Stem Cell

Are stem cells the link between bacteria and cancer?

Are stem cells the link between bacteria and cancer?
Cross section of stomach glands, showing the outline of individual cells in green and their nuclei in blue. Credit: MPI for Infection Biology

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, which chronically infects around half of all humans. However, unlike tumour viruses, bacteria do not deposit transforming genes in their host cells and how they are able to cause cancer has so far remained a mystery. An interdisciplinary research team at the Max Planck Institute in Berlin in collaboration with researchers in Stanford, California, has now discovered that the bacterium sends stem cell renewal in the stomach into overdrive – and stem cell turnover has been suspected by many scientists to play a role in the development of cancer. By showing that the stomach contains two different stem cell types, which respond differently to the same driver signal, they have uncovered a new mechanism of tissue plasticity. It allows tuning tissue renewal in response to bacterial infection.

While it has long been recognized that certain viruses can cause cancer by inserting oncogenes into the host cell DNA, the fact that some bacteria can also cause cancer has been slower to emerge and much harder to prove. While it is now clear that most cases of stomach cancer are linked to chronic infections with H. pylori, the mechanism remains unknown.

Thomas F. Meyer and his colleagues at the Max Planck Institute for Infection Biology in…