Autoinducer-2 of gut microbiota, a potential novel marker for human colorectal cancer, is associated with the activation of TNFSF9 signaling in macrophages

Abstract

Objectives: The interaction between the quorum sensing (QS) molecules of gut microbiota and the immunity of colorectal cancer (CRC) has not been investigated before. Methods: We measured the concentration of autoinducer-2 (AI-2) in samples of stool, colorectal tissue, saliva and serum of CRC patients, and compared this to AI-2 levels in colorectal adenoma (AD) and normal colon mucosa (NC). To explore the activated signaling pathways involved, we utilized AI-2 extracted from Fusobacterium nucleatum to stimulate macrophages and validated these in vitro findings in human CRC tissues. Results: The AI-2 concentration in both colorectal tissue and stool of CRC patients was significantly higher when compared to that in AD and NC (all P values