Editors' Selections from Relevant Scientific Publications

The contribution of the bacterium Helicobacter pylori to gastric cancer is well-established, but new research reveals another gut microbial species that also directly promotes tumorigenesis. Having previously linked Streptococcus anginosus with gastric cancer risk in H. pylori-free patients, Fu et al. embarked on a deeper investigation of this pathogen. They demonstrate that S. anginosus induces inflammation, metaplasia, and dysplasia in the stomach after transplantation into mice, even when introduced on its own into germ-free animals. Subsequent experiments demonstrate that S. anginosus accelerates growth of both allografted and chemically induced gastric tumors in mice. Finally, the authors uncover molecular mechanisms by which this bacterium engages with epithelial cells: it binds to the Annexin A2 receptor via its surface protein TMPC. This binding activates MAPK pathway, stimulating proliferation of the cells and inhibiting apoptosis. Consequently, it disrupts gastric barrier function and promotes tumorigenesis.

Fu...