Heterogeneity in tumor cell energetic metabolome at different cell cycle phases of human colon cancer cell lines

In this present study, the efficacy of metabolomics as a tool for tumor cell energetics for in vitro cell cultures was demonstrated with full competence for the first time by elucidating the anabolic and energy-yielding segments of glycolysis and glutaminolysis, which constitute a part of energy metabolism in tumor cells. By synchronizing colon cancer cells SW480 and SW620 in culture, the metabolome specific to cell cycle phases was analyzed using nuclear magnetic resonance spectroscopy. At the G₁/S transition of the cell cycle (i.e. transition from cell growth to duplication of genetic material), the majority of the energy production was realized by glycolysis through a high channeling of glucose carbons towards lactate. During the late S phase, the majority of energy was produced by glutaminolysis through a high channeling of glutamine carbons towards lactate, while the glucose carbons were channeled towards bio-synthetic pathways. These results indicate that the metabolism of proliferating cells is heterogeneous throughout the cell cycle and can be better interpreted on the basis of different cell cycle phases. These findings could be exploited for the development of a tool for tumor diagnosis as well as for targeting tumors.