Fig. 5

The common emergence of MET upregulation does not confer afatinib-acquired resistance in ESCC. a The levels of the EMT markers (E-cadherin and vimentin) between resistant and parental models. b MET expression was upregulated in all three afatinib-resistant models. Cells were harvested after treatment with 200 nM afatinib for 48 h. The PDX lysates used were the same as those described in Fig. 4d. All assays were repeated three times independently. c KYSE450-R and EC109-R cells were treated with increasing concentrations of afatinib in the presence or absence of 1 μM crizotinib for 72 h, and CCK-8 assays were performed to assess cell viability. Data are presented as the means ± SDs of three independent assays. d After MET was knocked down in KYSE450-R and EC109-R, cells were treated with increasing concentrations of afatinib for 72 h, and then CCK-8 assays were performed to assess cell viability. Data are presented as the means ± SDs of three independent assays. e Resistant cells were treated with 200 nM afatinib alone or in combination with 1 μM crizotinib for 48 h. f Resistant cells after MET knockdown were treated with 200 nM afatinib for 48 h. All experiments were repeated three times independently