Share:
Studies Helicobacter infections cause gastric cancer
Bacteria of the genus Helicobacter pylori are to be evaluated as a potential trigger for gastric cancer. In a recent study, scientists from the Berlin Charité showed how infections with the bacterium can be responsible for the development of gastric cancer.
Scientists have recently discovered the mechanisms by which Helicobacter pylori infections contribute to the development of gastritis. Now, researchers from the Charité - Universitätsmedizin Berlin have also been able to prove that Helicobacter pylori infections can cause stomach cancer. The scientists published their results in the journal "Nature".
Helicobacter pylori infections can cause stomach cancer. (Image: fotoliaxrender / fotolia.com) Increased cell division in infected tissue
Infection with the stomach bacterium Helicobacter pylori are widespread, according to notification of the Charité and they are considered the most important risk factor for the development of gastric cancer. However, it remains unclear how Helicobacter infections increase the risk of gastric cancer. "After infection, there is an increased cell division in the infected tissue due to a hitherto unknown mechanism," explain the scientists. The research team around Dr. Michael Sigal and Prof. dr. Thomas F. Meyer, Director at the Max Planck Institute for Infection Biology, was the first to decode this process.
Related to accelerated stem cell regeneration in the gastric glands
It was already known that the glands in the stomach have a particularly high regenerative capacity and are completely replaced every one to two weeks. The question remained as to how a bacterial infection under these circumstances can lead to long-term changes. In cooperation with scientists from the Max Planck Institute for Infection Biology in Berlin and the Stanford School of Medicine in California, the research team was able to Michael Sigal of the Medical Clinic with a focus on hepatology and gastroenterology at the Berlin Charité now shows how "a Helicobacter infection can be responsible for the development of gastric cancer." For the first time in the current study there is a direct correlation between the infection and an accelerated one Stem cell regeneration has been produced within the gastric glands.
More cells with stem cell potential
According to the researchers, the number of cells with stem cell potential increases under the influence of the bacterium and with them the risk of a pathological change. "At the base of the glands there are long-lived stem cells that are constantly generating new cells," explains Dr. med. Sigal. The aim of the study was to determine their identity and also the processes that control their regeneration. For this purpose, among other things, the stem cells of the stomach were examined in an animal model, whereby by means of sensitive new techniques molecules in the stomach tissue could be displayed in high resolution. For example, "it was possible to image the molecules that regulate the stem cells and show their spatial proximity to the stem cell area," reports the Charité.
Certain enzyme significantly influences the function of the stem cells
The researchers also used a model of Helicobacter pylori infection that mimics the first precursors of cancer development in humans and conducted experiments by means of so-called organoid (cell cultures from human and animal stem cells obtained directly from the stomach tissue) through. The characterization of stem cells has shown that there are two different types of stem cells in the stomach. Both are positive for the marker Axin2. In addition, the scientists have "found out that the cells, which are located directly below the glands, produce a specific molecule called R-spondin 3." This significantly affect the function of the stem cells and activate cell division in a subpopulation of stem cells, whereby the regeneration speed of the gastric glands is increased.
Bacteria as a cause of cancer so far underestimated
According to the researchers, Helicobacter pylori infection causes R-spondin production to increase and increase stem cell activity, suggesting that long-term increased stem cell division directly favors cancer development. While it has long been known that certain viruses can cause cancer by introducing genes into the host cell, bacteria have only recently been studied as potential causes of cancer. The underlying mechanisms are less clear. "Now the teams around Dr. Sigal and Prof. Meyer, in cooperation with other cooperation partners, overcome the hitherto prevailing dogma that bacterial infections only affect cells on the surface, "according to the Charité.
Basis for the development of new treatment approaches?
"Helicobacter pylori causes a lifelong infection and increases the number of long-lived cells with stem cell potential in the glands of the stomach," Dr. Sigal. The speed of stem cell division is increased, which ultimately leads to pathological changes in the epithelium. The current study provides a better insight into the mechanisms that can trigger gastric cancer and also provides "more general evidence of how chronic bacterial infections disrupt tissue function and thus increase the risk of cancer," adds Prof. Meyer. In the long term, current evidence may also help to advance the development of improved treatment approaches, researchers hope. (Fp)