WORCESTER, Mass. -- Scientists reported today a way to extract an embryonic stem cell from a human embryo without damaging it, a finding that may ease the rancorous debate over such research.
WORCESTER, Mass. Aug. 24 -- Scientists reported today a way to extract an embryonic stem cell from a human embryo without damaging it, a finding that may ease the rancorous debate over such research.
The procedure uses a single-cell biopsy similar to that used in pre-implantation genetic diagnosis, according to Robert Lanza, M.D., of Advanced Cell Technology of Alameda, Calif. The research was carried out at the company laboratory here.
"There is no harm to the embryo that we're biopsying," Dr. Lanza said in a statement. Indeed, he noted, more than 1,500 healthy children have been born from embryos that have undergone a pre-implantation genetic diagnosis procedure.
Essentially, Dr. Lanza and colleagues reported in the Aug. 24 issue of Nature, the procedure adds a step to the diagnostic procedure. Instead of being taken directly for genetic analysis, the single cell removed from the eight-cell embryo is cultured overnight.
The resulting cells can be used both for pre-implantation genetic diagnosis and to create stem cell lines, Dr. Lanza said.
The clinical potential of human embryonic stem cell research is regarded as vast, but actual therapies are rare, possibly because the relatively limited number of cell lines available for experiment, especially in the U.S., makes it difficult to study them.
The new technique could alleviate that shortage, Dr. Lanza said, and allow researchers to forge ahead in finding ways to use stem cells to create tailored tissues for a host of therapeutic purposes.
One immediate implication is that matched tissue could be available for children born after a pre-implantation genetic diagnosis procedure and for their siblings, the researchers said.
In the experiments reported in Nature, the researchers were able to develop two stable human embryonic stem cell lines that were karotypically normal and able to grow for more than eight months without differentiating into other cell types.
The cells also expressed molecular markers of the ability to differentiate into other cell types and when stimulated were able to form cells typical of all of the three embryonic germ layers, both in vitro and in teratomas.
"It appears that these cells are absolutely identical to all the human embryonic stem cells we have in the lab," Dr. Lanza said.
Current methods for the deriving hES cell lines relies on fishing the parent cells out of the inner cell mass of blastocysts, destroying their ability to develop further -- a fact that has been at the heart of the debate over human embryonic stem cells.
"The ability to create new stem cell lines and therapies without destroying embryos would address the ethical concerns of many," Dr. Lanza and colleagues said.