FIGURE 1.

GZD824 is a pan‐FGFR inhibitor. (A) Chemical structure of GZD824; (B) GZD824 inhibits FGFR1/2/3/4 kinase activities in vitro by FRET‐based Z′‐Lyte assay; (C) GZD824 possess binding activities with FGFR1 in H1581 lung cancer cells by CETSA; (D) GZD824 possess binding activities with FGFR1‐V561F in Ba/F3‐FGFR1‐V561F cells by CETSA. Cells were treated with DMSO or GZD824 (1000 nM for H1581, 100 nM for Ba/F3‐FGFR1‐V561F) for 3 h, respectively. Drug‐treated cells were heated at gradient temperature from 38℃ to 57.8℃ for 3 min and then lysed, centrifuged to separate the soluble fractions from precipitates. The soluble fractions were analyzed by immunoblotting. Relative band intensities were plotted as a function of temperature followed a sigmoidal trend. The corresponding sigmoidal curve is on the right. GZD824 protected FGFR1 against thermal degradation, suggesting that the compound interacts with the receptor