Fig. 4. Colon-derived metastatic tumors with null Trp53 mutations can undergo epithelial-mesenchymal transition (EMT).

a Photomicrograph of an H&E-stained section showing a moderately differentiated tumor lesion found in the lymph node of a representative AKP^fl/fl mouse 2.5 months post TAM injection (top panel). Immunohistochemical stains for this lesion show strong nuclear expression of β-catenin, strong membrane expression of E-cadherin and absence of vimentin expression (bottom three panels). b Photomicrographs of H&E-stained sections showing the poorly differentiated lesions found in the cecum, lymph node, and lung of another AKP^fl/fl mouse 4 months post TAM injection (top panel). All these lesions show strong nuclear expression of β-catenin, loss of E-cadherin expression and strong expression of vimentin, indicating that the primary and metastatic lesions found in this mouse have undergone EMT (bottom three panels). The representative photomicrographs of H&E-stained sections were shown with low power magnification for orientation; the serial sections were subjected to immunohistochemical staining and the boxed area with stains for β-catenin, E-cadherin and vimentin were shown as high power magnification. Scale bars: 20 μm for all the images.