Link between chronic inflammation and cancer confirmed
Scientists at the Massachusetts Institute of Technology, working under the guidance of Dr. Leona Samson, have proved a long-existing, but not officially proven hypothesis. In experiments on mice unable to repair DNA damage, they demonstrated that chronic inflammation contributes to the formation of tumors.
The results of this work indicate that people with a reduced ability to repair DNA damage are more susceptible to the development of malignant diseases associated with chronic inflammatory processes, such as ulcerative colitis.
Inflammation caused by infectious agents such as Helicobacter pylori and hepatitis C is known to increase the risk of stomach and liver cancer, respectively. Scientists have also known for a long time that cytokines are synthesized in the inflammatory focus, stimulating cell proliferation and suppressing their death, which can contribute to the development of cancer.
In addition, it was believed that during the formation of an immune response to infection, immune cells, such as macrophages and neutrophils, release DNA-damaging reactive oxygen species and nitrogen compounds.
Under normal conditions, DNA damage induced during the inflammatory reaction is repaired by specialized proteins. However, if the repair system does not work adequately, DNA damage can lead to mutations and the development of cancer.
As part of the experiment, scientists induced inflammation of the colon in mice by treating the tissue with a special chemical compound. At the same time, a line of mice with a disrupted DNA repair mechanism was significantly more predisposed to the development of cancer.
To confirm the conclusion about the relationship between chronic inflammation and cancer, the researchers conducted a second work in which they infected animals with Helicobacter pylori. As a result, a significantly larger number of precancerous foci formed in the stomachs of mice unable to repair DNA damage.
The results of this work are consistent with the results of an earlier study, according to which the treatment of Helicobacter pylori infection with antibiotics reduces the likelihood of developing stomach cancer. New data indicate that with an untreated infectious process caused by Helicobacter pylori, people with poorly functioning DNA damage repair mechanisms have an increased risk of developing cancer.
Each person has variations in the activity of the DNA damage repair system, which can be used to identify patients most predisposed to the development of inflammation-induced tumors.
Portal "Eternal youth" www.vechnayamolodost.ru based on MIT materials
16.07.2008