Cancer cells adjust energy balance to keep growing when nutrients run low
Cancer cells manage to proliferate even in nutrient-poor environments. A new study in lab-grown cells reveals one key reason why.
Researchers studied how shortages of amino acids or fats affect the internal energy balance of cancer cells. They focused on the ratio between two molecules that act as a cellular energy gauge: NAD+ and NADH. The study, published in eLife, shows that some cancer cells respond to a shortage of serine (an amino acid needed to build proteins and other molecules) by ramping up energy production in their mitochondria, the small structures inside cells that generate power. This raises NAD+ levels, allowing the cell to synthesize serine on its own.
Not all cancer cells respond the same way
The response varied between cell types. Cells that could ramp up energy production in their mitochondria produced more serine when serine was scarce and continued to grow better than cells without that response. This difference was independent of how much of the enzyme normally used to make serine the cells expressed. A shortage of fats also raised the NAD+/NADH ratio in some cells via the same route, including in cells that did not respond to serine deprivation.
Multiple nutrients shape cancer cell growth together
The researchers conclude that the full nutrient composition of the tumor’s immediate environment, not just any single nutrient, shapes how a cancer cell grows. They propose that their findings offer a framework for understanding why cancer cell behavior is so difficult to predict. Whether this mechanism could serve as a treatment target was not investigated in this study.
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