Stem cells come from human skin

In breakthroughs that burst like bombshells in biology’s hottest field, rival scientists in Japan and the United States have announced that they successfully turned human tissue into cells that behave like embryonic stem cells — potentially medicine’s most powerful weapon against an array of deadly diseases.

The research seems certain to accelerate the pace of stem cell research. By using a simple recipe of four genes to “reprogram” ordinary adult skin cells into an embryonic state, the new processes bypass the ethical, religious, and political objections to creating — and destroying — cloned human embryos from which to cull the precious stem cells, which until now most scientists had seen as the most realistic method, reports the Boston Globe.

The ground-breaking work at Kyoto University and the University of Wisconsin-Madison also could lead the Bush administration to re-think its virtual ban on funding for embryonic stem cell research, perhaps opening the money spigots to at least those labs limiting themselves to researching stem cell batches, called lines, derived using the new procedures from cells acquired with cheek swabs or other such mundane means.

Stem cell scientists around the world hailed the work in humans as revolutionary.

“It’s a bit like learning how to turn lead into gold,” said Robert Lanza, chief scientific officer for the Massachusetts-based research firm Advanced Cell Techology. “If perfected, there will no longer be any need for human eggs [in stem cell research], or any of the controversy associated with destroying embryos.”

He stressed, however, that “this is early stage research, and that we should not abandon other areas of stem cell research.”

Shinya Yamanaka, the Kyoto researcher who earlier this year triggered a tsunami of excitement by forging functional embryonic-like stem cells from the tails of lab mice, accomplished his latest feat by using a potent cocktail of four genes that, when inserted into adult human skin cells, effectively turns back the clock and causes the tissue to regress to a stem-cell stage. The research was published today in the journal Cell.

University of Wisconsin scientists, in a near dead-heat finish with Yamanaka’s team, also announced the reprogramming of adult human tissue into embryonic-like stem cells. They used a similar process, but a different combination of genes, or “transcription factors,” that control the activity of other genes.

The Wisconsin results, which lent greater strength to Yamanka’s research because the work was accomplished by more than one team, will be published Thursday by the journal Science.

“The induced cells do all the things embryonic stem cells do,” said James Thomson, a stem cell pioneer who oversees the University of Wisconsin lab where scientist Junying Yu led the revolutionary research. “It’s going to completely change the field.”
There were plenty of hurrahs. But you could almost hear the gnashing of teeth in top research centers in Cambridge, Boston, and beyond, where teams of scientists had been closing on similar results.

“There’s been a real race, and the competion has been intense, and this research represents a huge ‘first’ in a critically important area,” said Leonard I. Zon, head of the stem cell research program at Children’s Hospital Boston. “This is work of tremendous significance that is going to open a lot of doors in biology and medicine.

“But it doesn’t mean the larger race is over,” Zon said. “Enormous new discoveries are waiting in the field.”

In fact, however, the new discoveries could dramatically alter the field. Proof that cells with the capabilities of embryonic stem cells can be engineered from adult tissue could eventually spell doom for controversial research at Harvard and other top centers focusing on creating embryonic stem cell lines from cloned embryos.

The cells made in the labs in Kyoto and Madison, called induced pluripotent stem cells, appear to function more or less the same as true embryonic cells, seemingly capable of replicating themselves endlessly and producing any of the 220 more specialized cells that form the body’s blood, tissue, and organs. Still, these are early days and there are potential pitfalls.

It may prove in the long term, for example, that embryonic cloning — for all its controversy — yields purer, more “natural” stem cells than those engineered from adult cells using genes associated with cancer, tricky retroviruses, and other genetic materials that are employed in the new research.

“What patients need is the fastest, most effective way forward,” said Douglas Melton, co-director of the Harvard Stem Cell Institute. “Until the alternative [approach] is shown to produce the same kind of extremely versatile, normal cells that we derive from previously frozen human blastocysts, it would be unfair to patients to renounce” use of embryonic clones for stem cell research.

Stem cells are thought to hold extraordinary potential for medical research and eventual therapies for an array of lethal ailments, ranging from Parkinson’s disease to severed spinal cords. Stem cells made from a patient’s own body might be used to create new genetically identical tissue — heart cells, nerve cells, liver cells, and so on — to repair, say, diseased hearts or the ravages of juvenile diabetes.

“From skin cells in a single 10-centimeter lab dish, you can get multiple [stem cell] lines,” Yamanaka said from Kyoto.

Opponents and critics of stem cell research involing cloned human embryos were quick to hail the new methods. Said Rev. Tadeusz Pacholczyk, spokesman for the National Catholic Bioethics Center: “This breakthrough effects the ethical discussion in a very positive way. These new strageies remind us … it is never necessary for laboratory researchers to cross fundamental lines in order for science and medicine to advance.”

Scientifically, it appears that reprogramming techniques may speed forward stem cell research by years, even decades — only last summer, researchers were predicting that the forging of human stem cells from adult tissue lay somewhere in the far future.

Most stem cell scientists had believed that the cloning of human embryos through a process know as somatic cell nuclear transfer represented the best bet for producing useable human embryonic stem cells in the next five- or 10 years.

Comments are closed.