Drug 'could block radiation damage'

10 April 2008 12:00am

A drug has been tested that could protect against the fall-out from a "dirty bomb" terrorist attack or nuclear disaster.

The drug, which blocks radiation damage to the body, also has the potential to make radiotherapy cancer treatments safer and more effective.

Known as CBLB592, it switches on a biological mechanism that helps healthy cells survive blasts of radiation.

But it does not appear to have the same effect on normal tumours, which remain vulnerable.

Radiation kills cells indirectly, by turning on a cell suicide programme called apoptosis. Its purpose is to wipe out cells with damaged DNA before they turn cancerous.

Tumour cells and healthy cells alike may be destroyed by this process. When therapeutic doses of radiation are used to treat cancer, healthy cells eventually recover while cancer cells perish.

However in some cases resistant cancer cells are able to block apoptosis and withstand radiotherapy. Many researchers are looking at ways of triggering cell suicide artificially to fight cancer.

But US scientists led by Dr Lyudmila Burdelya, from the Roswell Park Cancer Institute in Buffalo, New York, took the opposite approach. They wanted to see if apoptosis could be turned off in a controlled way to protect against radiation.

CBLB502 is a drug that inhibits the protein which kick-starts cell suicide at the genetic level.

The drug significantly reduced radiation damage to bone marrow and gastrointestinal cells. When tested on mice with cancer, it protected healthy tissue while not interfering with the death of tumours.

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