Lung Cancer Patients Display Increased Expression of Bovine Meat and Milk Factor (BMMF) Proteins in Peritumor Alveolar Macrophages.

Besides smoking and exposure to specific environmental risk factors, also diet and in particular red meat consumption/exposure are described as risk factors contributing to lung cancer development. Incidence of non-smoking associated lung cancer is rising rapidly, globally. Global epidemiology supports an association between lung cancer incidence and consumption of bovine products. The search for meat-/milk-associated cancer risk factors led to the isolation of plasmid DNA termed Bovine Meat and Milk Factors (BMMFs). Due to detection of increased expression levels of a conserved BMMF-encoded protein (Rep) in tissues of colorectal cancer patients, BMMFs have been proposed as causal risk factors for cancer acting via inflammation-driven indirect carcinogenesis. Yet, their presence and possible contribution to lung cancer remained elusive. In this study, Rep expression was quantified in paired tumor/peritumor tissues from lung cancer patients (n = 35) as well as cancer-free individuals (n = 19, tissues adjacent to benign hamartoma) by immunohistochemistry, co-immunofluorescence microscopy, immunodetection/mass spectroscopy and genomics/transcriptomics screening. In all patients tested, Rep expression was immunohistochemically observed in CD68