Archive for July, 2009
Researchers May Have Found Equivalent of Embryonic Stem Cells
By Rob Stein, WashingtonPost.com
Chinese scientists have bred mice from cells that might offer an alternative to human embryonic stem cells, producing the most definitive evidence yet that the technique could help sidestep many of the explosive ethical issues engulfing the controversial field but raising alarm that the advance could lead to human cloning and designer babies.
In papers published online Thursday by two scientific journals, separate teams of researchers from Beijing and Shanghai reported that they had for the first time created virtual genetic duplicates of mice using skin cells from adult animals that had been coaxed into the equivalent of embryonic stem cells.
The findings were welcomed by supporters and opponents of human embryonic stem cell research as a long-sought vital step in proving that the cells could be as useful as embryonic cells for studying and curing many illnesses.
The results come just as the Obama administration has eased federal restrictions on government funding for embryonic stem cell research, and they could influence how to prioritize millions of dollars in new spending in the field.
But because of concerns that the techniques might make cloning and genetic engineering of embryos easier, the work could reignite calls for a ban on attempts to clone people and for restrictions on genetic manipulation of embryos.
“The implications of this are both enormously important and troublesome,” said Robert Lanza, a stem cell researcher at Advanced Cell Technology in Worcester, Mass. “It revives many of the issues raised by reproductive cloning.”
Many scientists believe human embryonic stem cell research could revolutionize medicine by enabling doctors to use genetically matched tissue to treat many diseases. But the field has been mired in controversy because embryos are destroyed to obtain the cells.
In 2006, scientists discovered that they could induce adult cells to regress to a stage that appeared identical to embryonic stem cells, called induced pluripotent stem (iPS) cells. Although scientists have become increasingly adept at creating and manipulating such cells, questions have lingered about whether they are truly equivalent. The new experiments were designed to put the cells to what has long been considered the most rigorous test.
In the studies, published in the journals Nature and Cell Stem Cell, the researchers used viruses to flip genetic switches in the DNA of skin cells from adult mice to turn them into iPS cells in the laboratory. The researchers then injected some of the iPS cells into very early embryos that are capable of forming a placenta but not of fully developing on their own. The resulting embryos were then transferred into the wombs of surrogate mice.
One team of scientists led by Qi Zhou of the Chinese Academy of Sciences created 37 iPS cell lines, three of which produced 27 live offspring, the first of which they named Tiny. One of the offspring, a 7-week-old male, went on to impregnate a female and produce young of its own. Altogether, the researchers bred at least 100 first-generation mice and hundreds of second-generation mice that were nearly identical genetically to the mice from which the iPS cells were derived.
“This gives us hope for future therapeutic interventions using patients’ own reprogrammed cells,” Fanyi Zeng of Shanghai Jiao Tong University, who worked with Zhou, said during a telephone briefing for reporters.
The second group of researchers, led by Shaorong Gao of the National Institute of Biological Sciences in Beijing, created five iPS cell lines, one of which was able to produce embryos that survived until birth. Although four animals were born, only one lived to adulthood. Nevertheless, the work is “proof that iPS cells are functionally equivalent to embryonic stem cells,” Gao said in a telephone interview.
Other researchers agreed, praising the work as a long-awaited confirmation of the cells’ equivalence.
“This clearly says for the first time that iPS cells pass the most stringent test,” said Konrad Hochedlinger, a stem cell researcher at Harvard University.
Opponents of human embryonic stem cell research said the findings provide the latest in a growing body of evidence for why such research is no longer necessary.
“Nobody has been able to find anything that embryonic stem cells can do that these cells can’t do,” said Richard M. Doerflinger of the U.S. Conference of Catholic Bishops. “This was the last remaining barrier.”
The Chinese scientists and others, however, said continued research on embryonic stem cells remains crucial to validate iPS cells and because it remains unclear which cells will turn out to be most useful for different purposes.
