Going from ulcers to cancer

August 22, 2008

Researchers have uncovered a big clue as to why some of the bacteria that cause stomach ulcers pose a greater risk for serious problems like stomach cancer than others; it turns out these bacteria can exploit the surrounding stomach cells to protect them from the immune system.

Helicobacter pylori is a bacterial strain that 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 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 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 use the DAF receptor on the host cell they're attached to like a bodyguard to protect them from the immune system. Peek and colleagues also note 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.

Source: American Society for Biochemistry and Molecular Biology

Explore further: Loss of tight junction protein promotes development of precancerous cells

Related Stories

Loss of tight junction protein promotes development of precancerous cells

December 13, 2018
Tight junctions are multi-protein complexes that serve as barriers in epithelial tissues such as the skin or lining of the gut. Loss of a specific tight junction barrier protein, claudin 18, occurs in the majority of gastric ...

Ulcer-causing bacteria tamed by defect in cell-targeting ability

November 21, 2011
Without the ability to swim to their targets in the stomach, ulcer-causing bacteria do not cause the inflammation of the stomach lining that leads to ulcers and stomach cancer, according to a new study by researchers at the ...

Other stomach microbiota modulate resistance to H. pylori-driven ulcers

March 25, 2013
Mice with different naturally occurring stomach bacteria have distinct susceptibilities to disease caused by Helicobacter pylori, the well-known cause of ulcers in humans, according to a study published online ahead of print ...

Ulcer-causing bacteria induces stomach stem cell growth in mice, researchers find

May 6, 2015
The ulcer-causing bacterium Helicobacter pylori can directly interact with stomach stem cells, causing the cells to divide more rapidly, according to a new study by researchers at the Stanford University School of Medicine.

Are stem cells the link between bacteria and cancer?

August 17, 2017
Gastric carcinoma is one of the most common causes of cancer-related deaths, primarily because most patients present at an advanced stage of the disease. The main cause of this cancer is the bacterium Helicobacter pylori, ...

AIDS patients face risk for esophageal, stomach cancers

September 24, 2012
People with AIDS are at increased risk for developing esophageal and stomach carcinoma as well as non-Hodgkin lymphomas (NHLs), according to a new study in Gastroenterology, the official journal of the American Gastroenterological ...

Recommended for you

Folate deficiency creates hitherto unknown problems in connection with cell division

December 17, 2018
Folate deficiency creates more problems in connection with DNA replication than researchers had hitherto assumed, researchers from the University of Copenhagen show in a new study. Once a person lacks folate, the damage caused ...

Babies and toddlers at greater risk from second-hand smoke than previously thought, study finds

December 16, 2018
Infants and toddlers in low-income communities may be even more at risk from second- and third-hand smoke exposure than has been believed, according to new federally supported research.

A co-worker's rudeness can affect your sleep—and your partner's, study finds

December 14, 2018
Rudeness. Sarcastic comments. Demeaning language. Interrupting or talking over someone in a meeting. Workplace incivilities such as these are becoming increasingly common, and a new study from Portland State University and ...

A holiday gift to primary care doctors: Proof of their time crunch

December 14, 2018
The average primary care doctor needs to work six more hours a day than they already do, in order to make sure their patients get all the preventive and early-detection care they want and deserve, a new study finds.

Teens get more sleep with later school start time, researchers find

December 12, 2018
When Seattle Public Schools announced that it would reorganize school start times across the district for the fall of 2016, the massive undertaking took more than a year to deploy. Elementary schools started earlier, while ...

Large restaurant portions a global problem, study finds

December 12, 2018
A new multi-country study finds that large, high-calorie portion sizes in fast food and full service restaurants is not a problem unique to the United States. An international team of researchers found that 94 percent of ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.