Eleven virus species favor cancer – naturopathy & naturopathic specialist portal

How widespread pathogens increase the risk of cancer

A large international study with the lead participation of the German Cancer Research Center found for the first time solid evidence that eleven widespread viruses increase the risk of cancer. Every seventh tumor is said to be associated with an infection.

An international research team led by the German Cancer Research Center (DKFZ) has carried out the first comprehensive study, which underpins the involvement of various widespread pathogens in the development of cancer. At least eleven viruses, including human papillomaviruses (HPV), some hepatitis viruses and the Epstein-Barr virus, were found to be linked between the infection and cancer. The results were recently published in the renowned journal “Nature Genetics”.

Helicobacter pylori favors stomach cancer

Links between certain infectious diseases and the development of cancer have long been known. “We already knew of some strong links between infection and cancer,” reports Dr. Daniel Brewer from the study team. For example, the presence of Helicobacter pylori in the digestive tract can lead to stomach ulcers, which in turn are associated with an increased risk of stomach cancer.

Every seventh tumor is favored by viruses

The international research team, consisting of over 1,300 scientists, now systematically searched the DNA of over 2,600 tumor samples from 38 different types of cancer for connections between common pathogens and tumor formation. They found what they were looking for in eleven pathogens. Overall, the team found a connection to infections in more than every seventh tumor.

Which viruses are often involved in cancer?

The researchers found the genetic material of Epstein-Barr viruses (EBV) in 5.5 percent of the examined tumor samples. These viruses have been linked to numerous types of cancer, particularly lymphomas and cancer of the stomach and nasopharynx. The study also found a link between liver cancer and hepatitis B viruses. Hepatitis B DNA was found in 62 of the 330 liver cancer samples examined.

HPV 16 is closely related to cervical cancer. The researchers found the DNA of human papilloma viruses in 19 out of 20 cancer cases. In addition, HP viruses also seem to favor throat / throat tumors. Here, too, their DNA was discovered in 18 of 57 cases. In addition, the already known connection between retroviruses and kidney carcinomas and between cytomegaloviruses and gastric cancer was confirmed.

Not all viruses promote cancer

Through the analysis, the researchers were able to rule out with some probability that they are involved in the development of cancer. For example, no involvement in cancer was found in adenoviruses (“eye flu”) or in baculoviruses.

Why do some viruses favor cancer?

The researchers also deciphered some of the mechanisms that viruses use to trigger carcinogenic mutations. The team found that some viruses incorporate their genes into the human genome, causing virus-related mutations. This process was observed particularly strongly in hepatitis B and papilloma viruses.

“We often observed, for example, the incorporation of HPV DNA into the so-called telomerase promoter,” explains study author Marc Zapatka. This genetic switching element controls the production of the so-called “immortality enzyme” telomerase. This enzyme is particularly often mutated in many cancers. “We have now shown that virus integration can also activate this gene switch and thus give cells immortality,” emphasizes Zapatka.

Another mechanism discovered

In addition to incorporating the genome, the researchers were able to uncover another mechanism: the cell’s own virus defense. The cell tries to protect itself from the virus DNA with so-called APOBEC proteins. This defense often causes mutations in the cell’s genome. This mechanism has been observed particularly in cervical cancer and neck / throat tumors after HPV infections.

No strangers discovered

Overall, the researchers come to the conclusion that significantly more tumors contain traces of viruses than previously thought. “Nevertheless, we were unable to confirm the frequently voiced assumption that other, previously unknown viruses are associated with cancer,” concludes study director Peter Lichter. “In many cases, however, we can now see more clearly how the pathogens cause cells to malignant.” (Vb)