The progress of science is paved with stories of high hopes and
heartbreaks. But in a busy lab at the University of Rochester
the two extremes have met in one dazzling yet devastating
experiment. Researchers there have for the first time
essentially cured rats of a Parkinson’s-like disease using human
embryonic stem cells. But 10 weeks into the trial, they
discovered brain tumours had begun to grow in every animal
treated. “Here we have this method that works so well to reverse
the symptoms of Parkinson’s,” said lead investigator Steven
Goldman, “But no matter how you look at it, it’s an expanding
mass and that’s bad news.” None of the cells growing out of
control were cancerous tumours. But as Dr. Goldman pointed out,
“In the brain, nothing’s benign.” read the rest of this story