JAK, a protein, makes a cancer cell contract, which allows them to squeeze through small spaces and spread beyond the tumor and into other parts of the body, researchers from The Institute of Cancer Research, London, INSERM, France, and the University of Nice, France, wrote in the journal Cancer Cell.

When JAK is “switched on”, the cancer cell undergoes muscle-like contractions that allows it to move and eventually be squeezed out.
The authors suggest that medications that could target JAK might be able to stop metastasis – when cancer spreads beyond the tumor. 90% of cancer-related deaths occur when the cancer spreads beyond the tumor.

Tumors are made up of tumor-associated healthy cells, cancer cells, and the cell matrix (scaffolding that sticks everything together). Cancer cells metastasize when they move from the tumor, through the matrix, to new areas (outside the tumor).

The authors explain that in some kinds of cancer, the cancer cells elbow their way through the matrix with a force similar to muscle contractions. In other cancers, the healthy cells in the tumor create tunnels through which the cancer cells move.

The researchers demonstrated that the same processes are used to create a force in cancer cells and the tumor associated healthy cells.

Lead author Professor Chris Marshall, said:

“There’s an urgent need to understand how tumors can spread from their site of origin, for example the skin, to other tissues, such as the lungs, liver and bone where the disease becomes more difficult to treat successfully.

We’ve shown that the same protein called JAK triggers tumor spread via two different routes – it generates the force needed for cancer cells to move around the body and also for triggers healthy cells in tumours to create furrows in tissues down which cancer cells move.

Encouragingly drugs that block JAK are already in development to stop the growth of tumours. Our new study suggests that such drugs may also stop the spread of cancer.”

Dr Lesley Walker, Cancer Research UK’s director of cancer information, said:

“A huge challenge in successfully treating cancer is stopping it from spreading around the body, and keeping cancer that has already spread at bay. Most deaths from cancer are caused when cancer cells travel to different parts of the body and grow as secondary tumors.

Discovering how cancer cells can funnel grooves though tissues, to squeeze away from primary tumors and spread to new sites, gives scientists fresh understanding of ways to stop cancer spread – literally in its tracks.”

Written by Christian Nordqvist