A possible role of GDDR in the development of Helicobacter pylori-associated gastric cancer.

Helicobacter pylori (H. pylori) infection plays an important part in the development of gastric carcinoma. GDDR has been confirmed as a tumor suppressor gene in gastric tumorigenesis. However, the underlying mechanism of GDDR in H. pylori-induced carcinogenesis is not well known. The aim of this study is to investigate the clinicopathological significance and possible molecular mechanism of GDDR in gastric cancer associated with H. pylori. Western blot, real-time quantitative PCR (qRT-PCR), and immunohistochemistry were used to detect the expression level of GDDR with or without H. pylori infection. The function and possible related molecular mechanisms of GDDR were further explored in vitro and in vivo. The variability of GDDR expression appeared in the early stage of gastric carcinogenesis with positive H. pylori infection status. GDDR might inhibit the progression of normal gastric epithelial cells to cancer cells by suppressing NF-kappaB signaling pathway, which in turn could be regulated by H. pylori infection. Our results suggested, for the first time, that the gradual change in GDDR expression might not only be directly related to H. pylori infection but also be an early molecular event in the development of gastric carcinoma.