Fig. 4

The combination of trichostatin A (TSA) and JQ1 synergistically inhibited the growth of osimertinib sensitive and resistant H1975 cells. a Osimertinib resistant (H1975-OR) and osimertinib sensitive parental (H1975-P) cells were treated with TSA (2 μmol/L), JQ1 (10 μmol/L), or their combination for 24 h, and then subjected to western blot analysis. b Cells were treated with TSA, JQ1, or their combination in different concentrations as indicated for 3 days and then subjected to sulforhodamine B (SRB) assays, followed by combination index assays using CompuSyn software. Points, mean; bars, SD. c–e, The tumor size (c), tumor weight (d), and body weight (e) of the xenograft mouse model are presented. The vehicle control, TSA (0.5 mg/kg/d), JQ1 (100 mg/kg/d), or their combination was administered for 21 day. In C: columns, mean. In D: points, individual tumor weight; horizontal line, mean tumor weight. In E Points, mean; bars, SD; *, P < 0.05 vs. control; #, P < 0.05 vs. TSA; $, P < 0.05 vs. JQ1