Healthcare (Commonwealth Union) – Oxford-led research reveals platelets act as DNA ‘cleaners’ in the bloodstream, opening doors to breakthroughs in cancer detection and prenatal testing.
Scientists at the University of Oxford have identified a surprising new role for platelets—the small blood cells best known for helping blood clot. According to a Cancer Research UK–funded study published in Science, platelets don’t just control bleeding; they also act as scavengers, sweeping up and storing stray fragments of DNA found in the blood, including fetal DNA and mutated DNA shed by cancer cells. Crucially, testing platelet DNA through a simple blood draw was able to detect even early, pre-cancerous genetic changes—suggesting a powerful new tool for early diagnosis and prevention.
It has long been established that fragments of DNA enter the bloodstream as cells die. In high amounts, this “cell-free” DNA can be harmful, triggering immune responses or other health issues. Until now, it was not very clear as to how the body handled this excess. This new discover shows that platelets absorb these DNA pieces, that carry out a key role in taking them out.
A vital discovery, saw researchers at the MRC Weatherall Institute of Molecular Medicine identify fetal DNA within platelets from pregnant women, together with mutated DNA inside platelets obtained from cancer patients and even those having pre-cancerous changes. These insights could transform genetic testing techniques, many of which currently overlook platelets by analyzing only DNA from blood plasma.
Lauren Murphy, the postdoctoral researcher who led the project, indicated that their research points to platelets being far more significant for human health than previously thought. It also highlights that current liquid biopsy techniques are missing valuable genetic clues hidden inside platelets. By showing that platelets carry fragments of cell-free DNA, they open the possibility of making cancer screening tests more sensitive, which could allow cancers to be detected at a much earlier stage than before.
The team believes that their findings could pave the way for earlier detection of cancers and other genetic conditions, ultimately improving outcomes for patients.
Professor Bethan Psaila, a haematologist at the University of Oxford and senior author of the study, pointed out that they were surprised to discover that platelets act like miniature DNA cleaners in the bloodstream. A fortunate result of this is that they carry evidence of DNA damage from tissues throughout the body—meaning platelet analysis could strengthen screening methods, including those for cancer. This was a collaborative effort with colleagues at the Universities of Edinburgh and Swansea, and they are deeply grateful to their partners, to Cancer Research UK for funding, and above all to the patients who generously provided samples for this research.
Dr David Crosby, Head of Prevention and Early Detection Research at Cancer Research UK, which supported the study, pointed out that since platelets naturally lack their own DNA, the fact that they can absorb cancer-related DNA from the bloodstream is both fascinating and potentially significant. He further indicated that this breakthrough suggests that far more of a blood sample could be harnessed to detect cancers at a much earlier stage—well before symptoms arise. It could reveal cancer markers that have until now gone unnoticed.
Researchers of the study pointed out that blood tests capable of locating tiny fragments of DNA shed from tumours are already being produced. They are known as ‘liquid biopsies’ that show great promise in the clinic, for early detection as well as the detection of cancers that recur after treatment. This new finding has the potential to dramatically take the research further into new blood tests which utilize DNA collected by the platelets.
