Figure 2. ZEB1 increases tumor cell adherence to Col1 through α₁β₁ integrin.

(A) Western blot analysis of Itga1 in 393P_ZEB1 cells transfected with Itga1 shRNAs (shItga1) or control shRNA (shCTL). (B) Cell adhesion to Col1 or plastic (no coating) at indicated time points. n = 4. *P = 0.01; ***P < 0.001. (C) Percentages of spread cells on collagen at indicated time points. ***P < 0.001. (D) Western blot analysis of Itga1 in 393P cells transfected with Itga1 expression vector or control vector (Vec). (E) Cell adhesion to Col1 or plastic at indicated time points. n = 4. *P = 0.03; **P = 0.005. (F) Percentages of spread cells on Col1 at indicated time points. ***P < 0.001. (G–I) Cell adhesion to collagen or plastic. H1299 cells transfected with ITGA1 shRNA or control shRNA (shCTL) and Itga1 expression vector or empty vector (Vec) (G), 344SQ cells transfected with shRNA against Itgb1 or control shRNA and siRNA against Itga1 or control siRNA (siCTL; H), and 393P cells transfected with Iga1 expression vector or control vector and siRNA against Itgb1 or siCTL (I) are shown. n = 4. **P < 0.01; ***P < 0.001. (J) Schema showing tail vein injection of red fluorescent protein–labeled (RFP-labeled) 344SQ cells into mice. (K) Percentage of RFP-positive cells in mouse lungs at 4 hours after injection. (L) Green fluorescent protein–labeled (GFP-labeled) and RFP-labeled 344SQ transfectants were coinjected into mice and the resulting micrometastases were imaged and quantified. Data are shown as the mean ± SEM from a single experiment incorporating biological replicate samples (n = 3, unless otherwise indicated) and are representative of at least 2 independent experiments. Two-tailed Student’s t test for 2-group comparisons; 1-way ANOVA test for multiple comparisons.