The scientists said their early research shows that the fused cell "was reprogrammed to its embryonic state," reported the Associated Press. Such a breakthrough could eventually help defuse the bitter debate surrounding the ethics of embryonic stem cell research.
According to the journal Science: "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."
One of the lead researchers, Kevin Eggan, emphasized that the research is in the beginning stages.
"I can't stress enough that this technology is not ready for prime time right now," he said at a briefing Monday, according to the AP. "It is not a replacement for those techniques that we already have for derivation of embryonic stem cells."
He said it could be 10 years before the process is usable in people.
"There are still fundamental biological hurdles that have to be overcome," he added.
The goal is to create a stem cell that carries only the patient's DNA. The cells created in the process announced Monday carry the DNA of the stem cell and the embryonic stem cell used in the process, Eggan said.
Although the research involves the use of embryonic stem cells, the scientists said they hope it will tell them how an adult stem cell can be reprogrammed into an embryonic stem cell.
The researchers used laboratory grown human embryonic stem cells, such as the ones President Bush has already approved for use by federally funded researchers, to convert a skin cell into an embryonic stem cell itself, reported the AP.
The hybrid cells created by the Harvard Medical School team "had the appearance, growth rate and several key genetic characteristics of human embryonic cells," according to a summary of the team's work.
Doctors hope to someday use embryonic stem cells as a source of perfectly matched transplants to treat diseases such as cancer, Parkinson's and some injuries. However, some people object to the destruction of and experimentation on human embryos.