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

Figure 2 Cathepsin L is more localized in the gastric tumor margin than in the bulk. A: Example diagram of the method for classifying tumor sections stained for cytokeratin, which defines the 2-mm-wide area away from the edge of the tumor as the tumor margin; scale bar, 500 μm; B-E: Representative immunohistochemistry images of the margin and bulk of each tumor section from patients with or without peritoneal metastasis stained for cathepsin L; scale bar, 50 μm. The number of positive cells in the tumor sections was quantified via Image J via the geometric mean of 3 representative views from each section. The data points are presented as the means ± SD. The error bars represent the SD; ^cP < 0.001; ^bP < 0.01 according to Student’s t test; F-H: Significant analysis of positive cell counts according to the metastasis state in the tumor margin or bulk region by Image J via the geometric mean of 3 representative views from each section. The data points are presented as the means ± SD. The error bars represent the SD; NS: Not significant, P > 0.05; ^aP < 0.05; ^cP < 0.001 according to Student’s t test. CTSL: Cathepsin L; PM: Peritoneal metastasis.