Rat immune to cancer may offer medical miracle

It might not look like it can unlock the mysteries of eternal youth and with its wrinkly pink skin, beady eyes and outsize teeth, the naked mole rat resembles a sabretoothed sausage. But the strange-looking mammal has a secret which is fascinating scientists searching for a cure for diseases of old age, particularly cancer.

Despite being only four inches long, the rodent lives for 30 years – seven times longer than a normal rat – and appears not to be afflicted with the world's number one killer disease. Researchers have now taken a step towards understanding the extraordinary reason for its longevity and resistance to cancer after publishing the first draft of its complete genome.

The naked mole rat is uniquely adapted to the harsh deserts of East Africa. It lives underground, is impervious to pain and can survive despite the depleted oxygen levels in its burrows.

Dr Joao Pedro Magalhaes, who led a team at the University of Liverpool unravelling the animal's genetic blueprint, hoped one day it would provide therapies to treat conditions in humans.

"The level of resistance it has to disease, particularly cancer, might give us more clues as to why some animals are more prone to disease than others. With this work we want to establish the naked mole rat as the first model of resistance to chronic diseases of ageing," he said.

The research was carried out in partnership with the Genome Analysis Centre in Norwich and revealed the naked mole rat had a genome similar to a human, with three billion base pairs of DNA along with 20,000 proteins.

Scientists used chemical "scissors" to cut out sections of the strands of DNA, allowing them to read the sections and then put them back into the complete genome. Investigations will now focus on the DNA repair mechanisms by which cells mend themselves and protect against disease.

Bigger animals typically live longer than small animals but when researchers first studied the naked mole rat a decade ago, they noticed they just did not seem to die, said Dr Magalhaes.

Scientists in the United States began to focus on their impressive lifespan rather than the original source of interest – their curious social habits.

The naked mole rat lives in colonies of up to 300, at the centre of which is a single reproducing queen. The animals work together like a termite or wasp colony. When the female breeds, she does so with up to three mates and the rest of the males suppress their reproductive capability to allow them to concentrate on their role protecting the burrow from predators such as snakes.