That's an interesting finding, though it's not clear to me how one would be able to destroy senescent cells without damaging cells that are still functioning normally.
Cellular senescence has long been thought to be a central factor of aging and death. There's a field of longevity research called SENS (Scientifically Engineered Negligible Senescence) which seeks ways to allow cells to continue to function normally indefinitely. Cellular senescence seems to be closely related to the fact that cells can only reproduce a certain number of times before the DNA in them is damaged to the point where the cell can't reproduce; the end caps on the genes, called "telomeres," shorten each time the cell divides, and when the telomeres become short enough, the cell can no longer divide.
Imortal cells, like single-celled organisms, produce an enzyme called telomerase which repairs the telomeres. Human and mammal cells don't generally produce telomerase, though cancer cells do. (Cancer cells usually have DNA that is radically different from the host organism; a cell that has gone cancerous typically has DNA that has been so badly damaged that a cancer tumor in a person might not even have the same number of chromosomes as the person does.) The fact that our cells have this limit on the number of times they can divide appears to be a defense against cancer, though the cost of that defense is a finite lifespan.
