Regulation in the Expression of Virulence Factors of Helicobacter pylori by the Interaction between AGS Cells and H. pylori

Abstract

Helicobacter pylori (H. pylori) was defined as a Class 1 pathogenic carcinogen by WHO causing chronic inflammation in the stomach, thereby increasing the risk of gastric cancer. Various virulence factors are involved in the mechanism of gastric cancer caused by H. pylori infection. These virulence factors usually show different expression levels depending on the environment of H. pylori, which can affect the risk of gastric cancer. In this study, the differences in the expression levels of major virulence factors of H. pylori depending on the environment were investigated by comparing expression levels of H. pylori cultured with AGS or alone. As a result, there was no difference in the expression of adhesins of alpA, sabA, and babA even after co-culture with AGS cells. In addition, the co-culture environment did not induce a difference in the expression levels of flaA and ureB. On the other hand, H. pylori co-cultured with AGS cells showed low expression levels of cagA, groEL, and oipA and high expression of vacA compared to H. pylori cultured alone. Our results suggest that not only the presence or absence of virulence factor genes but also differences in expression levels should be considered when evaluating the risk of gastric cancer after H. pylori infection based on the virulence factors.