Crosstalk between mammalian cells and the microbiome through quorum sensing peptides, influencing cancer metastasis

To date, the precise role of the human microbiome in health and disease remains largely unknown. Research mainly focused on the effect of toxins or DNA-damaging reactive oxygen species (ROS), produced by commensal or pathogenic bacteria, on inflammation or carcinogenesis.[1,2] In this study however, we demonstrate that quorum sensing peptides, secreted by intestinal bacteria, can also influence cancer cell behaviour: Phr0662 (Bacillus sp., ERNNT), EntF-metabolite (Enterococcus faecium, SNLVECVFSLFKKCN) and EDF-derived (Escherichia coli, NWN) peptides initiate tumour cell invasion and migration through epithelial to mesenchymal (EMT)-like transition as well as promote angiogenesis. Transcriptome profiling after peptide treatment of the HCT-8/E11 cells confirmed their tumour-promoting properties by up- or downregulation of different microRNAs (e.g. miR-664a and miR-222) and other genes (e.g. CXorf61 and Histone cluster 1 H4).[3] Our results indicate that the human microbiome, through their quorum sensing peptides, is one of the factors responsible for tumorigenesis. These findings may offer new prospects in cancer prevention and therapy.