A single protein could be a key to extending the normal lifespan of worms and possibly even humans, Swiss scientists said on Wednesday.
By knocking out a protein called TOR that regulates cell growth in the nematode worm, or C. elegans, researchers at the University of Fribourg, in Switzerland discovered they could extend its lifespan from 15 to 25 days.
"It has been suggested that maybe TOR could have an influence on ageing. We have proven it for the first time in C. elegans," Professor Fritz Muller, who headed the research team, told Reuters.
"It is very likely that we may find similar things in other species as well but it remains to be proven."
The protein, which is present in plants, animals and humans, regulates metabolism and energy. It senses the availability of nutrients and translates that into protein synthesis and cell growth.
Scientists have shown that drastically reducing calories in mice and other rodents extends their lifespan. Muller and his colleagues believe TOR could be the link to explain how it happens.
"TOR senses the amount of food available. If there is a lot of food TOR expression is high. Protein synthesis is high, cell division, everything is high," said Muller, who reported his findings in the science journal Nature.
But if there is no food, TOR activity is low.
"We have shown that if you reduce TOR activity artificially or even knock it out you enhance longevity. That is the way food may be linked to longevity. No food, low food, TOR goes down and age (longevity) goes up," he added.
The researchers suspect the protein interacts with other cell signalling pathways in the body to regulate cell growth.
Although the mice without TOR lived nearly twice as long as normal mice, Muller said they were less fertile. The scientists also noticed changes in their metabolism.
"The worm has to pay something for living longer," said Muller.
He added that TOR is also being discussed as a possible drug target against cancer. Because cancer cells grow rapidly and TOR controls protein synthesis and cell growth, it is thought that knocking out or inhibiting TOR could slow the growth of the diseased cells.