Investigation of extracellular metabolites in cancer and healthy colon cells in a time-dependent manner

Metabolite analysis is critical in the cancer field because of provides information about the metabolic status of cells. The profiling of extracellular metabolites presents technical advantages over intracellular metabolites, such as easier access to extracellular metabolites without a quenching method and the growth medium containing high biomass. This study aimed to investigate the extracellular level of metabolites in colon cancer cells in a time-dependent manner. One million cells were seeded in 4 Petri dishes and glucose, pyruvate, TCA cycle metabolites, and D2-HG in the conditioned medium were determined by DNS and HPLC method and pyruvate assay for 24-96th hours. The results showed that glucose is consumed, and pyruvate and TCA cycle intermediates are released in decreasing amounts in all cell lines. It was also observed that glucose was more consumed, and TCA cycle metabolites were less released in metastatic colon cancer cells (SW620) than in primary colon adenocarcinoma cells (Caco-2). Most importantly, D2-HG oncometabolite was released more into the growth medium of colon cancer cells than normal colon cells for four days. In conclusion, the D2-HG is highly produced and released to the growth medium of colon cancer cell lines in a cancer-type-specific manner.