Stem Cells Made by Cloning Adult Humans

Two research groups have independently produced human embryonic stem-cell lines from embryos cloned from adult cells. Their success could reinvigorate efforts to use such cells to make patient-specific replacement tissues for degenerative diseases, for example to replace pancreatic cells in patients with type 1 diabetes. But further studies will be needed before such cells can be tested as therapies.

The first stem-cell lines from cloned human embryos were reported in May last year by a team led by reproductive biology specialist Shoukhrat Mitalipov of the Oregon Health & Science University in Beaverton (see 'Human stem cells created by cloning'). Those cells carried genomes taken from fetal cells or from cells of an eight-month-old baby1, and it was unclear whether this would be possible using cells from older individuals. (Errors were found in Mitalipov's paper, but were not deemed to affect the validity of its results.)

Now two teams have independently announced success. On 17 April, researchers led by Young Gie Chung and Dong Ryul Lee at the CHA University in Seoul reported in Cell...