But the cells’ ability to produce almost genetically identical offspring raised the fear that rogue scientists might misuse the technique to attempt to clone humans.
“The culture wars are not over,” said Jonathan D. Moreno, a University of Pennsylvania bioethicist. “There was a lot of celebration about the end of the ethical issues with induced pluripotent stem cells. But this is the paradigm case that shows that the old debates are rapidly being transformed into something even more complicated.”
Lanza also raised the prospect that the techniques could one day be used essentially to steal someone’s DNA to make a baby. “With just a little piece of your skin, or some blood from the hospital, anyone could have your child — even an ex-girlfriend or neighbor,” he wrote in an e-mail. “This isn’t rocket science — with a little practice, any IVF clinic in the world could probably figure out how to get it to work.”
In addition, researchers could genetically engineer traits into the cells before using them to create embryos for designer babies.
“For instance, the technology already exists to genetically increase the muscle mass in animals by knocking out a gene known as mystatin, and could be used by a couple who wants a great child athlete,” Lanza wrote.
Others dismissed such concerns, saying many scientific, ethical and regulatory hurdles remain. They said that just because the process works in mice does not necessarily mean it would work in humans, that many states outlaw human cloning and that federal regulators could step in to prevent it.
Sperm From Stem Cells
By Peter Allen, cbsnews.com
This week, British researchers announced another extraordinary breakthrough in medical research. They have taken stem cells from an embryo and created human sperm.
It’s very exciting, said the man who led the team. They have heads, they have tails, and they move. They have all the essential qualities for creating life. The aim, we are told, is to revolutionize the treatment of infertility.
But this discovery has created some interesting dilemmas. Sperm could be produced from female stem cells. That would mean women would no longer need men to create babies. It could also be theoretically used to produce an unlimited supply of babies from one stem cell line — millions of babies who are exactly the same. Will it happen? Probably not. Could it happen? Almost certainly, yes.
One of the opponents of this kind of research called it an example of man at his maddest. There are those who doubt the claims made by these researchers, but the truth is, it is only one of a remarkable series of medical breakthroughs involving stem cells. What these and other researchers are doing is ripping up the codes of law and morality by which we conduct our lives. The pace of discovery has left our legislators floundering.
And to make the whole matter more alarming, the pace of that change is increasing. Take these fine shining teeth, for instance — currently being rebuilt by a top man down the road with the aid of bone implants and titanium bolts. High tech – I said to my dental surgeon. It will soon be out of date, he replied. In future we will grow you nice new teeth from stem cells.
In fact, he said, some people are already trying it. But the rats they are using tend to grow the right teeth in the wrong places. So not quite suitable for me yet.
Stem cells, he said, can grow into anything — not just your teeth, but any failing organ. Think of it. Heart attack? Have a new heart. Kidneys in trouble? Here’s some more. Maybe when the treatments are perfected I will be able to live forever, as will you. Me — here — forever? I suspect for you the proposition does not attract. As a matter of fact it does not do much for me either.
Scientists Reprogram Clearly Defined Adult Cells Into Pluripotent Stem Cells — Directly And Without Viruses
From ScienceDaily.com
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Feds ease restrictions on use of stem cells
By Shankar Vedantam, Washington Post
From SFGate.com
Hundreds of embryonic stem cell lines, whose use in the United States had been curtailed by the Bush administration, can be used to study disorders and develop cures if researchers can show the cells were derived using ethical procedures, according to new rules issued by the federal government Monday.
President Obama had promised during last year’s campaign to ease restrictions on the use of stem cells in research, and has cited the promise of stem cells in finding cures for disorders that have so far proved intractable.
The use of embryonic stem cells was not prohibited under the Bush administration, but federal funds were limited to a very small number of stem cell lines, which choked off most research. The new guidelines, issued by the National Institutes of Health, permit federal funding for research using many of the approximately 700 embryonic stem cell lines that are believed to be in existence.
