Glyoxylate supplementation ameliorates colitis associated colon cancer progression.

Abstract

Colon cancer is on the rise in younger adults. Despite multimodal treatment strategies, clinical outcomes in advanced stage colon cancer patients remain poor. Neoadjuvant/adjuvant chemotherapy efficacy is limited due to chemoresistance, toxicity, and negative side effects. Overwhelming evidence supporting the small-molecule metabolites derived from breakdown of food or microbial sources confer an extensive array of host benefits, including chemo-preventive role in colon cancer. Our previous study indicated that the introduction of glyoxylate (Glx), an intermediate product of microbial or plant metabolism, exerts a cytotoxic effect in colon cancer cells. This study was designed to evaluate the effects of Glx on colon cancer with molecular insights. For this, we established an AOM/DSS-induced colitis associated colon cancer model in mice. Supplementation of Glx in vivo reduced colitis associated tumor growth and altered the metabolic characteristics of tumor tissue in mice without initiating any severe liver or renal toxicity. More specifically, intake of glyoxylate accumulated glycine in the colon tissue by elevation of alanine-glyoxylate transferase (AGXT) activity. Glycine accumulation increased intracellular Ca²⁺ concentration via glycine receptor activation and dysregulation of Ca²⁺ homeostasis lead to induction of apoptosis that resulted in arresting tumor growth. Interestingly, elevation of AGXT activity or Glx related specific metabolic pathway provides better survival in colon cancer patients. Collectively, our exclusive findings support the exploration of Glx either as a preventive molecule or its inclusion in the treatment regimens for colon cancer.