Cellular metabolomics study in colorectal cancer cells and media following treatment with 5-fluorouracil by gas chromatography-tandem mass spectrometry

Abstract

Background: Metabolic reprogramming is a distinctive characteristic of colorectal cancer (CRC) which provides energy and nutrients for rapid proliferation. Although numerous studies have explored the rewired metabolism of CRC, the metabolic alterations occurring in CRC when the cell cycle is arrested by treatment with 5-fluorouracil (5-FU), an anticancer drug that arrests the S phase, remain unclear.

Methods: A systematic profiling analysis was conducted as ethoxycarbonyl/methoxime/tert-butyldimethylsilyl derivatives using gas chromatography-tandem mass spectrometry in HT29 cells and media following 5-FU treatment in a concentration- and time-dependent manner.

Results: In HT29 cells of 24 h after 5-FU treatment (3-100 μM) and 48 h after 5-FU treatment (1-10 μM), six amino acids, including valine, leucine, isoleucine, serine, glycine, and alanine and two organic acids, including pyruvic acid and lactic acid, were significantly increased compared to the DMSO-treated group. However, 48 h after 5-FU treatment (30-100 μM) in HT29 cells, the levels of these metabolites decreased along with an approximately 50% reduction in viability, an increase in the level of reactive oxygen species, induction of cycle arrest in the G1 phase, and the induction of apoptosis. On the other hand, the levels of fatty acids showed a continuous increase in HT29 cells 48 h after 5-FU treatment (1-100 μM). In the media, the decreased availabilities in the cellular uptake of nutrient metabolites, including valine, leucine, isoleucine, serine, and glutamine, were observed at 48 h after 5-FU treatment in a dose-dependent manner.

Conclusion: It is assumed that there is a possible shift in energy dependence from the tricarboxylic acid cycle to fatty acid metabolism. Thus, metabolic profiling analysis revealed altered energy metabolism in CRC cells following 5-FU treatment.

Keywords: 5-Fluorouracil; Colorectal cancer; HT29 cells; Mass spectrometry; Metabolite profiling analysis; Metabolomics.