Posted on 11/20/2007 7:40:45 AM PST by Pyro7480
NEW YORK - Scientists have made ordinary human skin cells take on the chameleon-like powers of embryonic stem cells, a startling breakthrough that might someday deliver the medical payoffs of embryo cloning without the controversy.
Laboratory teams on two continents report success in a pair of landmark papers released Tuesday. It's a neck-and-neck finish to a race that made headlines five months ago, when scientists announced that the feat had been accomplished in mice.
The "direct reprogramming" technique avoids the swarm of ethical, political and practical obstacles that have stymied attempts to produce human stem cells by cloning embryos.
Scientists familiar with the work said scientific questions remain and that it's still important to pursue the cloning strategy, but that the new work is a major coup.
"This work represents a tremendous scientific milestone — the biological equivalent of the Wright Brothers' first airplane," said Dr. Robert Lanza, chief science officer of Advanced Cell Technology, which has been trying to extract stem cells from cloned human embryos.
"It's a bit like learning how to turn lead into gold," said Lanza, while cautioning that the work is far from providing medical payoffs.
"It's a huge deal," agreed Rudolf Jaenisch, a prominent stem cell scientist at the Whitehead Institute in Cambridge, Mass. "You have the proof of principle that you can do it."
There is a catch. At this point, the technique requires disrupting the DNA of the skin cells, which creates the potential for developing cancer. So it would be unacceptable for the most touted use of embryonic cells: creating transplant tissue that in theory could be used to treat diseases like diabetes, Parkinson's, and spinal cord injury.
But the DNA disruption is just a byproduct of the technique, and experts said they believe it can be avoided.
The new work is being published online by two journals, Cell and Science. The Cell paper is from a team led by Dr. Shinya Yamanaka of Kyoto University; the Science paper is from a team led by Junying Yu, working in the lab of in stem-cell pioneer James Thomson of the University of Wisconsin-Madison.
Both reported creating cells that behaved like stem cells in a series of lab tests.
Thomson, 48, made headlines in 1998 when he announced that his team had isolated human embryonic stem cells.
Yamanaka gained scientific notice in 2006 by reporting that direct reprogramming in mice had produced cells resembling embryonic stem cells, although with significant differences. In June, his group and two others announced they'd created mouse cells that were virtually indistinguishable from stem cells.
For the new work, the two men chose different cell types from a tissue supplier. Yamanaka reprogrammed skin cells from the face of an unidentified 36-year-old woman, and Thomson's team worked with foreskin cells from a newborn. Thomson, who was working his way from embryonic to fetal to adult cells, said he's still analyzing his results with adult cells.
Both labs did basically the same thing. Each used viruses to ferry four genes into the skin cells. These particular genes were known to turn other genes on and off, but just how they produced cells that mimic embryonic stem cells is a mystery.
"People didn't know it would be this easy," Thomson said. "Thousands of labs in the United States can do this, basically tomorrow."
The Wisconsin Alumni Research Foundation, which holds three patents for Thomson's work, is applying for patents involving his new research, a spokeswoman said. Two of the four genes he used were different from Yamanaka's recipe.
Scientists prize embryonic stem cells because they can turn into virtually any kind of cell in the body. The cloning approach — which has worked so far only in mice and monkeys — should be able to produce stem cells that genetically match the person who donates body cells for cloning.
That means tissue made from the cells should be transplantable into that person without fear of rejection. Scientists emphasize that any such payoff would be well in the future, and that the more immediate medical benefits would come from basic research in the lab.
In fact, many scientists say the cloning technique has proven too expensive and cumbersome in its current form to produce stem cells routinely for transplants.
The new work shows that the direct reprogramming technique can also produce versatile cells that are genetically matched to a person. But it avoids several problems that have bedeviled the cloning approach.
For one thing, it doesn't require a supply of unfertilized human eggs, which are hard to obtain for research and subjects the women donating them to a surgical procedure. Using eggs also raises the ethical questions of whether women should be paid for them.
In cloning, those eggs are used to make embryos from which stem cells are harvested. But that destroys the embryos, which has led to political opposition from President Bush, the Roman Catholic church and others.
Those were "show-stopping ethical problems," said Laurie Zoloth, director of Northwestern University's Center for Bioethics, Science and Society.
The new work, she said, "redefines the ethical terrain."
Richard Doerflinger, deputy director of pro-life activities for the U.S. Conference of Catholic Bishops, called the new work "a very significant breakthrough in finding morally unproblematic alternatives to cloning. ... I think this is something that would be readily acceptable to Catholics."
Another advantage of direct reprogramming is that it would qualify for federal research funding, unlike projects that seek to extract stem cells from human embryos, noted Doug Melton, co-director of the Harvard Stem Cell Institute.
Still, scientific questions remain about the cells produced by direct reprogramming, called "iPS" cells. One is how the cells compare to embryonic stem cells in their behavior and potential. Yamanaka said his work detected differences in gene activity.
