PNAs: intestinal microbiological disorder leading to the occurrence of colorectal cancer

November 21, 2019 / BIOON / - recently, a study from the Department of Microbiology of Coll è Ge University in France has shown that imbalance of intestinal flora can promote the onset of colorectal cancer The authors found that transplanting fecal flora of colon cancer patients into mice would cause pathological changes and epigenetic changes in the development of malignant tumors The results were published in the latest PNAs magazine Sporadic colorectal cancer is caused by complex interactions between individuals and their environment In the adverse environment, it can trigger the genetic and epigenetic DNA changes of host cells, thus promoting the onset of sporadic colorectal cancer (image source: www Pixabay Com) previous studies have investigated the role of microbial populations as mediators of these interactions Based on the results of the study in mice, it is suggested that the epigenetic mechanism triggered by some bacteria in the microbiota may contribute to the occurrence or deterioration of sporadic colorectal cancer They then tested their findings in humans In this study, 136 mice were transplanted with fresh feces from nine patients with sporadic colorectal cancer or nine patients without colon disease After that, the authors examined the colon of the mice 7 and 14 weeks after transplantation The number and deterioration of abnormal crypt foci (or ACF, a precancerous lesion type), microbial characteristics and DNA damage of colon were studied They also measured food intake, body weight and blood parameters The association between fecal malnutrition (imbalance of bacterial composition in the gut) and genetic and epigenetic DNA markers in animal tissues has been confirmed by statistical tests In mice that received fresh feces from patients with sporadic colorectal cancer, abnormal crypt foci (ACF) were found, which are considered to be one of the precancerous lesions However, there was no significant genetic change in colon tissue We hope to develop a simple and reusable blood test for the early diagnosis of colorectal cancer in asymptomatic patients This study shows that the microflora of patients with sporadic colorectal cancer can induce precancerous colonic lesions in animals by highly methylation of a few genes Therefore, CMI and / or methylated bacteria can be used as diagnostic markers for this type of cancer Of course, these preliminary findings need to be evaluated and confirmed in clinical trials Sources of information: gutmicrobiota international promotion the onset of chromatical cancer original sources: iradj sobhani, Emma Bergsten, s é verine couffin, AUR é lie Amiot, Biba nebbad, Caroline barau, Nicola de'angelis, Sylvie rabot, Florence canoui poitrine, Denis mestivier, Thierry P é Dron, khashayarsha khazaie, Philippe J Sansonetti Colorectal cancer-associated microbiota contributes to oncogenic epigenetic signatures Proceedings of the National Academy of Sciences, 2019; 201912129 DOI: 10.1073/pnas.1912129116