Analysis of chronic inflammatory lesions of the colon for BMMF Rep antigen expression and CD68 macrophage interactions.

Consumption of Eurasian bovine meat and milk has been associated with cancer development, in particular with colorectal cancer (CRC). In addition, zoonotic infectious agents from bovine products were proposed to cause colon cancer (zur Hausen et al., 2009). Bovine meat and milk factors (BMMF) are small episomal DNA molecules frequently isolated from bovine sera and milk products, and recently, also from colon cancer (de Villiers et al., 2019). BMMF are bioactive in human cells and were proposed to induce chronic inflammation in precancerous tissue leading to increased radical formation: for example, reactive oxygen and reactive nitrogen species and elevated levels of DNA mutations in replicating cells, such as cancer progenitor cells (zur Hausen et al., 2018). Mouse monoclonal antibodies against the replication (Rep) protein of H1MSB.1 (BMMF1) were used to analyze BMMF presence in different cohorts of CRC peritumor and tumor tissues and cancer-free individuals by immunohistochemistry and Western blot. BMMF DNA was isolated by laser microdissection from immunohistochemistry-positive tissue regions. We found BMMF Rep protein present specifically in close vicinity of CD68+ macrophages in the interstitial lamina propria adjacent to CRC tissues, suggesting the presence of local chronic inflammation. BMMF1 (modified H1MSB.1) DNA was isolated from the same tissue regions. Rep and CD68+ detection increased significantly in peritumor cancer tissues when compared to tissues of cancer-free individuals. This strengthens previous postulations that BMMF function as indirect carcinogens by inducing chronic inflammation and DNA damage in replicating cells, which represent progress to progenitor cells for adenoma (polyps) formation and cancer.

Structural expression of bovine milk and meat factors in tissues of colorectal, lung and pancreatic cancer patients.

Chronic inflammation, linked to the presence of bovine milk and meat factors (BMMFs) and specific subsets of macrophages, results in oxygen radical synthesis and induction of mutations in DNA of actively replicating cells and replicating single stranded DNA. Cancers arising from this process have been characterized as indirect carcinogenesis by infectious agents (without persistence of genes of the agent in premalignant or cancers cells). Here, we investigate structural properties of pleomorphic vesicles, regularly identified by staining peritumor tissues of colorectal, lung and pancreatic cancer for expression of BMMF Rep. The latter represents a subgroup of BMMF1 proteins involved in replication of small single-stranded circular plasmids of BMMF, but most likely also contributing to pleomorphic vesicular structures found in the periphery of colorectal, lung and pancreatic cancers. Structurally dense regions are demonstrated in preselected areas of colorectal cancer, after staining with monoclonal antibodies against BMMF1 Rep. Similar structures were observed in human embryonic cells (HEK293TT) overexpressing Rep. These data suggest that Rep or Rep isoforms contribute to the structural formation of vesicles.

Infectious Agents in Bovine Red Meat and Milk and Their Potential Role in Cancer and Other Chronic Diseases.

Red meat and dairy products have frequently been suggested to represent risk factors for certain cancers, chronic neurodegenerative diseases, and autoimmune and cardiovascular disorders. This review summarizes the evidence and investigates the possible involvement of infectious factors in these diseases. The isolation of small circular single-stranded DNA molecules from serum and dairy products of Eurasian Aurochs (Bos taurus)-derived cattle, obviously persisting as episomes in infected cells, provides the basis for further investigations. Gene expression of these agents in human cells has been demonstrated, and frequent infection of humans is implicated by the detection of antibodies in a high percentage of healthy individuals. Epidemiological observations suggest their relationship to the development multiple sclerosis, to heterophile antibodies, and to N-glycolylneuraminic acid (Neu5Gc) containing cell surface receptors.

Dairy cattle serum and milk factors contributing to the risk of colon and breast cancers.

