Fig. 5

Pharmacologic inhibition of DDR1 reduces gastric cancer tumor growth. a MKN28 cells (1 × 10⁷ in 50 μl) were injected into the subcutaneous layer of athymic nude mice (n = 10). Five mice were sacrificed on day 5 post injection, and the remaining 5 mice were sacrificed after 12 days. Collagen in the tumor was assessed by Masson’s trichrome stain, and the expression of DDR1 was evaluated by immunohistochemistry. b MKN28 cells (1 × 10⁷ in 50 μl) were injected subcutaneously into nude mice. Animals were treated with vehicle (control; n = 8) or 25 μg/g of 7rh benzamide (7rh; n = 6) three times a week via oral gavage. The representative pictures of the mice right before sacrifice show the different tumor size between two groups. c Tumor volume and body weight were measured during drug administration, and tumors were harvested on day 17 post tumor cell injection. The error bars represent standard error of the mean (SEM) and an asterisk (*) represents P < 0.005, calculated by Mann-Whitney U test. d Harvested tumors were subjected to immunohistochemistry for phosphorylated DDR1 (pDDR1), phosphorylated PYK2 (pPYK2), and E-cadherin. Quantification of pDDR1 signal intensity is shown. Scale bar = 20 μm. The error bars represent standard error of the mean (SEM) and an asterisk (*) represents P < 0.005, calculated by Mann-Whitney U test