Figure 4.

Suppression of guanylin requires APC LOH in an FAP patient. (a) Representative immunofluorescence of guanylin and GUCY2C in an FAP patient (Biobank ID: #027). Samples were obtained from the colon of this patient that captured the progression of transformation from normal adjacent tissue (NAT; monoallelic APC loss), through premalignant polyp and invasive adenocarcinoma (biallelic APC loss). Representative images shown, guanylin (green), GUCY2C (magenta), DAPI (blue). (b) Quantification of guanylin and GUCY2C mRNA by qRT-PCR in NAT (n = 2 patients), polyp (n = 2 patients) and adenocarcinoma (n = 1 patient). (c) Graphical representation for APC-dependent mechanism of guanylin suppression created with Biorender.com. Scale bar = 100 µm.