The analysis of published epidemiological data on colon and breast cancer reveals a remarkable concordance for most regions of the world. A low incidence for both cancers has been recorded in Mongolia and Bolivia. Discrepant data, however, have been reported for India, Japan and Korea. In India, the incidence of breast cancer is significantly higher than for colon cancer, in Japan and Korea colon cancer exceeds by far the rate of breast cancer. Here, studies are summarized pointing to a species-specific risk for colon cancer after consumption of beef originating from dairy cattle. Uptake of dairy products of Bos taurus-derived milk cattle, particularly consumed at early age, is suggested to represent one of the main risk factors for the development of breast cancer. A recent demonstration of reduced breast cancer rates in individuals with lactose intolerance (Ji et al., Br J Cancer 2014; 112:149-52) seems to be in line with this interpretation. Species-specific risk factors for these cancers are compatible with the transmission of different infectious factors transferred via meat or dairy products. Countries with discordant rates of colon and breast cancer reveal a similar discordance between meat and milk product consumption of dairy cattle. The recent isolation of a larger number of novel presumably viral DNAs from serum, meat and dairy products of healthy dairy cows, at least part of them infectious for human cells, deserves further investigation. Systemic infections early in life, resulting in latency and prevention of subsequent infections with the same agent by neutralizing antibodies, would require reconsideration of ongoing prospective studies conducted in the adult population.

Papillomaviruses and cancer: from basic studies to clinical application.

Links between human papillomaviruses (HPVs) and cervical cancer were first suspected almost 30 years ago. DNA of specific HPV types has since been found in almost all cervical cancer biopsies. HPV oncogenes that are expressed in these cells are involved in their transformation and immortalization, and are required for the progression towards malignancy. Epidemiological studies have underlined that HPVs are the main aetiological factor for cervical cancer. But how has this knowledge been translated into the clinic to allow the prevention, screening and treatment of cervical cancer?

Red meat consumption and cancer: reasons to suspect involvement of bovine infectious factors in colorectal cancer.

An increased risk for colorectal cancer has been consistently reported for long-time consumption of cooked and processed red meat. This has frequently been attributed to chemical carcinogens arising during the cooking process of meat. Long-time fish or poultry consumption apparently does not increase the risk, although similar or higher concentrations of chemical carcinogens were recorded in their preparation for consumption. The geographic epidemiology of colorectal cancer seems to correspond to regions with a high rate of beef consumption. Countries with a virtual absence of beef in the diet (India) or where preferably lamb or goat meat is consumed (several Arabic countries) reveal low rates of colorectal cancer. In China, pork consumption has a long tradition, with an intermediate colorectal cancer rate. In Japan and Korea, large scale beef and pork imports started after World War II or after the Korean War. A steep rise in colorectal cancer incidence was noted after 1970 in Japan and 1990 in Korea. The consumption of undercooked beef (e.g., shabu-shabu, Korean yukhoe and Japanese yukke) became very popular in both countries. The available data are compatible with the interpretation that a specific beef factor, suspected to be one or more thermoresistant potentially oncogenic bovine viruses (e.g., polyoma-, papilloma- or possibly single-stranded DNA viruses) may contaminate beef preparations and lead to latent infections in the colorectal tract. Preceding, concomitant or subsequent exposure to chemical carcinogens arising during cooking procedures should result in increased risk for colorectal cancer synergistic with these infections.

Bovine Meat and Milk Factors (BMMFs): Their Proposed Role in Common Human Cancers and Type 2 Diabetes Mellitus.

Exemplified by infections with bovine meat and milk factors (BMMFs), this manuscript emphasizes the different mechanistic aspects of infectious agents contributing to human cancers by "direct" or "indirect" interactions. The epidemiology of cancers linked to direct carcinogens (e.g., response to immunosuppression) differs from those cancers linked with indirect infectious interactions. Cancers induced by direct infectious carcinogens commonly increase under immunosuppression, whereas the cancer risk by indirect carcinogens is reduced. This influences their responses to preventive and therapeutic interferences. In addition, we discuss their role in colon, breast and prostate cancers and type II diabetes mellitus. A brief discussion covers the potential role of BMMF infections in acute myeloid leukemia.

