Fig. 3
The anti-tumor effect of shikonin on A549 cells by inducing necroptosis in vivo. a Athymic nude mice were injected (s.c.) with 2 × 106 A549 cells (0.2 mL cell suspension) in both hind legs. When the implanted tumors reached a volume of 90–130 mm3, the mice were randomly divided into two groups with five mice per group. The figure shows the macroscopic appearance of tumors in mice after treatment with shikonin (20 mg/kg, by i.p., once per day) or PBS. Tumor volume was estimated using the following formula: volume = L × W2/2. Points, means of five animals; bars, SD. *p < 0.01 compared with the control. b Image shows the size of tumors at the end of the experiments. c The tumors were weighed. The data represent mean ± standard deviation (SD) of five animals. *p < 0.05 compared to the control. d CT and 3D images of the orthotopic injection of lung cancer in athymic nude mice. e The specimens were fixed in 4% paraformaldehyde for HE staining, as shown at the microscopic level. Images were obtained at ×40 and ×200. f Western blot analysis showed that the RIP1 expression levels in tumor tissue was higher in the shikonin group than in the control group. Data are representative of two independent experiments