Colibactin-Producing <i>Escherichia coli</i> Induce the Formation of Invasive Carcinomas in a Chronic Inflammation-Associated Mouse Model.

Authors:
Laurène Salesse, Cécily Lucas, My Hanh Thi Hoang, Pierre Sauvanet, Alexandra Rezard, Philip Rosenstiel, Christelle Damon-Soubeyrand, Nicolas Barnich, Catherine Godfraind, Guillaume Dalmasso, Hang Thi Thu Nguyen
Year of publication:
2021
Volume:
13
Issue:
9
Issn:
2072-6694
Journal title abbreviated:
Cancers (Basel)
Journal title long:
Cancers
Impact factor:
6.575
Abstract:
<h4>Background</h4><i>Escherichia coli</i> producing the genotoxin colibactin (CoPEC or colibactin-producing <i>E. coli</i>) abnormally colonize the colonic mucosa of colorectal cancer (CRC) patients. We previously showed that deficiency of autophagy in intestinal epithelial cells (IECs) enhances CoPEC-induced colorectal carcinogenesis in <i>Apc<sup>Min/+</sup></i> mice. Here, we tested if CoPEC trigger tumorigenesis in a mouse model lacking genetic susceptibility or the use of carcinogen.<h4>Methods</h4>Mice with autophagy deficiency in IECs (<i>Atg16l1</i><sup>∆<i>IEC</i></sup>) or wild-type mice (<i>Atg16l1<sup>flox/flox</sup></i>) were infected with the CoPEC 11G5 strain or the mutant 11G5∆clbQ incapable of producing colibactin and subjected to 12 cycles of DSS treatment to induce chronic colitis. Mouse colons were used for histological assessment, immunohistochemical and immunoblot analyses for DNA damage marker. <i>Results</i>: 11G5 or 11G5∆clbQ infection increased clinical and histological inflammation scores, and these were further enhanced by IEC-specific autophagy deficiency. 11G5 infection, but not 11G5∆clbQ infection, triggered the formation of invasive carcinomas, and this was further increased by autophagy deficiency. The increase in invasive carcinomas was correlated with enhanced DNA damage and independent of inflammation. <i>Conclusions</i>: CoPEC induce colorectal carcinogenesis in a CRC mouse model lacking genetic susceptibility and carcinogen. This work highlights the role of (i) CoPEC as a driver of CRC development, and (ii) autophagy in inhibiting the carcinogenic properties of CoPEC.