Correlation of Wnt-2 expression and β-catenin intracellular accumulation in Chinese gastric cancers:: relevance with tumour dissemination

Wnt/beta-catenin signalling pathway is integrally associated with human tumour development and progression. Aberrant beta-catenin intracellular distribution has been found in gastric cancer, but the pattern of Wnt expression in stepwise gastrocarcinogenesis and its potential influence in beta-catenin distribution are still lesser known. By the methods of frozen tissue array-based immunohistochemistry, Western blot analysis and RT-PCR, a paralleled study was conducted to check Wnt2 expression and beta-catenin intracellular distribution in two major subtypes of gastric cancers (intestinal gastric cancer, i-GC and diffuse gastric cancer, d-GC) and their premalignant (intestinal metaplasia, IM and chronic gastritis, CG) and noncancerous counterparts. According to the results obtained and the clinical data collected, correlation of Wnt2 expression with beta-catenin translocalisation and their links with turnout dissemination were elucidated. The results demonstrated (1) that Wnt2 expression and cytoplasmic/nuclear beta-catenin accumulations appeared in most gastric cancers irrespective to their morphological phenotypes, (2) that over-expressed Wnt and nuclear translocalisation of beta-catenin were found in 68 and 58% of i-GCs and in 47 and 47% of d-GCs in a closely related pattern (P < 0.01) and (3) that co-existence of Wnt2 up-regulation/beta-catenin nuclear translocalisation were positively associated with lymph node metastasis (P < 0.05) as well as T-stage. These data indicate that Wnt/beta-catenin signalling pathway is activated in most of gastric cancers, which may play pivotal roles either in gastric cancer formation or in turnout invasion and dissemination. (c) 2004 Elsevier Ireland Ltd. All rights reserved.