To investigate the effect of Wnt signaling pathway activated on occurrence of hilar cholangiocarcinoma.

Clinical data of 129 patients with hilar cholangiocarcinoma and 45 patients with congenital choledochal cyst undergoing surgical resection in the First Affiliated Hospital of Sun Yat-sen University between July 1998 and May 2007 were retrospectively studied. Among the 129 patients with hilar cholangiocarcinoma, 91 were males and 38 were females with the average age of (56±23) years old. Among the 45 patients with congenital choledochal cyst, 32 were males and 13 were females with the average age of (39±11) years old. The informed consents of all patients were obtained and the local ethical committee approval had been received. The tissue microarray of the pathological specimen was made. Wnt signal protein (Wnt) -2, β-catenin and T cell factor-4 (TCF-4) were treated by immunohistochemical staining. The positive expression of 3 indexes Wnt-2, β-catenin and TCF-4 observed simultaneously was considered as activated Wnt signaling pathway. The rate comparison of two groups was conducted using chi-square test.

According to results of immunohistochemical staining, the positive expression of Wnt-2 in hilar cholangiocarcinoma tissues was observed in the appearance of brown granules in cytoplasm, while the positive expression of β-catenin and TCF-4 was observed in the appearance of brown granules in cell nucleus. The incidence of simultaneous positive expression of the 3 indexes Wnt-2, β-catenin and TCF-4 in hilar cholangiocarcinoma tissues was 54% (70/129), which was significantly higher than 29% (13/45) in congenital choledochal cyst (χ²=11.2, P<0.05).

The activation of Wnt signaling pathway may be one of the important molecular biological mechanisms of the occurrence of hilar cholangiocarcinoma.