INTRODUCTION

Cougnoux and colleagues1 report a new mechanism by which select bacteria can drive colon cancer. Specifically, they discovered that colobactin-producing E. coli strains can activate growth-arrested (ie, senescent) cells to produce growth factors that drive tumor growth. These findings may, in part, underlie the association of such bacteria with carcinomas and could result in novel strategies to slow tumor growth.

Approximately 20% of cancers are considered to be a consequence of infection by bacteria and/or viruses typically classified as pathogens. Moreover, many cancers occur in tissues with high exposure to microbiota, such as colorectal cancers (CRC), suggesting microbes not typically thought of as pathogens in promoting carcinogenesis. For example, mucosa-associated Escherichia coli are present more frequently in colon tissue from patients with adenocarcinomas than in control subjects. While E. coli are typically present in the intestine of healthy persons, various strains of E. coli have ‘pathogen-like features’ and associate with disease resulting in them being referred …