Pathway for cancer spread is discovered

In collaboration with the Press Association

Scientists have discovered one of the mechanisms that enables cancer to metastasise, or spread, throughout the body.

Once a tumour is established, cells can break off, cross blood vessel walls and travel through the blood stream to other parts of the body.

If they take root here, they form secondary tumours. This is called metastasis and is often what makes cancer difficult to treat.

One of the body's natural defences against metastasis involves a protein known as MUC1 .

"MUC1 on the cell surface prevents the cancer cells from attaching to the blood vessel wall," said lead researcher Dr Lu-Gang Yu, of the University of Liverpool. But this protection is disrupted by a second protein, the research team found.

"We have discovered that a small protein called galectin-3, attacks MUC1 and breaks up its protective shield, forcing large areas of the cancer cell to become exposed," said Dr Yu.

Proteins on these exposed areas of the cell surface allow the cancer cell to attach to the blood vessel wall. The cells then penetrate the wall and enter the blood stream.

Previous research has found that patients whose cancer has spread have high-levels of galectin-3 in their blood, but this is the first study to show that the protein is directly involved in metastasis.

"Our study indicates that galectin-3 may play a critical role and may have significant implications for future developments of drugs for the treatment of the disease," Dr Yu added.

The study is published in the Journal of Biological Chemistry.