Junk DNA may be dangerous, study says
FRIDAY, Aug. 9, 2002 (HealthDayNews) -- Junk DNA might be more than just genetic trash -- it could be dangerous.
University of Michigan Health System scientists report the troubling finding in today's issue of Cell.
They discovered that in cultured human cancer cells, segments of junk DNA called Line-1 (L1) elements can delete DNA when they jump to a new location. In doing so, these L1 elements may knock out genes or create mutations.
"The value of this study is the unexpected knowledge that Line-1 elements have the potential to cause broad-spectrum mutations in individual tumor cells," says John V. Moran, an assistant professor of human genetics and internal medicine at the university.
He says these L1 elements make up 17 percent of human DNA.
"Of 37 transposable events in our study, four resulted in deletions of genetic material," says study co-author Nicolas Gilbert, a post-doctoral fellow in human genetics.
"In cultured cells, we know that L1s can add to the genome by increasing its size, and now we've learned that they can decrease genome size by deleting genetic material," says study co-author Sheila Lutz-Prigge, a research associate.
"But we have no control over the size or location of the deletion, and we don't yet know how often it occurs in humans," she says.
For more on junk DNA, go here.