If they're different, iPS cells might prove better for some scientific uses and cloned stem cells preferable for other uses. Scientists want to study the roots of genetic disease and screen potential drug treatments in their laboratories, for example.
Scottish researcher Ian Wilmut, famous for his role in cloning Dolly the sheep a decade ago, told London's Daily Telegraph that he is giving up the cloning approach to produce stem cells and plans to pursue direct reprogramming instead.
Other scientists said it's too early for the field to follow Wilmut's lead. Cloning embryos to produce stem cells remains too valuable as a research tool, Jaenisch said.
Dr. George Daley of the Harvard institute, who said his own lab has also achieved direct reprogramming of human cells, said it's not clear how long it will take to get around the cancer risk problem. Nor is it clear just how direct reprogramming works, or whether that approach mimics what happens in cloning, he noted.
So the cloning approach still has much to offer, he said.
Daley, who's president of the International Society for Stem Cell Research, said his lab is pursuing both strategies.
"We'll see, ultimately, which one works and which one is more practical."
And how is this supposed to advance the abortion industry and its sponsor, the Democrat Party USA?
Because adult stem cells are limited in what kinds of cells they can develop into. Only way to make them totipotent is to re-program them into embryonic stem cells, which is what these researchers believe they have done, or at least come closer to doing than anyone else has so far.
Thanks for the ping, Resty! This does look like the best approach and not one frought with moral dilemma. The previous effort (ANT which is cloning purposely handicapped embryos). You have a major point with this, dear One. Again, thnaks for the ping and the reminder.
I have a problem with all of the above. I don’t believe that this should be happening at all.
However, the method of obtaining the stem cells from the article does not use an egg, and therefore there is no embryo created. The stem cells are obtained from skin cells (I think) and their DNA is reprogrammed to allow them to become any other kind of cell. There is no damaging or altering of a human zygote, only the changing of the DNA structure of an existing cell, to create a line of stem cells.
There is much work to be done, but this gives scientists an avenue to pursue another type of research, without harming embryos. I think it is excellent news.
I don’t think these are totipotent cells, as truly totipotent cells can only be derived from an embryo. These are stem cells that are deprogrammed to behave like totipotent cells. I am not sure of the technicalities, and am limited in my knowledge of genetics.
I am fairly sure that eggs are more than a convenient environment, they
are a necessary and essential part of reproduction. Without them, there can be no embryo, no fetus, and no unborn child. I think the entire point of this process is that the cells can be deprogrammed to act like the potentially beneficial embryonic stem cells, not that they have become or can become embryonic stem cells.
You have a mystical concept of cells. They are physical objects built from atoms and molecules, and can be tinkered with. If you want a cell to act like an embryonic cell, you just have to tinker with it until it has the same arrangement of atoms and molecules as a naturally occurring embryonic cell. Things are moving quickly in this field. Any details of how a given type of cell is built that are not known now soon will be.
I follow what you’re saying here, and I really hope so. Let’s keep an eye on this and related news as it comes up.
A Happy Thanksgiving to you. And thanks to God, Who is still in charge.
I understand cells, but I do not believe you can create embryonic cells without an egg. Please prove me wrong if you can, but I am relatively sure that is not possible. These stem cells are clearly made without the use of eggs, and are not embryonic. They will never create a fetus. Please provide evidence that they can, or quit passing along incorrect information. You seem to be a fan of stem-cell research of all kinds. Why do you seek to portray this information in a negative light?
Maybe they can “invest” those $6 billions in an effort to transform dead babies into adult skin cells.
The Future is Now: Stem Cell Debate Changes
Wesley J. Smith (exceedingly knowledgeable guy) calls new stem cell discoveries 'Bush's Triumph.'
So an even happier Thanksgiving for us all!
Some encouraging information:
“Richard Doerflinger of the U.S. Conference of Catholic Bishops said he was at a Vatican-sponsored meeting recently where the technique was described. “All the Catholic scientists and ethicists at the conference...had no moral problem with it at all,” he said.”
Either that, or they will cut off funding for this new technique since it is no longer a political wedge issue they can ride.
http://www.washingtonpost.com/wp-dyn/content/article/2007/11/20/AR2007112001909.html?hpid=topnews
After reading the Wesley Smith article, I found this rather contradictory article. It is WaPo so it has to be taken with a grain of salt. It does throw a wet blanket on my enthusiasm that embryonic cells were used extensively in the development of this procedure.
It now sounds like the work on these cells will be done in parallel with embryonic cells, in order to confirm that the cells actually act the same as ESCs. I have a problem with that, as it is still destroying embryos, even if the actual procedure does not use them. I find it hard to believe that the Vatican was aware of this, before they had no moral or ethical objection.
I am wondering about your opinion.
