Helicobacter pylori cause stomach cancer

Helicobacter pylori cause stomach cancer

06/09/2011

The gastric bacterium Helicobacter pylori can not only cause gastritis and gastric ulcer but is a significant risk factor for the development of gastric cancer (gastric cancer). Anne Müller and Massimo Lopes from the Institute of Molecular Cancer Research at the University of Zurich have now uncovered for the first time the mechanism by which Helicobacter pylori bacteria damage human host cells and thus promote the onset of gastric cancer.

Like the Swiss researchers in the current issue of the specialist magazine „Proceedings of the National Academy of Sciences“ (PNAS), stomach cancer is one of the most common cancers worldwide. Thus, more than one-third of cancer deaths are due to carcinoma in the stomach. Prior to the current study by Anne Müller and Massimo Lopes, chronic gastric mucosal infections with Helicobacter pylori bacteria were already known to be major risk factors for the development of gastric cancer. For the first time, however, the Swiss researchers succeeded in deciphering the molecular mechanism that leads to the onset of gastric cancer.

Damage to DNA by Helicobacter pylori infections
In studying the genetic consequences of Helicobacter pylori infection, the researchers around Anne Müller and Massimo Lopes have found that the bacteria in the cells of the gastric mucosa cause breaks in both strands of the DNA molecule. According to the scientists, this damages the genetic information of the cell and promotes tissue mutations that cause gastric cancer in uncontrolled cell growth. According to the researchers, the occurrence of double-strand breaks is dependent on the intensity and duration of the Helicobacter pylori infection. When the pathogens were killed by antibiotics within a few hours after infection, the natural repair mechanisms were able to correct most fractures and prevent uncontrolled cell growth, according to the experts.

In the absence of drug treatment for gastric mucosal infection, natural repair mechanisms were unable to control the growing number of double-strand breaks in the long term, according to the Swiss researchers. The fractures would only be repaired inaccurately or not at all, according to the statement of Anne Müller and colleagues. As a consequence, the experts, in addition to the death of cells, cite a growing number of genetic mutations that significantly increase the risk of gastric cancer. Thus, the relationship between the gastric bacterium Helicobacter pylori and the onset of gastric cancer is clearly scientifically proven for the first time, emphasize Anne Müller and Massimo Lopes. The current study results also show, according to the researchers, the importance of early treatment for Helicobacter pylori gastric mucosal infections. In addition, based on the current findings, not only the gastric cancer therapy but possibly also the early detection of gastric carcinoma could be significantly improved in the future, according to the hope of the Swiss scientists.

Signs of Helicobacter pylori infection are serious
Conventional treatment of infection with the first documented in 1983 stomach bacterium Helicobacter pylori is usually based on the administration of special antibiotics in combination with an active ingredient to reduce acid production in the stomach. Often, an infection with Helicobacter pylori is, however, without symptoms, so that those affected see no reason to see a doctor. According to the experts, possible signs of Helicobacter pylori infection may be abdominal pain in the upper abdomen, stomach depressions, flatulence, heartburn, diarrhea or nausea and vomiting. In view of the increased gastric cancer risk associated with Helicobacter pylori infection, a doctor should be urgently consulted if so suspected. (Fp)

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Image: Sebastian Karkus