In a move that drew praise from advocates of stem cell research and bitter criticism from opponents, the NIH said it will allow the use of any existing stem cell line that followed broad ethical principles. Acting NIH Director Raynard Kington said an NIH committee including scientists, ethicists and advocates will evaluate older stem cell lines to assess how each was derived.
He said all embryonic stem cell lines that qualified for federal funding would have to meet a series of ethical requirements: The embryo that was destroyed to create a stem cell line must have been discarded by couples following an in vitro fertilization procedure, and the donors must have been informed that the embryo would be destroyed for stem cell research and made fully cognizant of their choices, including donating the embryo to another couple who want a baby. No donors could have been paid for an embryo, and no threats or inducements could have been used to nudge couples toward donating an embryo.
Kington said the NIH would set up a Web site that would list all the approved stem cell lines.
Almost all of the stem cell lines developed in California are expected to meet the NIH ethics guidelines, said Geoffrey Lomax, senior officer for medical and ethical standards with the California Institute for Regenerative Medicine. The institute was created by a voter initiative in 2004 to support stem cell research.
Lomax said the registry should be a boon to researchers in California by making it easier to use stem cell lines from other states. Previously, scientists would have spent valuable time and money determining whether an out-of-state line met California ethical criteria before they could begin their research. With a national database, they can skip that first step, Lomax said.
“This (registry) will speed things up a bit,” Lomax said. “It creates a level of standardization that is extraordinarily helpful and it removes a lot of uncertainty.”
The use of stem cells in research has become the subject of bitter national controversy, with advocates suggesting it is immoral for the federal government not to fund research that could save thousands of lives, and with opponents arguing it is immoral to fund research that involves destroying embryos.
Chronicle staff writer Erin Allday contributed to this report.
Heart Stem Cells Show Promise
Play CBS Video
From CBSnews.com
Can a human heart repair itself? One heart is trying.
Heart attack patient Ken Milles is the first person ever to get an infusion of his own, laboratory-grown cardiac stem cells. Doctors at the Cedars-Sinai Heart Institute are trying to see if his own heart cells will fix the damaged area of his heart.
Milles is part of a 24-patient clinical trial, designed by Dr. Eduardo Marbán of Cedars-Sinai Heart Institute.
The trial procedure begins when healthy heart cells are collected from the patient’s heart. Next, the cells are off to the lab, where more stem cells are grown, along with complimentary heart cells. These cells then create complex cardiospheres which, Whitaker reported, can actually start beating in the petri dish. Then, doctors insert the lab-grown stem and support cells into the damaged area of the heart, with hopes that patients like Milles will benefit.
In Milles case, doctors hope to repair an area scarred by a heart attack.
If it works in humans as it has in animals, CBS News correspondent Bill Whitaker reports, the scarring caused by the heart attack, will begin to heal, the heart will grow new muscle, pump more blood — and perhaps give the patient a new lease on life.
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Scientists Find Differences in Embryonic Stem Cells and Reprogrammed Skin Cells
From Newswise.com
UCLA researchers have found that embryonic stem cells and skin cells reprogrammed into embryonic-like cells have inherent molecular differences, demonstrating for the first time that the two cell types are clearly distinguishable from one another.
The data from the study suggest that embryonic stem cells and the reprogrammed cells, known as induced pluripotent stem (iPS) cells, have overlapping but still distinct gene expression signatures. The differing signatures were evident regardless of where the cell lines were generated, the methods by which they were derived or the species from which they were isolated, said Bill Lowry, a researcher with the Broad Stem Cell Research Center and a study author.
“We need to keep in mind that iPS cells are not perfectly similar to embryonic stem cells,” said Lowry, an assistant professor of molecular, cell and developmental biology. “We’re not sure what this means with regard to the biology of pluripotent stem cells. At this point our analyses comprise just an observation. It could be biologically irrelevant, or it could be manifested as an advantage or a disadvantage.”
The study appears in the July 2, 2009 issue of the journal Cell Stem Cell.
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