Figure 5.

Lamin B1 KD promotes tumor growth and metastasis through a RET-dependent mechanism. (A–D) Control, lamin B1 KD, RET KD, and lamin B1/RET double-KD LLC1 cells were injected intravenously into the tail vein of C57BL/6 mice for 20 d (n = 6 each). Mice were sacrificed and examined for tumor metastases in the lungs. Macroscopic appearance (A, upper panels) and H&E staining (A, lower panels) of representative lungs. Scale bars, 2 mm. (B–D) Quantification of the metastatic area (B), microscopic tumor volume (C), and metastatic nodules (D) of mice injected with control, lamin B1 KD, RET KD, and lamin B1/RET double-KD LLC1 cells. (E–H) Control, lamin B1 KD, RET KD, and lamin B1/RET double-KD LLC1 cells were injected subcutaneously into the flanks of C57BL/6 mice for 20 d (n = 6). (E) Quantification of the macroscopic tumor volume at different days after injection. (F) Upper panels: Representative image of the mice at day 20 after injection. Lower panels: Mice were sacrificed and the subcutaneous tumors were removed. (G and H) Spontaneous metastasis in lungs. H&E staining of representative lungs (G) and quantification of the number of metastatic nodules in the lungs (H) of mice injected with control, lamin B1 KD, RET KD, and lamin B1/RET double-KD LLC1 cells (n = 6). Arrows indicate metastatic nodules. Scale bars, 2 mm. Statistical analysis was performed using Student’s t test with two-tailed distribution. Data are mean ± SEM. *, P < 0.05; **, P < 0.01; ***, P < 0.001 (B–E and H).