Colibactin-producing Escherichia coli enhance resistance to chemotherapeutic drugs by promoting epithelial to mesenchymal transition and cancer stem cell emergence

ABSTRACT

Human colorectal cancers (CRCs) are readily colonized by colibactin-producing E. coli (CoPEC). CoPEC induces DNA double-strand breaks, DNA mutations, genomic instability, and cellular senescence. Infected cells produce a senescence-associated secretory phenotype (SASP), which is involved in the increase in tumorigenesis observed in CRC mouse models infected with CoPEC. This study investigated whether CoPEC, and the SASP derived from CoPEC-infected cells, impacted chemotherapeutic resistance. Human intestinal epithelial cells were infected with the CoPEC clinical 11G5 strain or with its isogenic mutant, which is unable to produce colibactin. Chemotherapeutic resistance was assessed in vitro and in a xenograft mouse model. Expressions of cancer stem cell (CSC) markers in infected cells were investigated. Data were validated using a CRC mouse model and human clinical samples. Both 11G5-infected cells, and uninfected cells incubated with the SASP produced by 11G5-infected cells exhibited an increased resistance to chemotherapeutic drugs in vitro and in vivo. This finding correlated with the induction of the epithelial to mesenchymal transition (EMT), which led to the emergence of cells exhibiting CSC features. They grew on ultra-low attachment plates, formed colonies in soft agar, and overexpressed several CSC markers (e.g. CD133, OCT-3/4, and NANOG). In agreement with these results, murine and human CRC biopsies colonized with CoPEC exhibited higher expression levels of OCT-3/4 and NANOG than biopsies devoid of CoPEC. Conclusion: CoPEC might aggravate CRCs by inducing the emergence of cancer stem cells that are highly resistant to chemotherapy.

KEYWORDS:

• Colorectal cancer
• colibactin
• pks
• chemotherapy resistance
• cancer stem cell
• microbiota
• Escherichia coli
• CoPEC

Acknowledgments

The authors thank Anne-Sophie Marinelli for her technical assistance, Dr Céline Bourgne for her help with the flow cytometry (Plateforme de cytométrie en flux, CHU Clermont-Ferrand), and the platform CLIC (Clermont-Ferrand Imagerie Confocale, Université Clermont Auvergne) for assistance with the microscopy. This study was supported by the Ministère de la Recherche et de la Technologie, Inserm (UMR 1071), INRAe (USC 1382), the French government’s IDEX-ISITE initiative 16-IDEX-0001 (CAP 20-25), and the ITMO Cancer AVIESAN (Alliance Nationale pour les Sciences de la Vie et de la Santé, National Alliance for Life Sciences & Health) within the framework of the Cancer Plan (HTE201601).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author, GD, upon reasonable request.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/19490976.2024.2310215

Additional information

Funding

The work was supported by the Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement [USC 1382]; Institut National de la Santé et de la Recherche Médicale [U1071]; Ministère de l’Education Nationale, de l’Enseignement Supérieur et de la Recherche [IDEX-ISITE initiative 16-IDEX-0001]; AVIASAN [HTE201601].