Parasitic DNA proliferates in aging tissues
As mice age, cells in tissues such as the liver and skeletal muscle lose control over rogue sequences of DNA called “retrotransposable elements,” according to new research in the journal Aging. The elements, which may undermine health, could proliferate in old mice and were also abundant in cancerous tissue. A low-calorie diet, however, restrained their advance.
PROVIDENCE, R.I. [Brown University] — The genomes of organisms from humans to corn are replete with “parasitic” strands of DNA that, when not suppressed, copy themselves and spread throughout the genome, potentially affecting health. Earlier this year Brown University researchers found that these “retrotransposable elements” (RTE’s) were increasingly able to break free of the genome’s control in cultures of human cells. Now in a new paper in the journal Aging, they show that RTEs were increasingly able to break free and copy themselves in the tissues of mice as the animals aged. In further experiments the biologists showed that this activity was readily apparent in cancerous tumors, but that it also could be reduced by restricting calories. (more…)