From correspondents in Washington, United States, 11:31 AM IST

Researchers have gained insights into why some bacteria behind stomach ulcers can also be instrumental in causing abdominal cancers.

A bacterial strain like helicobacter pylori can infect the human stomach and induce inflammation, ulcers, and potentially even stomach cancer.

However, only a small fraction of H. pylori infections ultimately lead to cancer, leading researchers to figure out what biological events will trigger this path.

One type of the H. pylori strain that seems to increase disease risk is the cag+ strain, which contains a set of proteins that allows it to inject bacterial proteins into cells following attachment to the stomach lining. This interaction between bacteria and gastric cells may be a key contributor to chronic damage.

Richard Peek of Vanderbilt-Ingram Cancer Centre and colleagues investigated a cag+ strain in mouse models of H. pylori infection and found that a protein called CagE could induce gastric cells to turn on a receptor called Decay-accelerating factor (DAF).

DAF acts to remove nearby immune proteins that can kill cells to prevent unwanted immune damage.

In essence, the bacteria uses the DAF receptor on the host cell they're attached to like a bodyguard to protect them from the immune system.

Researchers also noted that by continually inducing DAF expression, H. pylori creates an environment of persistent inflammation that can reduce the threshold required for more serious diseases to develop.

(Staff Writer, © IANS)