Gene therapy `extends mice lifespan by up to 24 pc`
London: In a pioneering experiment, Spanish scientists claim to have extended the lifespan of ageing mice by up to 24 per cent, using a single gene therapy treatment.
If this research pays off, then things are looking up for ageing humans too, says a team at the Spanish National Cancer Research Centre which has published its findings in the `EMBO Molecular Medicine` journal.
Earlier studies have shown that it is possible to lengthen the average life of individuals of many species, including mammals, by acting on specific genes -- an approach impracticable in humans.
Now, the Spanish scientists, led by Maria Blasco, have demonstrated that the mouse lifespan can be extended by the application in adult life of a single treatment acting directly on the animal`s genes.
And they have done so using gene therapy, a strategy never before employed to combat ageing. The scientists induced cells to express telomerase -- the enzyme which metaphorically slows down the biological clock.
The therapy has been found to be safe and effective in mice, say the scientists.
In fact, in their experiment, the scientists treated adult mice (one-year-olds and two-year-olds), with the gene therapy delivering a "rejuvenating" effect in both cases. Mice treated at age of one lived longer by 24 per cent on average, and those treated at two, by 13 per cent.
The therapy, furthermore, produced an appreciable improvement in the animals` health, delaying the onset of age- related diseases like osteoporosis and insulin resistance and achieving improved readings on aging indicators like neuromuscular coordination.
The gene therapy consisted of treating the animals with a DNA -- modified virus, the viral genes having been replaced by those of the telomerase enzyme, with a key role in ageing.
Telomerase repairs the extreme ends or tips of chromosomes, known as telomeres, and in doing so slows the cell`s and therefore the body`s biological clock. When the animal is infected, the virus acts as a vehicle depositing the telomerase gene in the cells.
"This study shows that it is possible to develop a telomerase-based anti-ageing gene therapy without increasing the incidence of cancer," said the scientists.
"Aged organisms accumulate damage in their DNA due to telomere shortening, [this study] finds that a gene therapy based on telomerase production can repair or delay this kind of damage," they added.