SCIENTISTS IN the US have successfully tested a drug that can protect cells against damage caused by nuclear radiation. The discovery has the potential to transform radiation treatments used against cancer, but could also help protect the public after a nuclear accident or "dirty bomb" terrorist attack.
The drug, CBLB502, has been tested on mice and rhesus macaque monkeys with startlingly good results. The drug saved 87 per cent of mice exposed to high doses of radiation that would otherwise have killed them. And the drug afforded protection even if given after exposure, saving 40 per cent of mice where only 7 per cent would have survived without the drug.
Importantly for its potential use in radiation oncology, the drug protected healthy cells but left cancer cells just as sensitive and susceptible to radiation exposure. Four centres in the US collaborated in the research, published this morning in the leading journal, Science.
The scientists took a lead from nature in trying to "pharmacologically mimic" a process often used by tumour cells to evade normal cell death. Natural cell death or apoptosis is a highly regulated process essential for life. Cancer cells can become immortal by switching off apoptosis, allowing them to grow uncontrollably.
The new drug stimulates a signalling point on cells known as TLR5, which in turn activates a protein called NF-kappaB, the researchers explained.
This protein creates a chain reaction that temporarily blocks the process of apoptosis. It allows the cells to survive the radiation onslaught."CBLB502 treatment completely prevented radiation-induced mortality or significantly protected against radiation-induced mortality but had no radioprotective effect on the tumours," the authors report.