A breakdown of the Hippo pathway in gastric cancer.

BACKGROUND/AIMS: The Hippo pathway is a newly discovered signaling pathway. In mammals, the Hippo pathway was reported to be a tumor-suppressor signaling that inhibited cell proliferation and promoted cell apoptosis. Inactivation of the Hippo pathway resulted in massive cell growth, enlargement in organ size and eventually cancer formation. The aim of this study was to investigate the expression of core component proteins of the Hippo pathway, Mst1/2,S Sav1 and Lats1, in normal gastric mucosa, intestinal metaplasia and gastric cancer, and to explore the role of the Hippo pathway in gastric cancer.

METHODOLOGY

Two-step immunohistochemical staining was used to detect the expression of Mst1/2, Sav1 and Lats1 in 46 cases of normal gastric mucosa, 37 cases of intestinal metaplasia and 78 cases of gastric cancer.

RESULTS

The expression of Mst1/2 and Lats1 was down-regulated in gastric cancer compared with that in normal gastric epithelium and adenoma. The Sav1 expression showed an increased trend from normal mucosa through intestinal metaplasia to gastric cancer, though there was no statistically significant difference. The expression of Sav1 and Lats1 in gastric cancer with lymph node metastasis was significantly lower than that without lymph node metastasis.

CONCLUSIONS

A breakdown of the Hippo pathway may play a role in tumorigenesis and metastasis of gastric cancer.