Consumption of beef and milk linked to cancer
More than a decade ago, Nobel laureate Harald Zur Hausen discovered, based on big data, that beef and milk intake was linked to the development of cancer, particularly colorectal cancer.
A few years ago, a research team led by De Villiers of the German Cancer Research Centre discovered a new pathogen in dairy products and bovine serum. Since they come from beef and milk, the team called them BMMF (bovine mutton and milk factor).
Does the new infectious agent BMMF found in dairy products and bovine serum play an important role in developing colorectal cancer? To clarify this question, Zul Hausen and De Villiers collaborated.
The team discovered BMMF (bovine and dairy factor) in cells near the tumours of colon cancer patients and then found that BMMF causes local chronic inflammation, leading to an increase in reactive oxygen species (ROS), triggering mutations that subsequently promote the development and progression of long-term cancer.
The research team investigated this issue in detail using tissue samples from colon cancer and healthy intestines. The team used antibodies against the Rep protein and tested for BMMF in 15 of 16 colon cancer tissue samples.
The team was surprised to find that the test showed that it was not the cancer cells themselves that contained the Rep protein, but rather the cells in the vicinity of the tumour that contained the Rep protein. The presence of Rep proteins has been detected in the lamina propria, particularly near the intestinal crypts, the connective tissue located under the intestinal mucosa.
The team also succeeded in isolating BMMF DNA from Rep-positive cells closely related to the pathogen isolated from the milk samples.
Does BMMF cause chronic inflammation?
The team speculates that the presence of BMMF may trigger a chronic inflammatory process in the intestinal tissues. One of the symptoms of inflammation in the presence of pro-inflammatory macrophages in the vicinity of the inflammation. The team also found a high level of reactive oxygen species (ROS) was detected in the Rep-positive cell environment. An increase in reactive oxygen species would favour the development and progression of genetic mutations, which are important factors in cancer formation.
Are these inflammatory conditions linked to cancer?
The team found that these inflammations are particularly confined to the intestinal crypts containing intestinal stem cells. These stem cells are responsible for the continuous regeneration of the intestinal mucosa. The intestinal stem cells continuously produce many progenitor cells that divide rapidly and are promoted to mutate into inflammation. The more mutations that accumulate, the greater the risk of genes causing uncontrolled cell division and growth.
Is BMMF an indirect carcinogen?
Zur Hausen believes that beef and milk BMMF should be considered an indirect carcinogen, given these findings. It can act on dividing cells in the intestinal mucosa for decades. It can promote chronic inflammation and promote Carcinogenic genetic mutations.
Bund T, Nikitina E, Chakraborty D, Ernst C, Gunst K, Boneva B, Tessmer C, Volk N, Brobeil A, Weber A, Heikenwalder M, Zur Hausen H, de Villiers EM. Analysis of chronic inflammatory lesions of the colon for BMMF Rep antigen expression and CD68 macrophage interactions. Proc Natl Acad Sci U S A. 2021 Mar 23;118(12):e2025830118. doi: 10.1073/pnas.2025830118. PMID: 33723077.