Figure 4
L1CAM in fibroblasts promotes cancer cell proliferation via integrin α5β1. (a,b) (left panel) Western blot analysis of integrin β1 expression in MDA-MB-231 (a) and A431 cells (b) treated with control (CTR) or integrin β1 (ITGB1) siRNA. (middle panel) Secreted luciferase activity from siRNA-transfected GLuc-expressing MDA-MB-231 (a) and A431 cells (b) co-cultured with mock or L1CAM-expressing Mint3 KO MEFs. (right panel) Secreted luciferase activity from siRNA-transfected GLuc-expressing MDA-MB-231 (a) and A431 cells (b) co-cultured with WT or Mint3 KO MEFs. (c, d) (left panel) Western blot analysis of integrin α5 expression in MDA-MB-231 (c) and A431 cells (d) treated with control (CTR) or integrin α5 (ITGA5) siRNA. (middle panel) Secreted luciferase activity from siRNA-transfected GLuc-expressing MDA-MB-231 (c) and A431 cells (d) co-cultured with mock or L1CAM-expressing Mint3 KO MEFs. (right panel) Secreted luciferase activity from siRNA-transfected GLuc-expressing MDA-MB-231 (c) and A431 cells (d) co-cultured with WT or Mint3 KO MEFs. (e, f) (left panel) Western blot analysis of L1CAM expression in MDA-MB-231 (e) and A431 cells (f) transfected with control (CTR) or L1CAM siRNA. (right panel) Secreted luciferase activity from GLuc-expressing MDA-MB-231 (e) and A431 cells (f) transfected with control (CTR) or L1CAM siRNA. In a–f, error bars indicate the s.d. (n=3). The data were analysed using a t-test. **P<0.01. The data shown in a–f are representative of three independent experiments with similar results. *P<0.05, **P<0.01. NS, not significant.
