German researchers were able to identify a natural enemy of cancer cells – and it’s bacteria! According to latest findings presented in the International Journal of Cancer, bacteria trigger infections in solid tumours which in turn activate immune cells. This process disrupts the tumour’s blood vessels causing parts of it to die off. The scientists were able to demonstrate this mechanism in animal tests (International Journal of Cancer, 2015; doi: 10.1002/ijc.29567).
Since the mid-19th century, the medical community has been aware of the positive effects bacterial infections may have on cancer. Up to now, however, it has remained unclear how the bacteria affect cancer patients, and what causes these positive effects. The science portal Scinexx states that: “During trials involving mice, researchers found that the so-called T cells of the immune system are crucial for fighting tumours. The bacteria as such play a far minor role than previously assumed: They merely provide the immune cells with some sort of jump start.”
At least: “As a result, healed mice develop a specific immunity to the tumour cells”, the study’s author, Christian Stern of the Helmholtz Centre for Infection Research (HZI), is quoted as saying. According to Stern, should the same tumour develop again, e.g. by formation of metastases, it will be rejected as well.
Since bacteria, in addition to their positive anticancer effect, also cause infections and diseases, everything depends on striking the right balance. “The perfect bacterium for the treatment of cancer has not been found yet”, Christian Stern writes on the HZI’s website. The article goes on to say: “We just demonstrated, in more detail and for the first time, the contribution the immune system has in bacteria-mediated tumour therapy and showed that an effective immunological memory is formed.” Understanding these processes better may help to use this therapy in humans in the future.