Bacteria Strain Linked To Stomach Ulcers Can Induce Cancer - Vanderbilt-Ingram Cancer Center Researchers Find New Assault Mechanism

Main Category: GastroIntestinal / Gastroenterology
Also Included In: Colorectal Cancer;  Infectious Diseases / Bacteria / Viruses;  Cancer / Oncology
Article Date: 29 Aug 2008 - 1:00 PDT

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Researchers with Vanderbilt-Ingram Cancer Center have discovered one of the clues that may explain how a common stomach bacteria 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.

Daniel P. O'Brien, Ph.D. was lead author on the paper. Other researchers include Judith Romero-Gallo, B.A., Barbara G. Schneider, Ph.D., Rupesh Chaturvedi, Ph.D., Alberto Delgado, B.A., Elizabeth J. Harris, M.D., Uma Krishna, B.A., Seth R. Ogden, B.A., Dawn A. Israel, Ph.D. and Keith T. Wilson, M.D.

The research was supported by the National Institutes of Health, the Vanderbilt Digestive Diseases Research Center and the Office of Medical Research, Department of Veterans Affairs.

The Vanderbilt-Ingram Cancer Center is a National Cancer Institute Comprehensive Cancer Center, one of two centers in Tennessee and 41 in the country to earn this highest distinction. Its nearly 300 faculty members generate more than $140 million in annual federal research funding, ranking it among the top 10 centers in the country in competitive grant support, and its clinical program sees approximately 4,000 new cancer patients each year. Vanderbilt-Ingram, based in Nashville, Tenn., recently joined with 21 of the world's leading centers in the National Comprehensive Cancer Network, a non-profit alliance dedicated to improving cancer care for patients everywhere.

Vanderbilt-Ingram Cancer Center