Seeding the World With Stem Cells
Brian Vastag
Previous Vol. 286 No. 1,
July 4, 2001
WashingtonAn Australian team offering embryonic stem cells to academic researchers says that they have been flooded with requests since announcing their plan this spring. More than 50 researchers from across the globe have asked for cells from the team at Monash University in Melbourne, led by Alan Trounson, MD, a professor of obstetrics and gynecology.
The altruistic act is meant to jump-start research that has taken a hit from the uncertain status of National Institutes of Health (NIH) funding, said Trounson's colleague, Martin Pera, PhD. "From the beginning, we've had the view that widespread dissemination [of stem cells] to the academic community at large is essential," said Pera.
Because establishing viable stem cell lines from embryos is tricky, requiring researchers to pluck single cells from days-old embryos at just the right moment, Pera said that it makes sense for a few centers to act as cell banks, allowing other researchers to focus on the biology and therapeutic potential of the cells.
The Monash group becomes the second in the world to establish embryonic stem cell lines. A privately funded University of Wisconsin Medical School spin-off, WiCell, led by James Thomson, PhD, began offering such cells to researchers last year, and they too have received several dozen requests. Thomson said that a group at the University of California, San Francisco, School of Medicine and another in Israel are also close to establishing their own cell lines.
Adding the Monash cells to those already available from WiCell means that embryonic stem cell research can move forward without destroying additional embryos, said Pera. "A lot of people think this research is going to involve the continuing, ongoing destruction of thousands and thousands of embryos. There's no need to envision that at all. We think we've probably made as many cell lines as we need."
In culture, embryonic stem cells divide indefinitely, like biological perpetual motion machines. A single embryo, if handled properly, can spawn millions of pluripotent daughter cells, all genetically identical. The cells achieve immortality by producing the enzyme telomerase, which keeps them young by repairing the telomeres at the tips of each chromosome. In normal cells, the telomeres shrink with each cell division, until after a few dozen replications they reach a stubby stage that triggers cell death. Embryonic stem cells avoid this fate.
This almost magical capacity for unfettered expansion means that enough cells already exist to satisfy demand, said Thomson. "I completely agree with Martin, we have enough for basic research needs. The cell lines are remarkably stable. They can be frozen and thawed multiple times."
At WiCell, master stocks of embryonic stem cells sit frozen in hundreds of vials, chilled by liquid nitrogen. They can be thawed, shipped, or regrown into additional stocks. The center maintains five separate cell lines, each derived from a different embryo, whereas the Monash group maintains six lines. With a 30% to 50% culturing success rate, these 11 strains were derived from about 30 embryos [INLINE] a small number to seed the world.
OPPONENTS CREATE A CHILL
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But that's not how opponents of the research view it. "In a moral sense, it doesn't matter if you kill one, 100, or 1000 embryos," said David Stevens, MD, executive director of the 14 000-member Christian Medical and Dental Association, who regards each embryo, regardless of whether it will ever be implanted in a uterus, as a person. He compared the destruction of embryos to harvesting organs from prisoners, calling both a function of a "utilitarian ethic" that disregards the value of human life.
So far, vocal opponents like Stevens are winning the federal funding battle. Last fall the NIH indicated that it would fund embryonic stem cell research that met certain guidelines, but the Bush administration halted any research funding [INLINE] or even any reviews of research proposals [INLINE] until it completes a legal and scientific review of the NIH guidelines.
In the interim, several stem cell researchers have stepped forward to say that the administration's review, dragging into its sixth month, has had a chilling effect on the entire field. Douglas Melton, PhD, chair of the department of molecular and cell biology at Harvard Medical School, said that the consequences of stem cell politics include "young and old investigators being told to stay away from this area. Damage has been done."
In fact, just three research groups applied to receive NIH funding in this area this spring, a sure sign to Melton and others that researchers are being driven away. "Why would someone invest three months in writing a grant application if they didn't know funding would even materialize?" he said.
This chilling effect has spilled across the oceans all the way to Australia. Because Trounson and Pera wanted to collaborate with researchers in the United States, they tried to ensure that their cells met the NIH guidelines. So, they applied for NIH funding in March, knowing that the first step would be a certification of whether their cells met the NIH rules. When the Department of Health and Human Services (DHHS) halted even this preliminary certification, Pera said he withdrew the grant application.
To satisfy demand for cells, the group is trying to set up a production laboratory with private funding from Embryonic Stem Cell International, a coventure of the Singapore Economic Development Board and a group of Australian investors. Pera said funding talks are under way with Australian health agencies, but nothing is final. (Rules for embryo research vary by state in Australia, with Monash's home state of Victoria providing the most restrictive law. Researchers are forbidden from using or destroying embryos; the cell lines growing at Monash, therefore, were seeded with stem cells gleaned from embryos by researchers at the National University of Singapore.)
While Monash pursues its cell banking facility, a lawsuit filed in US federal court by Thomson, Trounson, Melton, a handful of other stem cell researchers, and actor Christopher Reeve awaits a response from the DHHS. The lawsuit claims that the delay in reviewing stem cell grant applications is illegal and asks to get the process back on track. A spokesman for the DHHS said that he could not comment on pending legal issues, but the department is required to file a brief with the court. The plaintiffs hope that these documents will at least bring to light the internal machinations involved in the review moratorium.
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© 2001 American Medical Association. All rights reserved.
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