Platelets Found to Act as ‘DNA Sponges,’ Offering New Hope for Early Cancer and Prenatal Screening
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A groundbreaking study published in Science reveals that platelets, the tiny blood cells best known for clotting, also function as reservoirs for cell-free DNA – including genetic material shed by tumors and developing fetuses.This discovery, led by researchers at ludwig Cancer Research, could dramatically improve the sensitivity of liquid biopsies for early cancer detection and enhance the accuracy of prenatal screening.
The findings suggest platelets play a crucial, previously unknown role in both limiting systemic inflammation and storing valuable genetic data. Researchers believe harnessing this ability could revolutionize how we approach early disease detection.
Beyond Clotting: Platelets’ Expanding role in Health
Interestingly, the study also found that platelets release this stored DNA when activated, suggesting a targeted delivery system that prevents widespread inflammation while enabling localized immune responses, such as at a site of injury.
The Promise of Liquid Biopsies Enhanced by Platelet DNA
The implications for cancer detection are particularly important. Cell-free DNA (cfDNA), which includes traces of circulating tumor DNA (ctDNA), is increasingly used in “liquid biopsies” to non-invasively detect cancers and monitor treatment response. Though, ctDNA levels are frequently enough extremely low, especially in early-stage disease, limiting the effectiveness of these screenings.
Currently, cfDNA for diagnostics is isolated from blood plasma after removing blood cells, including platelets. This study demonstrates that a ample portion of cfDNA, including tumor-derived DNA, resides within platelets, meaning a vital source of information is being discarded.
“We’ve demonstrated that platelets take up DNA fragments that bear the mutational signatures of cancer cells,” stated a postdoctoral researcher. “This is true not only in patients with advanced cancer but, remarkably, also in people who have pre-cancerous polyps in their colon, suggesting that platelets may offer an additional and so far untapped reservoir of cfDNA that could significantly improve the sensitivity of liquid biopsies.”
How Was This Discovery Made?
The research originated from a question about how cells without nuclei could interact with DNA. Platelets possess a unique structure – a network of channels called the open canalicular system – that allows them to absorb and release various biomolecules,including viral RNA and DNA. This observation prompted a researcher to hypothesize that platelets might also be capturing genomic cfDNA during a brainstorming session organized by Cancer Research UK.
A small grant enabled the validation of this hypothesis, leading to further research and a major early detection project grant from Cancer Research UK. Researchers confirmed their findings by analyzing DNA from pregnant women carrying male fetuses, successfully predicting fetal sex based on Y chromosome fragments found within the platelets. This confirmed the platelets were indeed sequestering fetal cfDNA.
“Given their abundance, ease of isolation and tissue-wide perfusion, platelets are ideally positioned to serve as biosensors for genetic perturbations across tissues,” a senior researcher noted.
Future research will focus on understanding the physiological role of platelets in managing cfDNA and the consequences of releasing DNA fragments upon platelet activation.
The study,led by Bethan Psaila and Lauren murphy at Ludwig Oxford,with contributions from Chris Gregory at the University of Edinburgh and Benjamin schuster-Böckler at Ludwig Oxford,was published in Science on [Date of Publication – to be updated]. The research offers a compelling new avenue for improving cancer prevention and early detection strategies.
Reference: Murphy L, Inchauspé J, Valenzano G, et al. Platelets sequester extracellular DNA, capturing tumor-derived and free fetal DNA.Science. 389(6761):eadp3971. doi: 10.1126/science.adp3971.
