Figure 6
Overexpression of miR-22 inhibits GC growth and represses the peritoneal dissemination and distal pulmonary metastases in vivo. (a) Photographs of mice injected with agomir-NC-SGC-7901 or agomir-22-SGC-7901. In all, 2 × 106 SGC-7901 cells transfected with agomir-NC (5 μM) or agomir-22 (5 μM), respectively, were suspended in 200 μl phosphate-buffered saline for each mouse and were injected subcutaneously into the axillary fossae of the female nude mice (n=8). (b) Graph representing tumor volumes at the indicated days during the experiment for the two groups: agomir-NC and agomir-22. Data are presented as mean±S.D. **P<0.01. (c) Tumor weight averages between agomir-NC-SGC-7901 and agomir-22-SGC-7901 mice groups at the end of the experiment (day 35). Data are presented as mean±S.D. (n=8). **P<0.01. (d and e) Representative tumor nodules in the abdominal cavity of nude mice that were injected with SGC-7901 cells containing agomir-NC or agomir-22. In all, 1 × 106 SGC-7901 cells transfected with agomir-NC or agomir-22, respectively, were injected into the abdominal cavity of nude mice (n=6). Four weeks after injection, the mice were killed and the macroscopic nodules in abdominal cavity of the mice were counted. The arrowheads point to the tumor nodules in the abdominal cavity. Histogram reveals the number of macroscopic nodules. Data are presented as mean±S.D., ***P<0.001. (f) qRT-PCR assays determine miR-22 expression in the metastasized nodules (28 days after injection). (g) Western blotting assays reveal the protein expression of MMP14, MMP2, Snail and E-cadherin in the metastasized nodules (day 28). GAPDH serves as an internal control. (h) HE staining of lung tissue isolated from nude mice (n=10), which were injected with 1 × 106 SGC-7901 cells containing agomir-NC (5 μM) or agomir-22 (5 μM) via lateral tail veins (× 200 magnification) (35 days after injection). The metastasis nodules are indicated by arrows. (i) The graph gives the incidences of metastasis in mice that had received lateral tail injections of each cell line. Ten mice in each group, Fisher’s exact test: *P<0.05
