Nearly 90 years ago, German physician Otto Warburg noticed cancer cells behaved differently. Instead of using oxygen to turn food into energy, as healthy cells do, cancer cells feed off glucose.
A molecule, lactate, is the end-product of the Warburg effect, and scientists have assumed it is nothing more than a waste product. But a research team from the University of Chicago have discovered that lactate has an active part to play in the creation of other cells that also start feeding off glucose, and so become cancerous.
It is through the production of lactate that cancers spread, the researchers found, as they act as a regulator of other cells, changing the way they feed.
The process starts with immune system cells called macrophages. These cells produce lactate when there is a bacterial infection or a lack of oxygen supply in tumors. Although the lactate helps control damage during infection, it promotes the growth and spread of cancer cells.
A similar process happens in other diseases, too, such as sepsis, auto-immune disease, atherosclerosis, or hardening of the arteries, diabetes and ageing, and so the discovery of lactate's role could