Vasconcelos-Nóbrega CCosta, C.Vala, HelenaCosta, X. A.Santos, L.Oliveira, P. A.2013-02-192013-02-192012Vasconcelos-Nóbrega C, Costa C, Vala H, Colaço A, Santos L, Lopes C, Oliveira PA (2012). Β cathenin in mice: expression in normal urothelium and in chemically induced pre-neoplastic and neoplastic lesions. Abstract book of 30th Meeting of the European Society of Veterinary Pathology (ESVP), Annual Meeting of European College of Veterinary Pathology (ECVP) and 24th Annual Meeting of the Spanish Society of Veterinary Pathology (SEAPV): 162http://hdl.handle.net/10400.19/1553Background: Catenins are adhesion molecules that link cadherin molecules to cytoskeleton. The association of catenins to cadherins is a key step in the function of intact adhesion complexes, and alterations in catenin molecules can lead to the disruption of cell-cell adhesion, resulting in tumour aggressiveness and invasiveness in neoplastic disease. Material and methods: Urothelial lesions were chemically induced by BBN in ICR mice, and evaluated by immunohistochemistry to determine the staining pattern of β-cathenin. Results: In normal urothelium, 70% of β-catenin expression was at the cellular membrane level. In simple hyperplasia, the same pattern was observed in 66.67% of lesions. Nodular hyperplasia was observed only once with a membrane pattern. In dysplasia a 100% cytoplasmic pattern was seen. Invasive carcinoma showed an heterogeneous pattern with areas where the membrane, cytoplasm or nucleus were stained. On squamous metaplasia, the staining pattern was confined to the membrane, however, with heterogeneous immunoreactivity. Conclusions: β-cathenin is a good marker of the progression of bladder tumours chemically induced in mice by BBN.engβ-catheninmicebladder tumourschemically inducedBBNconference object