h after transfection. e Cell viability of CNE2-EBV−/+ cells and those transfected with c-Myc-targeting siRNA or NC siRNA. Cell viability was measured 72 h after transfection. f–i Immunofluorescence images of f CNE2, (g) CNE2-EBV+, (h) TWO3, and (i) TWO3-EBV+ cells stained with antibodies against c-Myc. Actin was stained by FITC phalloidin and nuclei were stained by DAPI. Scale bar = 50 μm. j qRT–PCR analyses of BRD2, BRD3, and BRD4 in CNE2-EBV−/+ and TWO3-EBV−/+ cell lines treated with 1 μM JQ1 for 24 h. Results were normalized to GAPDH. The data are presented as mean ± SD of 3 independent repeats