The critical role of the microbiota in the pathogenesis of colorectal cancer (CRC) is increasingly being recognized. In this context, we recently demonstrated the carcinogenic effect of Cytotoxic Necrotizing Factor-1 (CNF1), produced by pathogenic E. coli strains, in a mouse model of inflammatory bowel disease (1). Previous studies had also demonstrated that CNF1, by permanently activating Rho-GTPases in epithelial cells, promotes actin polymerization, increases cell motility, and induces epithelial-to-mesenchymal transition (EMT) (2). Based on these findings, we hypothesized that CNF1 may actively contribute to CRC progression and metastatic dissemination. We observed that CNF1 induces cellular senescence in CRC cells (HT29) as testified by cell cycle arrest and beta-galactosidase staining and stimulates the production of the associated senescence-associated secretory phenotype, which is enriched in pro-inflammatory cytokines and growth factors. Indeed, supernatants from senescent cells could stimulate the proliferation of naïve tumor cells. In vivo, intrarectal CNF1 markedly accelerated tumor development in mice treated with AOM+DSS. Exposure of metastatic CRC cells (SW620) to CNF1 enhanced their migratory and invasive capacities and upregulated the expression of matrix metalloproteinases-2 and -9, which are critical for extracellular matrix remodelling. Consistently, DNA methylation analysis in CNF1-treated SW620 cells revealed a general decrease in methylation at the promoter regions of the TWIST and CD44 genes, both involved in EMT regulation. Finally, preliminary in vivo experiments showed earlier metastatic dissemination of CNF1-treated SW620-luciferase positive cells compared to controls. Taken together, these results suggest that exposure of CRC cells to CNF1 accelerates tumor progression and enhances metastatic potential. BIBLIOGRAPHY 1. Tozzi et al., 2025 DOI: 10.1186/s13046-024-03271-w 2. Fabbri et al., 2019 DOI: 10.1111/cmi.13138
The bacterial toxin CNF1 accelerates colorectal cancer progression and metastatic spread / Laterza, Ilenia; Tozzi, Michela; Angela Pia Germinario, Elena; Travaglione, Sara; Fiore, Alessia; Gambardella, Lucrezia; Rossi, Stefania; Michelini, Zuleika; Cara, Andrea; Maroccia, Zaira; Tomasoni, Sofia; Verin, Ranieri; Leoni, Omar; De Luca, Gabriele; Spada, Massimo; Khoueiry, Rita; Herceg, Zdenko; Biffoni, Mauro; Bracci, Laura; Fabbri, Alessia. - (2025). (Intervento presentato al convegno 10° ACC annual meeting-New technologies and strategies to fight cancer tenutosi a Verona).
The bacterial toxin CNF1 accelerates colorectal cancer progression and metastatic spread
Ilenia Laterza;Michela Tozzi;Sara Travaglione;Alessia Fiore;Andrea Cara;Alessia Fabbri
2025
Abstract
The critical role of the microbiota in the pathogenesis of colorectal cancer (CRC) is increasingly being recognized. In this context, we recently demonstrated the carcinogenic effect of Cytotoxic Necrotizing Factor-1 (CNF1), produced by pathogenic E. coli strains, in a mouse model of inflammatory bowel disease (1). Previous studies had also demonstrated that CNF1, by permanently activating Rho-GTPases in epithelial cells, promotes actin polymerization, increases cell motility, and induces epithelial-to-mesenchymal transition (EMT) (2). Based on these findings, we hypothesized that CNF1 may actively contribute to CRC progression and metastatic dissemination. We observed that CNF1 induces cellular senescence in CRC cells (HT29) as testified by cell cycle arrest and beta-galactosidase staining and stimulates the production of the associated senescence-associated secretory phenotype, which is enriched in pro-inflammatory cytokines and growth factors. Indeed, supernatants from senescent cells could stimulate the proliferation of naïve tumor cells. In vivo, intrarectal CNF1 markedly accelerated tumor development in mice treated with AOM+DSS. Exposure of metastatic CRC cells (SW620) to CNF1 enhanced their migratory and invasive capacities and upregulated the expression of matrix metalloproteinases-2 and -9, which are critical for extracellular matrix remodelling. Consistently, DNA methylation analysis in CNF1-treated SW620 cells revealed a general decrease in methylation at the promoter regions of the TWIST and CD44 genes, both involved in EMT regulation. Finally, preliminary in vivo experiments showed earlier metastatic dissemination of CNF1-treated SW620-luciferase positive cells compared to controls. Taken together, these results suggest that exposure of CRC cells to CNF1 accelerates tumor progression and enhances metastatic potential. BIBLIOGRAPHY 1. Tozzi et al., 2025 DOI: 10.1186/s13046-024-03271-w 2. Fabbri et al., 2019 DOI: 10.1111/cmi.13138I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
