Macrophage-derived cathepsin L promotes epithelial-mesenchymal transition and M2 polarization in gastric cancer

Figure 5 Cathepsin L knockdown impairs macrophage-induced gastric cancer tumorigenesis in vivo. A: Experimental design of the animal study. Wild type male BALB/c nude mice had MKN45 cells implanted into the subcutaneous space and were mixed with either sh cathepsin L (CTSL) or shNC tumor-associated macrophage (TAM); B: Morphological characteristics of tumors in the MKN45 + shNC TAM, MKN45 + shCTSL TAM, MKN45 alone, and shNC TAM groups; C: Volume of tumor growth at the indicated time points over 3 days. The error bars represent the SD; D: Tumor weight and volume ex vivo. The error bars represent the SD. ^bP < 0.01; ^aP < 0.05 according to one-way analysis of variance (ANOVA); E: Immunohistochemistry analysis of mouse tumor sections from different groups stained for CTSL, E-cadherin, CD68, and Ki67 proteins. Magnification, 40 ×. Quantification of E-cadherin, CTSL, and CD68 protein expression was performed via Image J. The error bars represent the SD. NS: Not significant, P > 0.05; ^aP < 0.05; ^bP < 0.01; ^cP < 0.001 according to one-way ANOVA. TAM: Tumor-associated macrophage; HE: Haematoxylin and eosin; CTSL: Cathepsin L.