Childhood leukemias and other hematopoietic malignancies: interdependence between an infectious event and chromosomal modifications.

A large number of epidemiological observations suggest an infectious origin of hematopoietic malignancies, including various forms of leukemia, nonHodgkin's lymphomas, Hodgkin's lymphomas and multiple myelomas. Incidence of nonHodgkin's lymphomas and Hodgkin's lymphomas, although not of leukemias, is substantially increased under immunosuppression. Specific chromosomal modifications (translocations) resulting in fusion genes frequently emerge as early, but not sufficient, events for malignant progression in most of these conditions. Presently less than 10% of the global incidence of leukemias and lymphomas can be linked to infections (Epstein-Barr virus, human T-lymphotropic retrovirus, human herpesvirus type 8 and Helicobacter pylori). For individual tumor types of the remaining more than 90%, several risk factors have been identified. They include occupational hazards, such as engagement in community services and agriculture, as well as time-space clustering. In childhood leukemias, a protective effect was noted for multiple infections during the first year of life and for at least 6 months of breastfeeding. A high socioeconomic state and absence of multiple contacts during the early phase of life have been described as risk factors. A hypothesis is presented here which combines these observations. It postulates a wide-spread viral infection, nontumorigenic when replication competent, but potentially leukemiogenic or carcinogenic when replication-incompetent viral genomes infect cells with specific chromosomal modifications. Existing data on polyoma-like virus types seem to render members of this or structurally related virus families as putative candidates for these malignancies.

The search for infectious causes of human cancers: where and why (Nobel lecture).

Slightly more than 20% of the global cancer burden can currently be linked to infectious agents, including viruses, bacteria, and parasites. In this Review the reasons for their relatively late discovery are analyzed, and epidemiological observations that may point to an involvement of additional infectious agents in specific human cancers are highlighted. Emphasis is placed on hematopoietic malignancies, breast and colorectal cancers, as well as basal cell carcinomas of the skin and lung cancers in nonsmokers.

Cancers in Humans: A Lifelong Search for Contributions of Infectious Agents, Autobiographic Notes.

This review briefly covers periods of my early life; experiences during World War II; my school education; and my period as a medical student in Bonn, Hamburg, and Düsseldorf. Mainly emphasized is my scientific career after finishing my medical internship and periods as a postdoc at the Institute for Microbiology in Düsseldorf and the Virus Laboratories of the Children's Hospital of Philadelphia and as Senior Research Fellow at the Institute of Virology in Würzburg, Germany. Subsequent appointment as chairman of the newly established Institute of Virology, University of Erlangen-Nürnberg, in a similar position at the University of Freiburg, and then for 20 years as scientific director of the Deutsches Krebsforschungszentrum, Heidelberg, are discussed, covering the scientific developments during these periods. The emeritus period since 2003 was particularly exciting, leading to the discovery of autonomously replicating plasmids, derived from specific bacteria, and their link to common human cancers (colon, breast, and prostate).

Structural analysis of a replication protein encoded by a plasmid isolated from a multiple sclerosis patient.

Bovine meat and milk factors (BMMFs) are circular, single-stranded episomal DNAs that have been detected in bovine meat and milk products. BMMFs are thought to have roles in human malignant and degenerative diseases. BMMFs encode a replication initiator protein (Rep) that is actively transcribed and translated in human cells. In this study, a Rep WH1 domain encoded on a BMMF (MSBI1.176) isolated from a multiple sclerosis human brain sample was determined to 1.53 Šresolution using X-ray crystallography. The overall structure of the MSBI1.176 WH1 domain was remarkably similar to other Rep structures, despite having a low (28%) amino-acid sequence identity. The MSBI1.176 WH1 domain contained elements common to other Reps, including five α-helices, five ß-strands and a hydrophobic pocket. These new findings suggest that the MSBI1.176 Rep might have comparable roles and functions to other known Reps of different origins.

