New Scientist
Image: Nomad Tales
After a nuclear meltdown, exposure to DNA-damaging radiation levels can happen in minutes – but accessing therapies that might combat the effects can take days. A new drug could help: in mice, it reduced death rates from radiation sickness even if given three days after exposure. It may one day protect astronauts heading for Mars from harmful cosmic rays.
Cells try to repair damage to their DNA after radiation exposure, says Gábor Tigyi at the University of Tennessee Health Science Center in Memphis, but the process isn’t foolproof. If the cell doesn’t recognise the errors left in its DNA it might ultimately turn cancerous. But if the cell does recognise the errors the outcome is even worse: it will self-destruct, and if enough cells follow that route, death will follow within weeks.
Tigyi and his colleagues have spent 10 years exploring the power of lysophosphatidic acid (LPA), a naturally occurring signalling molecule that seems to give cells a better chance against radiation exposure. Through a mechanism that remains unclear, LPA can buy the cell more time to repair its DNA, says Tigyi. “Our data also show that LPA has the ability to enhance the repair process and potentially increase its fidelity,” he says – which means more cells are saved from turning cancerous or self-destructing.
