The mystery enzyme: how cancer cells feed off sugar!
Cancer cells feed off sugar in order to grow, as Otto Warburg observed in the 1920s—and now scientists have figured out how they do it. Solving this '100-year-old mystery', as they call it, finally opens the door to better and safer treatments.
Back in the 1920s, Dr Warburg, a physiologist, discovered that cancer cells need glucose—the sugar in our blood—to thrive and grow. It's their primary energy source, and yet they choose an extremely inefficient way of getting that energy.
Healthy cells use the mitochondria, the energy-producing structures within cells, to produce ATP (adenosine triphosphate), which drives most of our functions. But cancer cells are different; they change their metabolism and cease to rely on oxygen, in order to ferment sugar in what became known as the Warburg effect.
"This has been a mystery for quite some time. Why would cancer cells, which need large amounts of energy to sustain their growth, prefer to use a pathway that produces less ATP than another available pathway?" asked Prof Bert O'Malley from Baylor College of Medicine.
Years ago, O'Malley and his team discovered that cancer cells over-produce the protein SRC-3, and this allows them to turn on genes that cause abnormal growth and metastasis (growth), characteristics of cancer.
So what makes a cancer cell produce more SRC-3? The unsuspected culprit is an enzyme known as PFKFB4, and this turns SRC-3s into potent drivers of most cancers, and especially breast cancer.
This opens the door to new cancer therapies. Just remove either the PFKFB4s or the SRC-3s from cancer cells, and you stop it in its tracks. Cancer stops growing and it can't come back.