IGF-1 promotes the growth and metastasis of hepatocellular carcinoma via the inhibition of proteasome-mediated cathepsin B degradation

Figure 3 Cathepsin B mediated IGF-1-induced tumor growth and metastasis in diabetic mice. A: Hepa 1-6 cells grew faster in diabetic mice than in normal mice. In total, 2 × 10⁶ Hepa 1-6 cells were injected s.c. into the backs of mice. The data are presented as quantified tumor weights (mean volumes ± SE); B: Metastasis developed rapidly in diabetic mice. In total, 3 × 10⁶ Hepa 1-6 cells were injected into the lateral tail vein of each mouse. The data are presented as representative bioluminescence images of lungs and metastatic nodule numbers in the lungs (mean ± SE); C: Hepa 1-6 cells expressing control shRNA or CTSB shRNA1 (2 × 10⁶) were injected sc into the backs of the mice. The data are presented as the mean volumes ± SEM at the indicated time points; D: Hepa 1-6 cells expressing control shRNA or CTSB shRNA1 (3 × 10⁶) were injected into the lateral tail vein of each mouse. The data are presented as the number of metastatic nodules in the lungs (mean ± SE). ^bP < 0.01; ^cP < 0.001 vs control.