Bacteria Strain Linked To Stomach Ulcers Can Induce Cancer 

Researchers with Vanderbilt-Ingram Cancer Center have discovered one of the clues that may explain how a common stomach bacteria, often connected to stomach ulcers, can trigger stomach cancer. 

Helicobacter pylori infects nearly 50 percent of the population and is the strongest known risk factor for gastric cancer. However, only a fraction of those infected with H. pylori develop cancer, so researchers have been trying to define the pathways that lead to cancer development.

Richard Peek Jr., M.D., director of the Division of Gastroenterology, Hepatology and Nutrition at Vanderbilt-Ingram Cancer Center, and colleagues at the Nashville Veterans Affairs Medical Center investigated a cag+ strain of H. pylori - a strain that increases risk of peptic ulcers and gastric cancer - in mouse models. They determined that an H. pylori protein switches on a cell receptor called Decay-accelerating factor (DAF) and that DAF protects infected gastric cells from the immune system. Their findings were published in the Aug. 29 issue of the Journal of Biological Chemistry.

"We found that the bacteria had actually co-opted a host cell protein, utilizing it as a receptor," said Peek. "This facilitated infection of the stomach and induction of gastric inflammation and injury."

Peek and his colleagues also found that up-regulation of DAF expression by H. pylori led to persistent inflammation in the stomach, making it easier for diseases like cancer to develop.