Figure 1.

Dose-dependent response was evaluated at different concentrations of Trastuzumab (1 to 10 μg/ml), ascending every 7 days. Cells keeping alive for 7 days during the dosage ascending were collected and cultured with 10μg/ml Trastuzumab. As the growth rate became synchronous with the parental wild type (WT-SKBR-3) cells, the Trastuzumab-resistant cells (TR-SKBR-3) were obtained. Cell vitality of WT-SKBR-3 and TR-SKBR-3 was exactly similar at the starting dose. Subsequently the gap of survival rate became obvious as dose ascending (A). Furthermore, YAP/TAZ inhibitor-1 (Medchemexpress LLC, New Jersy, USA) was synchronously employed in WT-SKBR-3 and TR-SKBR-3 cells while SD of Trastuzumab was performed, in order to evaluate the relationship of YAP/TAZ expression and therapeutic efficacy of Trastuzumab.YAP/TAZ inhibitor reversed the drug resistance, thereby inducing inhibition of vitality in TR cells. By contrast, TR cells without YAP/TAZ inhibitor always retained the outstanding advantage in vitality (B).