Study confirms link between inflammation, cancer

Jun 02, 2008

Chronic inflammation of the intestine or stomach can damage DNA, increasing the risk of cancer, MIT scientists have confirmed. The researchers published evidence of the long-suspected link in the June 2 online issue of the Journal of Clinical Investigation (JCI).

In two studies, the researchers found that chronic inflammation accelerated tumor formation in mice lacking the ability to repair DNA damage.

"It's something that was expected but it was never formally proven," said Lisiane Meira, research scientist in MIT's Center for Environmental Health Sciences (CEHS) and lead author of the paper.

The results of this work suggest that people with decreased ability to repair DNA damage might be more susceptible to developing cancer associated with chronic inflammation such as ulcerative colitis, Meira said.

Inflammation caused by infectious agents such as Helicobacter pylori and Hepatitis C is known to increase the risk of stomach and liver cancers, respectively. Researchers have long known that inflammation produces cytokines (immune response chemicals that encourage cell proliferation and suppress cell death), which can lead to cancer.

In addition, it was suspected that another effect of the inflammation pathway could also induce cancer. During the inflammatory response to infection, immune cells such as macrophages and neutrophils release reactive oxygen and nitrogen species that can damage DNA.

Under normal circumstances, the DNA damage induced during an inflammatory response is repaired by DNA repair systems. But, if the DNA repair system is not functioning properly, that damage can induce mutations that can lead to cancer, according to the new study.

Every individual has variations in the effectiveness of their DNA repair systems, which could help doctors figure out which patients are most susceptible to inflammation-induced cancers.

"That variation could influence the susceptibility of individuals and how they are going to respond to a chronic inflammation response," said Leona Samson, senior author of the study and director of the CEHS.

In the JCI study, the researchers induced colon inflammation in the mice by treating them with a chemical compound that creates a condition similar to human colitis. "Lo and behold, the DNA repair deficient mice were more susceptible" to cancer, said Meira.

To show that this is a general phenomenon, the team did a second study, in collaboration with another CEHS member, James Fox, director of the Division of Comparative Medicine at MIT, and one of his students, Chung-Wei Lee. They showed that mice infected with H. pylori, who also lacked the proper DNA repair mechanisms, were more susceptible to pre-cancerous lesions in the stomach.

This study is related to another recent paper published by Fox, which found that treating H. pylori infection early with antibiotics can prevent cancer development. The new study suggests that if H. pylori goes untreated, patients with poorly functioning DNA repair mechanisms would have a greater risk of developing cancer.

Source: Massachusetts Institute of Technology

Explore further: Manipulating key protein in the brain holds potential against obesity and diabetes

add to favorites email to friend print save as pdf

Related Stories

Smart hydrogels deliver medicine on demand

Jan 15, 2014

(Phys.org) —Researchers at the University of Delaware have developed a "smart" hydrogel that can deliver medicine on demand, in response to mechanical force.

Stash of stem cells found in a human parasite

Feb 23, 2013

(Phys.org)—The parasites that cause schistosomiasis, one of the most common parasitic infections in the world, are notoriously long-lived. Researchers have now found stem cells inside the parasite that ...

Scientists tie DNA repair to key cell signaling network

Jun 15, 2012

University of Texas Medical Branch at Galveston researchers have found a surprising connection between a key DNA-repair process and a cellular signaling network linked to aging, heart disease, cancer and other chronic conditions. ...

Study shows how inflammation can lead to cancer

Apr 19, 2011

A new study shows how inflammation can help cause cancer. Chronic inflammation due to infection or to conditions such as chronic inflammatory bowel disease is associated with up to 25 percent of all cancers.

Recommended for you

New technology allows hair to reflect almost any color

10 hours ago

What if you could alter your hair to reflect any color in the spectrum? What if you could use a flatiron to press a pattern into your new hair color? Those are possibilities suggested by researchers from ...

User comments : 0