The role of Escherichia coli in the pathogenesis of colorectal cancer

Background and Aim : Colorectal cancer (CRC) is the third most common cancer in the world. Specific strains of mucosa-associated Escherichia coli (E. coli) can influence the initiation and development of CRC through toxin-mediated DNA damage and by promoting inflammatory pathways. The aim of this study was to review the role of mucosa-associated E.coli in the pathogenicity of CRCMethods : We’ve searched PubMed, Google scholar, SID and Magiran databases from the year ۱۹۹۰ to ۲۰۲۱ for keywords such as mucosa-associated E. coli, colorectal cancer, colibactin, inflammation and risk factors among published articles.Results : The results of various studies indicated that mucosa-associated E.coli is more frequently isolated from patients with CRC than in healthy subjects. Interestingly, majority E.coli strains from CRC patients carried pks genomic island. This genomic island encodes colibactin toxin that induces DNA damage and chromosomal instability which may play a potential role in CRC carcinogenesis. Moreover, pks+ E.coli induce the cellular senescence and production of growth factors leading to increased tumor growth. Furthermore, E. coli strains from B۲ phylogroup can survive and replicate within macrophages and induce chronic inflammation. It is noteworthy that chronic inflammation is an important risk factor for CRC.Conclusion : It seems that some strains of mucosa-associated E.coli especially colibactin- producing E.coli may play a key role in CRC carcinogenesis but more research is needed to confirm the cancer-promoting potential of these strains.

کلیدواژه ها:

E. coli ، Colorectal cancer ، Colibactin ، Inflammation