Dissecting cellular metabolism during the cell cycle

N. SCAGLIA; C. PHOTOPOULOS; M. LODA

Congreso; Gordon Research Conferences. Molecular & Cellular Biology of Lipids; 2011

The cell cycle is altered in several pathological states, including cancer. Although the signals that initiate and drive cell cycle progression have been intensively studied, much less is known about the cellular metabolic needs during different phases of the cell cycle and how the cells fulfill those requirements. The objective of this study is to dissect the metabolic changes occurring through the mammalian cell cycle, focusing on 3 pathways that are important for cellular proliferation and survival in cancer cells: lipogenesis, glycolysis and glutaminolysis. To do so, HeLa cells were synchronized by double thymidine block. The progression through the cell cycle was assessed by FACS analysis with bromodeoxyuridine and propidium iodine staining. Preliminary results showed that the de novo synthesis of fatty acids increases as the cells reach G1 phase of the cell cycle. Both glucose and glutamine provided carbon skeletons for lipid synthesis. The production of lactate did not changed in a periodic manner, suggesting that the overall rate of aerobic glycolysis and glutaminolysis are not regulated in a cell cycle dependent manner. To gain further insights into the metabolic profile of the cells at different phases of the cell cycle, a GC/MS and LC/MS/MS analysis was performed. As expected, the metabolites that changed most drastically throughout the cell cycle were those related to DNA metabolism. A preliminary analysis showed that the levels of several metabolites of lipid, glucose and aminoacid metabolism were also regulated in a phase-specific manner and suggested that the metabolic fate of different nutrients changes with cell cycle progression. These results contribute to the understanding of the regulation of cellular metabolism during proliferation and lay the groundwork for testing whether a combined approach targeting the cell cycle and specific metabolic pathways is beneficial for cancer therapy.