Many people with cancer die not from their original tumour, but from secondary tumours that grow elsewhere around the body. Now we’re a step closer to understanding how cancers are able to spread.
of the Medical Research Council Cancer Unit at the University of Cambridge and his colleagues have been studying kidney cancer cells. They found that to spread, these cells tap into the same genetic “travel” machinery normally used by healthy white blood cells to roam around the body.
They discovered this by comparing how active different genes were in the cells of four types of human kidney cancer – two of which were capable of spreading. They found that those that could spread had increased activity in two regions of the genome that act as accelerator pedals, amplifying the activity of nearby genes.
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These “enhancers” lead to increased activity of a gene called CXCR4, which is known to help white blood cells move around the body and into other organs to fight infections or disease. The gene was 10 to 20 times more active in the kidney cancer cells that could spread than in those that couldn’t.
Turn it off
When the team studied databases of human and mouse gene activity, they found that the same two enhancers are normally only active in healthy white blood cells. The team found that silencing these enhancers in kidney cancer cells stopped them from being able to spread when they were injected into mice. When they reactivated the silencers, they began to move around the body again.
“They are changing identity,” says Vanharanta. “It’s not that they’ve become something else completely, but that they’ve stolen a collection of different tricks from other types of cells.”
Vanharanta believes that other cancers may also spread by stealing other cells’ tricks, and has some evidence this happens with breast cancer too. Ultimately, he says, it might be possible to stop cancers spreading by targeting these enhancers, but more work is needed first, he says.
“The mechanisms used by cancer cells to spread through the body are still poorly understood,” says Marco Gerlinger of the UK Institute of Cancer Research. “These new insights could lead to new ways to predict whether a cancer is dangerous and likely to spread.”
Cancer Discovery
Read more: Breast cancer impersonates neurons to invade the brain
