Figure 2.

DDR2 is a key player in matrix stiffness–induced EMT. (a) Western blot analysis of DDR1 and DDR2 in H1299 cells incubated on a PAG with the indicated stiffness. (b) Western blot analysis of DDR2 in H1299 cells expressing mock or anti-DDR2 shRNA. (c) Quantification of proliferation of H1299 cells expressing mock or anti-DDR2 shRNA with indicated stiffness and duration. Data represent the mean of three independent experiments ± SEM. ^** P < 0.01. (d) Western blot analysis of DDR2, pERK, ERK, and p21 in H1299 cells expressing mock or anti-DDR2 shRNA under the indicated conditions. (e) qRT-PCR analysis of expression of TWIST1, ACTA2, CDH2, VIM, and CDH1 in H1299 cells expressing mock or anti-DDR2 shRNA. Data represent the mean of three independent experiments ± SEM. ^** P < 0.01. (f) Immunostaining of N-cadherin and the nucleus in H1299 cells expressing mock or anti-DDR2 shRNA. Mock shRNA–expressing H1299 cells in the presence of 10 ng ml⁻¹ TGF-β served as positive controls. (g) Kaplan–Meier curves of overall survival among patients with lung cancer, including lung adenocarcinoma and squamous cell lung carcinoma.