There’s no way Vatican science advisors would OK research that kills embryos. Therefore I have to assume that they were commenting on the work done with reprogrammed cells themselves, and not parallel work done which destroys early-stage human beings.
Doerflinger is the most reliable man on the planet on this subject, IMHO. I used to work for him in 1986-87, and he’s that unusual combination, smart (really smart) and good (really good).
If cells have all the therapeutic and research potential of embryonic stem cells, i.e. can be coaxed into becoming any type of cell or organ, then they also have the ability to develop into a whole organism. If they don’t have the ability to develop into a whole organism, then they will also lack much of the therapeutic capacity of embryonic stem cells. These researchers are not claiming to have gotten all the way there, but are claiming to have gotten a lot closer than anyone has before, and to have developed techniques which will allow them to fully reprogram cells to an embryonic and still dividing state. Perfecting the techniques to the point where stem cells of true embryonic origin wouldn’t have any significant advantage over the “de-programmed” cells would mean they have ALL the capacities of embryonic cells. If they add some special trick to prevent otherwise fully re-programmed cells from having the ability to become viable embryos, then that will have been a specific intentional act aimed at preventing viability in an embryo that otherwise would be viable — hardly much of a ethical distinction from simply rendering a viable embryo non-viable.
Just as you can pluck a pair of cells off an early stage embryo and have them continue developing and produce a whole organism (which has been done commercially for decades with cattle, and can presumably done with humans too, since splitting embryos is how identical twins arise), cells that have been FULLY reverse engineered to be identical to embryonic cells can do the same thing. Because it hasn’t quite been done yet is hardly evidence that it can’t be. Until this latest development, adult cells “couldn’t” be reprogrammed to this near-embryonic state that has now been achieved.
Egg cells don’t occupy some special category with different rules than other cell types. They spring forth from the same DNA that directs production of all other cell types and of whole organisms. What has already been done in mice is to develop immature egg and sperm cells from embryonic stem cells, with sperm cells capable of fertilizing an egg. In vitro maturation of human egg cells for fertility treatment is on the verge of being applied in clinical practice. Soon the two processes will be combined.
I don’t know why you think I’m portraying this announcement in a negative light. I think it’s great that they’ve done this and hope they can perfect the process quickly so that therapeutic applications using cells genetically matched to patients can be developed as soon as possible. I don’t regard any clump of totipotent or pluripotent cells as a person, so it doesn’t bother me a bit that they will soon be making viable embryos that are genetic matches to patients, and steering those embryos down a different course of development to obtain specific cells or organs needed for treatment.
So what I now understand about your posts is that you are not speaking at all to this most recent discovery, but rather to a potential future discovery??
You refer to the possibility that these cells will be completely reprogrammed in the future so that eggs are no longer used in reproduction. While nothing is out of the realm of possibility, I don’t think we are as close to this possibility as you do. Making babies out of skin cells is still in the realm of science fiction, and I hope that it stays that way.
If this discovery actually has the great significance for future stem-cell based research and therapies that is the basis for all the hoopla surrounding the announcement, then this discovery has made the same degree of progress towards producing viable embryos as towards producing new stem-cell based treatments that had previously been believed to be unachievable without using originally embryonic stem cells.
The origin of germ cells — i.e. sperm and egg cells — from embryonic cells occurs very, very early in embryonic development. It is therefore highly unlikely that a cell that has been been de-programmed, but not far enough back to produce germ cells, would have the capacity to produce an unlimited variety of other cell types. That’s such a critical differentiation process that it’s not located off on some minor tangent; IOW a cell that couldn’t do that would be a seriously defective embryonic cell lacking other key capabilities as well. And if it IS far enough back in the differentiation process to produce germ cells, it’s so close to a completely undifferentiated embryo that it’s very unlikely not to retain the capacity to develop into a full organism. Most identical twin humans arise at the blastocyst stage, which is after differentiation into at least 2 cell types has occurred, so at least through that stage, complete new organisms easily arise. In other words, you wouldn’t even need to de-program cells all the way back to the stage of a 4-8 cell embryo (i.e. totally undifferentiated) in order for them to produce viable embryos.
“Both studies used reprogramming of adult human cells to generate stem cells known as “induced pluripotent state cells” (iPSCs) that have all the properties of human embryonic stem cells.”
Source:http://article.nationalreview.com/?q=NDVlNDBkYmE5YTUxODU2ZWFkOGUxMmY3NTNiNTk2ZmU=
Notice that these are not totipotent, nor do they require an egg. Pluripotent cells can not develope into a fetus. There is nothing in this process to indicate anything you have said, and you have provided no evidence for anything you say.
Just because someday a process might be created that can take this process further, and there is a slight possibility that embryos might someday be created through a similar process does not make it likely or relavent. It would appear that you are trying to antagonize those who believe that an embryo is a human life. Maybe you could write a nice fictional story about this new process you are so knowledgeable about. I am interested in the process described in this article, not some wild idea you have about the future of genetics.
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