Analysis of Wnt and β-catenin Expression in Advanced Colorectal Cancer

Wnt/β-catenin signaling plays an important role in colorectal cancer (CRC). Wnt has many sub-types and it is uncertain which of them affect progression of CRC. We analysed 201 patients who underwent curative surgery for CRC. We investigated the relationship between the expression of Wnt and β-catenin proteins and prognosis using immunohistochemistry. The high expression of Wnt1 correlated with high expression of nuclear and cytoplasmic β-catenin (p=0.0004, p=0.02). The high expression of Wnt5a also correlated with high expression of membrane β-catenin (p=0.03). In multivariate analysis, lymph node metastasis (p=0.046) and high expression of nuclear β-catenin (p=0.04) were independent prognostic factors for survival. The expression of nuclear β-catenin is a useful predictive marker in CRC. It is suggested that Wnt1 may be the main activator of the β-catenin signaling pathway and that Wnt5a may stabilize adherens junctions, thereby suppressing the epithelial-mesenchymal transition.