Metabolism is defined as the chemical processes that enable a living organism to maintain life.
An indispensable metabolic process is energy production that must occur to provide "fuel" for cells to carry out necessary activities and maintain life.
Glucose is converted to ATP (adenosine triphosphate), in which cellular fuel is stored to enable and sustain cellular activities. A single glucose molecule can generate 32 ATP molecules via a three-stage process: (1) glycolysis, (2) citric acid cycle, and (3) oxidative phosphorylation.
In normal healthy cells, glycolysis yields 2 molecules of ATP, citric acid cycle adds another 2 ATP molecules, and oxidative phosphorylation adds the remaining 28 molecules of ATP. Clearly, glycolysis alone is not an efficient means for ATP production. Normal cells rely on all three stages for efficient ATP production.
Cancer cells rely on glycolysis to generate two ATP molecules. To compensate for this inefficiency of ATP production, cancer cells speed up ATP production as well as increase glucose transporter levels. The increased levels of glucose transporter proteins on the cell surface help transport more glucose molecules intracellularly.
Cancer cells’ sugar reliance during glycolysis is not the only means to glean cellular fuel. Cancer cells are also dependent on an amino acid called glutamine as nutrient for growth and survival. Starving cancer cells of glucose and glutamine has been proposed as a potent way to harness cancer cells. That said, since normal cells also rely on the same nutrients for needed cellular activities, a systemic deprivation would deleteriously affect normal cells as well. Accordingly, cancer-specific deprivation would be required.
