Fig. 5

The dual-target compound DW22 significantly inhibits the growth of cisplatin-resistant cells by regulating HtrA1 mRNA levels. a MTT assay indicating the efficacy of cisplatin in cisplatin-resistant NSCLC cells following incubation with DW22, cisplatin and DW22 + cisplatin for 72 h. DMSO was set as the control group that comparing to treatment groups. b The combination index for DW22 + cisplatin in cisplatin-resistant NSCLC cells was calculated using the Calcusyn program. CI < 0.90 indicates synergism, 0.90–1.10 indicates an additive effect and > 1.10 indicates antagonism. c, d The inhibitory effects of DW22 and CDDP, separately and together, on C migration and d invasion in cisplatin-resistant NSCLC cells. The final concentrations were: CDDP (5 μM), DW22 (13 μM), CDDP+DW22 (5 μM/13 μM) e-h MTT assay data indicating the sensitivity to DW22 in e H460/CDDP cells transfected with HDAC1 siRNA or control siRNA, f H460 cells transfected with RXRα siRNA or control siRNA, g A549 cells transfected with HtrA1 siRNA or control siRNA, and h A549/CDDP cells transfected with a HtrA1 overexpression (S328A or WT) or control plasmid. ^*P < 0.05, ^**P < 0.01, ^***P < 0.001, as compared to the VEGF group or scramble or Mock group. ^#P < 0.05, ^##P < 0.01, as compared to the DW22 group. ^&P < 0.05, as compared to the CDDP group