A specific class of infectious agents isolated from bovine serum and dairy products and peritumoral colon cancer tissue.

The in silico analyses of 109 replication-competent genomic DNA sequences isolated from cow milk and its products (97 in the bovine meat and milk factors 2 group - BMMF2, and additional 4 in BMMF1) seems to place these in a specific class of infectious agents spanning between bacterial plasmid and circular ssDNA viruses. Satellite-type small plasmids with partial homology to larger genomes, were also isolated in both groups. A member of the BMMF1 group H1MBS.1 was recovered in a distinctly modified form from colon tissue by laser microdissection. Although the evolutionary origin is unknown, it draws the attention to the existence of a hitherto unrecognized, broad spectrum of potential pathogens. Indirect hints to the origin and structure of our isolates, as well as to their replicative behaviour, result from parallels drawn to the Hepatitis deltavirus genome structure and replication.

Novel human polyomaviruses--re-emergence of a well known virus family as possible human carcinogens.

Polyomaviruses belong to a family of DNA tumor viruses that frequently cause cancer upon inoculation into heterologous hosts. The rhesus monkey virus SV40 and mouse polyomavirus have been studied in particular detail. Two members of the polyomavirus family, BK and JC viruses, were identified as human pathogens more than 30 years ago. Both are oncogenic when inoculated into newborn rodents. Their possible role in human cancers has been intensively investigated; conclusive results are, however, still missing. During the past year 3 new members of the polyomavirus family have been identified in humans, KI, WU, and MC-Polyomavirus. Whereas the first 2 were only found in respiratory fluids of children with respiratory infections and in healthy individuals, the third virus was found to be specifically linked to Merkel tumors, a rare human cancer of neuroendocrine origin. The positive Merkel cells contain viral DNA in an integrated and clonal form, suggesting an involvement of this virus in the etiology of those tumors. This article will summarize the results of recent polyomavirus isolations from humans and animals and also address the potential role of members of this virus family in other human malignancies. It also makes reference to observations of polyomavirus-like particles in other conditions, particularly in hair-follicle cell-related proliferations.

European Academy of Cancer Sciences - position paper.

The European Academy of Cancer Sciences (EACS) is an independent advisory body of well-recognised medical specialists and researchers striving to create a compelling interactive continuum of cancer research, from innovative basic research to implementation of state-of-the-art evidence-based cancer care and prevention. Achieving the above will entail bridging high-quality basic and preclinical cancer research to research on prevention, early detection and therapeutics as well as improving coordination of translational research efforts across Europe. The latter is expected to be expedited through quality assuring translational cancer research in Comprehensive Cancer Centres - entities that link research with the healthcare system - and networks of cancer research centres. Achieving a critical mass of expertise, resources and patients is crucial. Improving late translational research, which involves clinical studies to assess effectiveness, and added value for the health care is also a high priority. Both high-quality Big Data collections and the intelligent use of these data will promote innovation in cancer research and support outcomes research to assess clinical utility, quality of cancer care and long-term follow-up of treated patients. The EACS supports the mission-oriented approach recently proposed by the European Commission in Horizon Europe to deal with major challenges and would like to persuade the EU and its member states to formally launch a mission in cancer to boost and streamline the cancer research continuum in Europe. Building a coherent translational cancer research continuum with a focus on patients and individuals at risk will require, however, foresight as well as the extensive and continuous provision of evidence-based advice to inform policy.

Isolation of Two Virus-Like Circular DNAs from Commercially Available Milk Samples.

Epidemiological data indicate a potential relationship between milk and dairy product consumption and the incidence of breast cancer, as well as neurodegenerative diseases. We report the isolation of two novel circular DNA molecules isolated from commercially available milk.