Figure 3. Nilotinib anti‐tumour activity is mediated by DDR1 kinase inhibition in CRC.

• A
  Biochemical analysis of the nilotinib‐resistant DDR1 T701I mutant. Tyrosine phosphorylation and DDR1 expression level in HEK293T cells transfected with the indicated DDR1 constructs and stimulated with 40 μg/ml collagen I for 18 h in the presence or not of the indicated concentration of nilotinib.
• B–D
  Nilotinib anti‐tumour activity is abrogated by DDR1 T701I expression in CRC cells. (B) Western blot analysis of DDR1 levels in HCT116 cells expressing the indicated shRNAs and infected with the indicated DDR1 constructs (wild type, WT; T701I; kinase dead, KD). (C) Invasion assays in Boyden chambers of the indicated cell lines after incubation with DMSO or 50 nM nilotinib (mean ± SEM; n = 4; **P < 0.01 Student's t‐test). (D) DDR1‐depleted HCT116 cells infected with the indicated DDR1 constructs were injected in the spleen of nude mice (n = 5/group) and treated daily with 50 mg/kg nilotinib, starting at day 1 post‐injection (oral administration). After 4 weeks, livers were removed. A representative image of liver for each group and the metastatic index of each animal are shown (mean ± SEM; *P < 0.05 Student's t‐test).
• E, F
  Nilotinib inhibits DDR1‐mediated invasive and metastatic activity of CRC cells. (E) Invasion assays in Boyden chambers of the indicated SW620 cell lines that were incubated with DMSO or 100 nM nilotinib (mean ± SEM; n = 3; *P < 0.05; **P < 0.01 Student's t‐test). (F) After inoculation of SW620 cells that overexpress DDR1 in the spleen, nude mice (n = 21 for the DMSO group and n = 14 for the nilotinib group) were treated daily with DMSO or 50 mg/kg/d nilotinib as indicated, starting at day 7 post‐injection (oral administration). After 4 weeks, livers were removed. A representative image of liver for each group, the metastatic index and the relative ctDNA level of each animal are shown (mean ± SEM; *P < 0.05; **P < 0.01 Student's t‐test).

Source data are available online for this figure.