Fig. 4. Quisinostat can concomitantly inhibit FGFR signaling with erdafitinib.

Western blots showing the combinational effects of erdafitinib and quisinostat on FGFR signaling activation. Cells were first treated by quisinostat or DMSO control for 2 days, followed by the treatment by erdafitinib or DMSO control in no serum media for 3 h. Then FGFR signaling was stimulated by 50 ng/ml FGF1 + 10 µg/ml heparin and analyzed by western blotting. β-actin (ACTB) was used as standard loading control. Red arrowheads represent the position of FGFR3 fusions. Red boxes represent the signaling pathways that can be further inhibited by the combinational treatment, compared to each individual drug treatment alone. 1E, 1 nM erdafitinib; 2E, 2 nM erdafitinib; 25Q, 25 nM quisinostat; 50Q, 50 nM quisinostat; E + Q, the combination of erdafitinib and quisinostat.