β-catenin, leucine-rich repeat-containing G protein-coupled receptor 5 and GATA-binding factor 6 are associated with the normal mucosa-adenoma-adenocarcinoma sequence of colorectal tumorigenesis

In the present study, the expression of β-catenin, leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5) and GATA6 was investigated during the transition from normal mucosa through to adenoma and adenocarcinoma in colorectal tissue sections obtained from 65 patients with a pathological diagnosis of colorectal adenocarcinoma and a history of adenoma. Immunohistochemical staining of β-catenin, LGR5 and GATA6 was performed and evaluated. The nuclear expression of β-catenin and the cytoplasmic expression of LGR5 and GATA6 were increased in samples as they progressed from normal mucosa to adenoma and adenocarcinoma. However, membrane-bound β-catenin and nuclear GATA6 expression decreased. Positive correlations were observed between the expression of LGR5 and cytoplasmic GATA6 in adenoma (P=0.0005; r(s)=0.48) and adenocarcinoma samples (P=0.007; r(s)=0.38): However, no significant association was observed in normal mucosa (P=0.399). The expression of nuclear β-catenin was significantly increased in the serosal layer compared with the invasive layers of the colorectal wall in samples of adenocarcinoma (P=0.042). The results of the present study suggest that the nuclear expression of β-catenin and LGR5 and the cytoplasmic expression of GATA6 function together during the development of colorectal carcinoma.