A new approach to tackling breast cancer has been uncovered by British scientists who identified a previously unknown driver of the disease.
Working with laboratory mice, the team found that a protein called lysyl oxidase (LOX) plays an important role in helping breast cancer grow and spread.
The scientists have also designed a prototype drug that blocks LOX and in mice is able to slow the disease down.
They now hope to develop a similar medicine suitable for human patients and test it in clinical trials.
Professor Caroline Springer, from the Institute of Cancer Research, London, who co-led the research, said: "We knew that LOX had a role in cancer’s spread round the body, but to discover how it also appears to drive the growth of breast cancer cells is a real game changer.
"It means that drugs that disrupt LOX’s ability to promote growth signals might be able to slow or block cancer progression in patients - as we saw in mice."
Previously, LOX was known to help control formation of the extracellular matrix - the structure of proteins and connective material that holds tissues together and assists cancer metastasis, or spread.
The new study, published in the journal Nature Communications, showed that it also promoted cancer growth by acting on a molecular receptor called EGFR.
Blocking LOX using the inhibitor drug code-named CCT365623 slowed tumour growth and reduced cancer spread with no side effects.
Dr Justine Alford, from Cancer Research UK, whose scientists at the University of Manchester contributed to the discovery, said: "This research in mice is exciting because it not only reveals new details of how breast cancer grows and spreads, but it could lead to a completely new way to stop these processes in patients if proven in people.
"This could help improve outcomes for patients, since cancer that has spread is harder to treat.
"LOX is also thought to play a role in a number of other cancers, so this research could also have applications beyond breast cancer."