Figure 7: EMT signalling activation in human samples with CRC.

(a–f) Double immunofluorescence on human samples with CRC using ZEB1 (red) and ECAD (green). (a) CRC primary tumour and (c,e) liver metastasis, showing ZEB1-positive/ECAD-negative cells invading the desmoplastic area in primary tumour and in liver metastasis. Numbers on a,c,e indicate different cell types observed on the slide as follows: 1 for colorectal primary (in a) or metastatic cells (in c), 2 for stroma cells and 3 for hepatocytes. Scale bars, 20 μm. Magnifications from the boxes b,d,f are also represented in b,d,f single 4′,6-diamidino-2-phenylindole, ECAD and ZEB1 staining. ZEB1-positive cells (labelled with an arrowhead) in the liver metastasis are either observed next to colorectal tumour cells (d) or surrounded by hepatic tissue (f). Scale bars, 4 μm. (g) The activity scores computed for the Notch, p53 and Wnt pathways in human colon cancer samples from Tumour Cancer Genome Atlas data set. The data points represent primary tumour samples grouped as non-metastatic (blue) and metastatic (red) according to the observation of distant metastases. The bottom and top of the box correspond to the first and third quartiles of the activity score values, and the band inside the box represents the median. P values are calculated using the two-sample t-test between the two groups.