Scientists have uncovered how certain E. coli bacteria in the gut promote colon cancer by binding to intestinal cells and releasing a DNA-damaging toxin. The study, published in Nature , sheds light on a new approach to potentially reduce cancer risk.
The study was performed by the teams of Prof. Lars Vereecke (VIB-UGent Center for Inflammation Research) and Prof. Han Remaut (VIB-VUB Center for Structural Biology).
Bacteria and colon cancer Colon cancer ranks as the third most prevalent and deadliest type of cancer. Alarmingly, its incidence is rising, particularly among young people. Emerging evidence indicates that certain bacteria in the gut microbiota (the collection of primarily healthy bacteria in our intestines) can promote the development of colon cancer, through largely unknown mechanisms.
One of the suspected cancer-promoting bacteria is pks+ E. coli , which produces a genotoxin called 'colibactin'. Colibactin is capable of binding and damaging human DNA, causing mutations that can increase the risk of cancer.
These bacteria and the mutations they induce are remarkably overabundant in patients with colon cancer. Until now, it was unclear how pks+ E. coli could reach and damage the gut wall to promote cancer development.
The experiments by the teams of Prof. Lars Vereecke (VIB-UGent) and Prof. Han Remaut (VIB-VUB) revealed that these bacteria switch between a free-swimming state and a mode where they attach to the gut tissue lining (the intestinal epithelium).
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