Cancer metastasis in the lung. Cancer cells can be seen in white, with proliferative cells in pink and type two lung alveolar cells in green. Credit: Tumour-Host Interaction Laboratory.
A scar still present on your leg, decades after you fell from your bike as a child, is a visible example of the body’s fascinating ability to regenerate.
After that accident, chemical messages caused new cells to rush to the site and repair the damage, provoking the development of replacement cells and new blood vessels.
All these phenomena – chemical signalling, migrating and dividing cells, and new blood vessel growth – are also hallmarks of cancer. So, one way to view cancer is as the result of a healing process gone wrong. And this way of thinking is helping researchers understand how cancer cells hijack the powerfully regenerative biology of wound healing to spread, and to create a new environment in which they can grow.
Of the around 30 trillion cells in the human body, the vast majority stay put, held in place within our tissues and organs by strict molecular instructions. Ilaria Malanchi and her team at the Crick’s Tumour-Host Interaction Lab are trying to decipher those instructions, to understand how cancer cells interact with healthy cells in the body and corrupt them to enable their spread.
It’s this ability to spread that makes some cancers so hard to treat.
“Cancer affects more than just the part of the body where it first developed, it’s a systemic disease that sparks changes to many aspects of our biology, even at the very earliest stages,” Ilaria says.
Her team recently examined what happens as breast cancer cells spread and reach the lungs in mice. They found that, as cancer cells reach the lungs, they prompt cells called alveolar cells - normally the site of oxygen exchange – to de-specialise and enter a state generally associated with repair after an injury. This releases chemical messages that, in turn, allow the breast cancer cells to successfully grow and divide in the lungs, effectively ‘hijacking’ the body’s wound healing processes.
Examining how cells in different organs respond to different types of cancer will help researchers understand why some cancer types are more likely to spread than others, and also why some cancer types commonly spread to specific organs, like breast cancer to the lungs or lung cancer to the liver. If they can pin down the precise biological signals associated with these changes, it may open up opportunities to hold cancer in its place, improving the chance of successful treatment.
“If we think of cancer as hijacked wound healing, we can bring a sense of order to the apparent unpredictability of cancer spread, and maybe even prevent it,” says Ilaria.
Science from inside the Crick.
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