U.S. company says grows embryo-safe stem cells

By Maggie Fox, Health and Science Editor

WASHINGTON (Reuters) - Researchers at a U.S. company trying to push the margins of stem cell research said on Friday they had grown human embryonic stem cells using a non-controversial method that did not harm the embryos.

They said they had grown several lines, or batches, of the cells using a single cell taken from an embryo, which they then froze unharmed.

"We generated three new lines," Dr. Robert Lanza of Advanced Cell Technology Inc. told Reuters.

"These are first human embryonic cell lines in existence that didn't result from the destruction of an embryo."

Lanza gave a brief summary of the work to a meeting of the International Society for Stem Cell Research in Cairns, Australia this week. He plans to publish details in a medical journal.

ACT hopes the approach might bypass objections to human embryonic stem cell research. U.S. President George W. Bush vetoed a bill this week that would have broadened federal funding of such work.

Researchers say these cells, taken from days-old embryos, might provide a way to regenerate all sorts of tissues, blood and perhaps even organs. And studying them might help them learn how to reprogram ordinary cells.

Some countries, such as Britain, encourage this work. But opponents such as Bush say it is immoral to destroy a human embryo.

Last year, Lanza's team reported they had derived stem cells from a human embryo by taking just one cell at a time.

In theory, this would be the same as is done already in some fertility clinics when parents get embryos tested for genetic defects so they can conceive children free of diseases such as cystic fibrosis.

HEALTHY BABIES

This method, called pre-implantation genetic diagnosis or PGD, has been shown to be safe, with healthy babies born after it is performed.

But Lanza said he did not want to waste any embryos, so he in fact used more than one cell from the embryo for his experiment last year, destroying the embryo. Critics of human embryo research denounced his work.

This time, his team used just a single cell from each of three embryos and then froze the embryos. "These embryos remain frozen. They are still alive," Lanza said.

One contains a genetic defect that will doom it, called trisomy 16. "Those embryos can never go past the first trimester. Even if the embryo were implanted it could not give rise to a viable child," Lanza added.