Lactobacillus brevis T2102 suppresses the growth of colorectal cancer cells by activating SIRT1

SIRT1 is known to have critical functions in the maintenance of homeostasis and cell survival, and it confers anti-ageing effects on cells and tissues. To identify novel foods and food ingredients with potential anti-ageing functions, a novel system for screening substances that activate the SIRT1 promoter in human colorectal cancer cells was established. We screened several lactic acid bacteria (LAB) and identified Lactobacillus brevis T2102 as a SIRT1-activating strain of LAB. T2102 inactivated β-catenin through SIRT1-mediated deacetylation and consequently suppressed the growth of the human colorectal cancer cell line DLD-1. Furthermore, T2102-induced degradation of β-catenin repressed transcription of the human telomerase reverse transcriptase (hTERT) gene, one of the target genes of β-catenin, which led to the induction of cellular senescence and concomitant growth suppression of DLD-1. These results indicate that SIRT1-activating T2102 might be a promising candidate for developing novel functional foods with anti-cancer properties.