A new study by scientists at the Massachusetts Institute of Technology (MIT) has found how cancer cells use an unusual process of multiplication. The study, which answers a long-standing mystery about the proliferation of unhealthy cells in the human body, will be published in Molecular cell magazine.
The study was conducted by MIT biologist Matthew Vander Heiden, lead author of the new study, and lead authors, former MIT graduate student and postdoctoral student Alba Luengo (PhD ’18) and graduate student Zhaoqi Li. His research showed that the metabolic process, known as fermentation, helps cancer cells regenerate large amounts of a molecule called NAD +, which they need to synthesize DNA and other important molecules. Speaking to MIT News, Heiden said that according to his study under certain circumstances, cells need to do more of the electron transfer reactions, which require NAD + to make molecules like DNA.
Fermentation is a way in which cells can convert the energy found in sugar into adenosine triphosphate (ATP). ATP is a chemical used by cells to store energy for their needs. Humans use a process called aerobic respiration where cells break down sugar to access more ATP. However, cells switch to a less efficient method called fermentation when there is a lack of oxygen in the cells.
German chemist Otto Warburg discovered that it is usually cancer cells that metabolize sugar through the fermentation process. Since then, scientists have proposed several theories to justify why cancer cells switch to a more lethargic way of breaking down cells but with little success.
To understand this reason, MIT scientists avoided the ability of cancer cells to perform the fermentation process. With this, they observed that the growth of cancer cells was hindered. Researchers introduced another method of cell growth by stimulating cells to produce NAD +, a molecule that helps cells get the extra electrons left out when cells make molecules such as DNA and proteins. .
With this experiment, the researchers found that the cells began to proliferate again, despite their inability to perform fermentation. The results produced by this study led the researchers to conclude that when cells grow rapidly, they need NAD + more than they need ATP. And because in aerobic respiration, cells produce a lot of ATP and some NAD +, they go on to ferment. The scientists found that if cells accumulate more ATP than they can consume, their silk respiration and NAD + production is also reduced.