Human Embryos Cloned From Skin Cells

Jan. 17, 2008 -- Scientists say they have produced embryos that are clones of two men, a potential step toward developing scientifically valuable stem cells.

It's the first documented demonstration that ordinary cells from an adult human can be used to make cloned embryos mature enough to produce stem cells, the researchers said. But because they haven't produced those stem cells yet, experts reacted coolly.

Since other scientists had previously made a cloned human embryo, "I found it difficult to determine what was substantially new," said Doug Melton of the Harvard Stem Cell Institute.

He said the "next big advance will be to create a human embryonic stem cell line" from cloned embryos. "This has yet to be achieved," Melton said.

Korean scientist Hwang Woo-suk claimed a few years ago that he'd created such cell lines, but that turned out to be a fraud.

Samuel Wood, a co-author of the new paper and chief executive of Stemagen Corp. of La Jolla, Calif., said he and his colleagues are now attempting to produce stem cell lines from the embryos.

The work was published online Thursday by the journal Stem Cells.

Scientists say stem cells from cloned embryos could provide a valuable tool for studying diseases, screening drugs and, perhaps someday, creating transplant material to treat conditions like diabetes and Parkinson's disease.