Figure 6. Effect of DDR2 inhibition on HT-1080 cell proliferation.

A. HT-1080 cells were transfected with control siRNA (Ctrl) or DDR2 siRNA. DDR2 expression was analyzed by immunoblotting. GAPDH was used as a loading control. B. HT-1080 cells were seeded in adult and old type I collagen 3D matrices at a density of 1.5 × 10⁴ cells/ml, with or without siRNA directed against DDR2. After 5 days of culture, cell density was evaluated by phase contrast microscopy. C. HT-1080 cells were seeded in adult and old type I collagen 3D matrices at a density of 5 × 10⁴ cells/ml, with or without DDR2 inhibitor nilotinib at 100 nM. After 5 days of culture, cell density was evaluated by phase contrast microscopy. Values represent the mean ± S.E.M. of three independent experiments (*p < 0.05, **p < 0.01, N.S. = not significant).