Trimethylamine N-Oxide Promotes Cell Proliferation and Angiogenesis in Colorectal Cancer

Background. Of all intestinal microbiome-derived metabolites, trimethylamine N-oxide (TMAO) has received increasing attention because of its potent role in colorectal cancer development. Accumulating evidence suggests that TMAO generated by the gut microbiota is a new and important player in the etiological process of colorectal cancer. Nevertheless, the carcinogenic mechanism of TMAO in colorectal cancer remains unclear. In this study, TMAO induced colorectal cancer cell proliferation and produced higher vascular endothelial growth factor A (VEGFA) levels in vitro. In vivo, after long-term choline feeding in tumor-bearing mice, circulating TMAO levels, tumor volume, new blood vessel formation, and VEGFA and CD31 amounts were increased significantly. This study revealed that TMAO exerts oncogenic effects by promoting cell proliferation and angiogenesis in colorectal cancer.