British scientists have taken a step forward in their effort to find out why breast cancer spreads to other parts of the body.
Cancer cells extend tiny antennae to help them move around
They have found that certain types of cancerous cells are attracted to other areas by a naturally occurring protein.
They have shown that blocking this protein, which is called uPA, can stop the cancer from spreading.
Writing in the Journal of Cell Biology, they said the discovery could lead to new treatments to fight the disease.
Professor Clare Isacke and colleagues at the Breakthrough Breast Cancer Research Centre in London studied breast cancer cells, which express a protein called Endo180, in the laboratory.
They found that this protein plays a key role in the formation of filopodia or the tiny antennae which extend from the cell and enable it to move around.
They also found that cells with this protein are attracted to uPA.
They discovered that cancer cells no longer moved to other parts of the body if either of these two proteins are missing.
They also discovered that blocking the uPA protein stopped these cancer cells from spreading.
Scientists do not know what proportion of breast cancer cells carry the Endo180 protein.
However, Professor Isacke said cells with this protein are more invasive and are more likely to spread.
She said the research team were now starting work to identify how many cancer cells carry the protein.
They are also carrying out further tests to see what impact blocking the uPA protein would have on the body.
More than 40,000 women and 300 men are diagnosed with breast cancer in the UK each year.
The disease can be cured if caught early. Problems arise when the cancer spreads to other parts of the body.
The scientists believe that understanding how this happens could lead to new treatments to fight the disease.
"Preventing the spread of breast cancer is key to removing its fatality," said Professor Isacke.
"Now we have a crucial understanding of how cells move in particular directions we have the potential to identify new methods to diagnose, prevent and treat the spread of breast cancers."