WASHINGTON – Harvard scientists announced they've discovered a way to fuse adult skin cells with embryonic stem cells (search), a promising breakthrough that could lead to the creation of useful stem cells without first having to create and destroy human embryos.
The scientists said they were able to show in their early research that the fused cell "was reprogrammed to its embryonic state." Such a breakthrough could have the effect of taming a biting national debate about the ethics of stem-cell research, but not any time soon.
"If future experiments indicate that this reprogrammed state is retained after removing the embryonic stem cell DNA — currently a formidable technical hurdle — the hybrid cells could theoretically be used to produce embryonic stem cells lines that are tailored to individual patients without the need to create and destroy human embryos," said a summary of the research reported on the Science journal (search) site.
Researcher Kevin Eggan stressed, however, that the technology is preliminary.
"I can't stress enough that this technology is not ready for prime time right now," Eggan said at a briefing Monday. "It is not a replacement for those techniques that we already have for derivation of embryonic stem cells."
"This is the first step down a long and uncertain road," said Eggan, noting that it comes with its own set of limitations.
It could easily be 10 years before the process is usable in people, he said.
Eggan said, "There are still fundamental biological hurdles that have to be overcome."
The goal is to make stem cells that carry a patient's genes, and only the patients genes, he said. The cells created in this process carry too much DNA (search), both that of the stem cell and that from the embryonic stem cell used in the process.
The new process still involves use of an embryonic stem cell, but the researchers hope it will tell them how an adult cell can be reprogrammed into an embryonic stem cell without use of embryonic cells to begin with.
"There are groups of people in the U.S. and elsewhere who feel it's fundamentally wrong to destroy early state [stem cells]," he said. Learning how the adult cell is changed might lead to a way around that concern, Eggan said.
The researchers used laboratory grown human embryonic stem cells — such as the ones that President Bush has already approved for use by federally funded researchers — to essentially convert a skin cell into an embryonic stem cell itself.
If a number of hurdles can be overcome in subsequent research, the new technique "may circumvent some of the logistical and societal concerns" that have hampered much of the research in this country, Chad A. Cowan, Eggan and colleagues from the Harvard Stem Cell Institute (search) reported in the Science article.
Those social concerns are reflected in the Senate's looming debate over a House-passed bill to force taxpayers to fund stem cell research that would destroy human embryos, legislation that Bush has promised to veto.
Bush and many fellow conservatives believe it is immoral to create embryos only to destroy them, even in the name of scientific progress that could cure or treat diseases afflicting millions of people.
Debate and a vote on the bill will proceed next month as planned, Senate Majority Leader Bill Frist's spokeswoman, Amy Call, said Monday. Frist earlier this month said he will vote for the bill, widely expected to pass even in the face of Bush's veto threat.
The hybrid cells created by the Harvard team "had the appearance, growth rate, and several key genetic characteristics of human embryonic cells," the summary of their work said.
"They also behaved like embryonic cells, differentiating into cells from each of the three main tissue types that form in a developing embryo," it said.
The authors conclude that human embryonic cells have the ability to reprogram adult cell chromosomes following cell fusion.