Fig 2: ß1-integrin is involved in COX-2-induced tumour growth and cell invasion in NSCLC.(A) Effects of ß1-integrin expression on COX-2-induced cell migration and invasion in LLC cells. COX-2-transfected LLC cells were infected with lentivirus silencing the ß1-integrin expression (termed COX-2 + ITGB1 RNAi cells). Total protein was isolated and visualized using anti-ß1-integrin and anti-COX-2 antibodies. Levels of ß-actin served as a loading control. The cell migration and invasion assays were performed in LLC control cells, ITGB1 RNAi cells, COX-2 overexpression cells and COX-2 + ITGB1 RNAi cells. Results are presented as the mean ± SEM (n = 3). (B) Effects of ß1-integrin expression on COX-2-induced tumour growth and cell invasion in xenograft models. Four-week-old female C57/B6 mice were randomized into three groups (n = 8). Group 1 was implanted with wild-type LLC cells (control group). Group 2 was implanted with COX-2 overexpression cells. Group 3 was implanted with COX-2 + ITGB1 RNAi cells. Representative images of tumours from each group were shown. The tumour growth curve and a comparison of average tumour weight on the final day among three groups are shown. (C) HE staining of tumours and adjacent lymph nodes (LN) sections showing histopathological features of the xenografts in mice. Scale bars = 100 µm (10×). Scale bars = 50 µm (40×).

Fig 3: Modulation of Integrin ß1 signaling by Lgl1 is essential for epithelial migration(A and B) Effect of Lgl1 loss on Integrin ß1 signaling activation, as measured by the phosphorylation status of Integrin ß1 downstream components Fak and Paxillin using western blot analysis. (A) Assays were performed using control and Lgl1 null MECs. (B) Relative levels of active Fak and Paxillin as measured by the ratio of phosphorylated and total forms of Fak and Paxillin.(C–E) Effect of Lgl1 overexpression on Fak and Paxillin phosphorylation in the HC11 cell line using western blot analysis. (C) Relative levels of Lgl1 overexpression were measured by a qPCR analysis. (D) Assays were performed using control and Lgl1 GOF HC11 cells. (E) Relative levels of active Fak and Paxillin as measured by the ratio of phosphorylated and total forms of Fak and Paxillin.(F–J) Effect of Itgb1 overexpression on collective migration using the HC11 cell line. (F) Relative levels of Itgb1 overexpression were measured by a qPCR analysis. Time course of control (G–G?) and Itgb1 GOF (H–H?) HC11 cell aggregate migration toward beads pre-soaked in FGF10. Quantification of the daily (I) and total (J) displacement of HC11 cells with and without Itgb1 overexpression.Data are mean ± SD. Statistical analysis was performed using unpaired Student’sttest. *p < 0.05; **p < 0.01; ***p < 0.001; ****p< 0.0001; N.S., not significant. See also Figure S5.