The pks+ chromosome sequence found in the bacterium Escherichia coli (E.coli) appears to contribute to the development of colorectal cancer. In particular, there would be a link between mutations associated with its presence and alterations in certain genes that are characteristic of this type of cancer. This discovery could open up innovative possibilities for preventive strategies and personalised therapies, particularly in view of the increasing incidence of colorectal cancer, especially in young adults.
This is the conclusion of a study entitled "Contribution of pks+ E.coli mutations to colorectal carcinogenesis", which has just been published in Nature Communications and was carried out thanks to the collaboration between The Institute of Cancer Research (London), Human Technopole and the University of Milan-Bicocca. The research team was led by Bingjie Chen (London), Daniele Ramazzotti (Milano-Bicocca), Trevor A. Graham (London) and Andrea Sottoriva (Human Technopole).
The research focused on the development of colorectal cancer by analysing the role of the bacterium Escherichia coli (E. coli) in tumour formation. Some strains of Escherichia coli contain an enzyme called polyketide synthetase (E. coli pks+), which codes for the molecule colibactin, a DNA-toxic compound. In particular, the study found that mutations associated with the presence of E. coli pks+ correlated with specific alterations in some key colorectal cancer genes.
Analyses of the genome of healthy mucosa from cancer patients also revealed distinctive mutational signatures consistent with the genotoxic effect of the bacterium. This phenomenon, which has been little studied in the normal mucosa of cancer patients, is emerging as a potential initiator of mutations that contribute to the development of colorectal cancer.
"These results show how E. coli pks+ could be a key element in colorectal carcinogenesis. - points out Daniele Ramazzotti, one of the lead authors of the study - This not only offers a new perspective on the complexity of colorectal cancer development, but could also pave the way for the development of new risk biomarkers for this disease. Indeed, a deeper understanding of the relationship between the gut microbiota and tumour formation could offer innovative opportunities for personalised preventive and therapeutic strategies, especially considering the increase in colorectal cancer, especially in young adults.