Kynurenic acid enhances expression of p21 Waf1/Cip1 in colon cancer HT-29 cells

BackgroundKynurenic acid (KYNA), a tryptophan metabolite, was found in the mucus of rat small intestine. However, its role in the gastrointestinal tract is still not fully elucidated.MethodsTo verify whether KYNA affects cell cycle regulators, the protein expression of cyclin-dependent kinase inhibitor p21 Waf1/Cip1 was investigated in colon adenocarcinoma HT-29 cells exposed to KYNA. MTT, BrdU assay and siRNA technology were used to evaluate the effect of KYNA on cancer cell proliferation.ResultsKYNA significantly enhanced the expression of p21 Waf1/Cip1. Importantly, the overexpression of this protein was involved in inhibition of proliferation and DNA synthesis in HT-29 cells.ConclusionsKYNA may be considered as a potential chemoprevention agent against colon cancer.