Metastasising tumours, a process by which cancer cells detach from an initial tumour and form new tumours elsewhere in the body, leaves a metabolic byproduct known as methylmalonic acid (MMA) that appears to accumulate with age and is crucial to the development and spread of cancer.

In finding ways to block metastasising tumours, scientists at Weill Medical College of Cornell University (Weill Cornell Medicine) in NYC, US, noticed that cancer cells in select blood samples developed changes attributed to MMA, such as increased “migratory and invasive capacity” as well as resistance to two drugs often used to treat cancers.

The scientists later chose to block the expression of a gene (SOX4) in mice to see if it was altering MMA levels and the qualities of cancer cells. Indeed, blocking SOX4 seemed to reduce MMA and also stopped the process by which the cancer cells were able to resist two cancer treatments.

“This discovery is the beginning of many investigations in many different directions,” said John Blenis, a professor of pharmacology at Weill Cornell Medicine. “Our hope overall is that we’ll be able eventually to develop therapies to reduce MMA levels and thereby reduce cancer mortality.”

The scientists hypothesise that drugs that reduce MMA levels might potentially reduce the aggressive spread of cancers in patients, while a low-protein diet might decrease MMA accumulation and help cancer patients respond better to treatment.