PopSci Predicts: The Year Ahead

Stem Cells Grow Up

New research into adult cells may reenergize therapeutic research

The promise remains tantalizing: radical new treatments for diabetes, Parkinson´s disease and even cancer enabled by stem cells-self-renewing bodies capable of differentiating into other, more specialized cell types. Progress, however, has been achingly slow. The California Institute for Regenerative Medicine, which administers the state´s $3-billion stem-cell-research initiative, estimated in October that fully developed stem-cell therapies are still more than a decade out.

Why the wait? Scientists need a far deeper understanding of cell biology, where the bulk of research will be focused for years. And even that task is hindered by laws proscribing the use of human embryonic-stem-cell lines in federally-funded labs.

Small wonder, then, that the most enticing developments are coming from research on adult stem cells-a twist that could render moot the moral objections associated with the use of embryonic cells. Adult stem cells, which regularly repair or replace damaged cells, have been hard to morph into other types of tissue. But that´s changing. Last year, researchers at UCLA transformed adult stem cells in fat tissue into muscle cells, a development that could aid in repairing arteries and bladders.

Even more groundbreaking was the work by two scientists at Kyoto University in Japan who reported last August that they had induced embryonic stem cells from adult skin cells in mice tails. They first isolated four genes present in embryonic cells but inactive in adults. When adult cells received chemical factors from those four genes, they reverted into embryonic cells that could differentiate into any tissue. If the Kyoto research is replicated in humans, it will be a game-changer for the science. â€Let´s say you could take your skin cells and reprogram the nucleus to create an embryonic-stem-cell line-without an egg,†says the California Institute´s Mary Maxon. â€Therapeutically, that would be huge.†-Kevin Kelleher