Genetic abnormalities found in stem cell lines

By Eryn Brown
January 6, 2011, 1:27 p.m.

People have pinned a lot of hopes on pluripotent stem cells -- which, because of their amazing capacity to morph into other types of cells, have been touted as a potential source for replacement tissues that might someday help reverse spinal cord injuries, Alzheimer's disease, and even the damage caused by heart attacks.

But so far only two companies have been granted permission by the Food and Drug Administration to move ahead with trials in humans -- Geron Corp., which is testing a treatment for spinal cord injury; and Advanced Cell Technology, which is testing a treatment for macular degeneration.

A new study, published Thursday in the journal Cell Stem Cell, may illustrate part of the reason why. Scientists still haven't figured out how to make sure most stem cells are safe, and won't develop into cancer once implanted in patients.