Scientists have succeeded in reprogramming ordinary cells from the tips of mouse tails and rewinding their developmental clocks so they are virtually indistinguishable from embryonic stem cells, according to studies released Wednesday.
If the discovery applies to human cells – and researchers are optimistic it will – it would offer a straightforward method for creating a limitless supply of cell lines tailor-made for patients without any ethical strings attached.
Three research groups said they accomplished their feat by activating four genes that are turned on in days-old embryos. Some of the rejuvenated cells grew into new mice, demonstrating the cells’ ability to create every type of tissue in the body.
“This is truly the Holy Grail – to be able to take a few cells from a patient, say a cheek swab or some skin cells, and turn them into stem cells in the laboratory,” said Dr. Robert Lanza, an embryonic stem-cell researcher at Advanced Cell Technology Inc. in Worcester, Mass., who was not involved in the research. “It would be like turning lead into gold.”
Massachusetts Institute of Technology biologist Rudolf Jaenisch, who worked on two of the studies, said there are still “lots and lots of technical hurdles to overcome.” But if those hurdles are cleared, reprogrammed cells could become the long-sought substitute for embryonic stem cells.
President Bush and other social conservatives have long opposed human embryonic stem- cell research because the cells can be obtained only by destroying embryos.
Government funding of such research is a top political issue in Washington. The House is scheduled to vote today on a bill sponsored by Rep. Diana DeGette, D-Colo., that would lift Bush’s restrictions on funding of embryonic stem-cell research.
“We expect to pass this important bill again with a broad, bipartisan majority,” DeGette said Wed nesday. “Both the majority of Congress and the American people support this promising research. The only person standing in its way is a stubborn president.”
Bush has said he will veto the measure, as he did last year when it passed Congress.
Reprogrammed cells could allow scientists to sidestep the ethical dilemmas surrounding therapeutic cloning, in which scientists seek to create a human embryo that is genetically identical to a sick patient by inserting the patient’s DNA in an unfertilized egg.
The resulting stem cells harvested from the embryo could theoretically be used to generate neurons for patients with Parkinson’s disease or insulin-producing cells for diabetics without running the risk of tissue rejection.
Stem cells derived from reprogrammed cells would allow scientists to create genetically matched tissues without having to destroy a cloned embryo.
Denver Post staff writer Anne C. Mulkern contributed to this report.
