George Dvorsky in io9:
Scientists from Stanford Medical Center have devised a technique for extending the length of human telomeres. It's a breakthrough that could eventually result in therapies to treat a host of age-related diseases, including heart disease and diabetes. It could also result in longer, healthier lives.
Telomeres are those critical protective caps located on the tips of chromosomes. Think of them as those protective pieces of plastic on the ends of your shoelaces. Without them, the tips basically fall apart, which is kind of what happens with chromosomes over time; human telomeres, which are about 8,000 to 10,000 nucleotides long, get shorter and shorter with each cell division. Over time, they reach a critical length, and the cell stops dividing, or simply dies. At the macroscale, we experience this as senescence, or aging, as your body's cells progressively lose the ability to replenish.
So you can see why this breakthrough, in which the Stanford scientists rapidly and efficiently increased the length of human telomeres, is big news.
To do it, a research team led by Helen Blau delivered a bioengineered version of messenger RNA that encodes a telomere-extending protein to cultured human cells. In this case, the RNA contained a coding sequence called TERT, which is the active component of telomerase.