Adiponectin deficiency enhances colorectal carcinogenesis and liver tumor formation induced by azoxymethane in mice

Figure 4 COX-2 overexpression in colorectal tumors of KO mice. Immunohistochemical staining for COX-2 in colorectal tumors using rabbit anti-mouse COX-2 polyclonal antibody. Immunoreactive COX-2 expression is observed in the epithelium and periluminal stromal cells of the tumors (Arrowheads). A: Representative sections of colorectal tumors in WT mice: e: Boxed area is shown at a higher magnification; B: Representative sections of colorectal tumors in KO mice: j: Boxed area is shown at a higher magnification. Original magnification: × 20 for b, c, d, f, g, h; × 40 for a, e, i, j; × 200 for the boxed area in e and j. C: Statistical analysis of immunoreactive COX-2 expression in colorectal tumors. COX-2 expression was higher in colorectal tumors of KO mice (n = 11) compared with WT mice (n = 9; ^aP < 0.05, Wilcoxon rank sum test). Horizontal lines: mean value of COX-2 immunoreactivity in colorectal tumors of WT or KO mice. D: Significant correlation between COX-2 immunoreactivity and PCNA-labeling index in colorectal tumors (r = 0.89, P < 0.001, Spearman’s rank correlation). WT mice (n = 9), KO mice (n = 11).