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Stem Cell Hype Flows Both Ways
By Dr. Lee Silver
Scientists working at Novocell, Inc. in San Diego, CA have reported a stunning advance in the race to move embryonic stem cells from the province of basic scientific research into the arena of clinical trials for patients suffering from diabetes. Type I diabetes results from the degeneration of specialized cells in the pancreas (called beta-cells) that produce the hormone insulin. In healthy individuals, a rise in blood sugar after a meal induces beta-cells to secrete insulin, which enables other cells to absorb and utilize the sugar as fuel; when blood sugar levels drop, insulin production is turned down. In diabetics, insulin regulation fails. Currently, patients suffering from this disease have no choice but to constantly monitor blood sugar levels and take insulin shots when those levels rise.
Just a decade ago, it would have been ludicrous to suggest that research in cellular and molecular biology might lead to the development of a laboratory protocol for creating a substitute pancreas that could be implanted into diabetic patients. And yet, the results reported by Emmanuel Baetge and his team at Novocell in the journal _Nature Biotechnology_ suggest that what was once a pipe-dream may soon be a reality -- a long-lasting treatment for diabetes achieved through the use of embryonic stem cells.
Embryonic stem (ES) cells occur naturally within the one-week old human embryo. During normal development not many ES cells are formed, and none stay "embryonic-like" very long. They grow and divide over a few weeks into a variety of more specialized cells that eventually differentiate into every tissue and organ in the adult body. In 1998, however, James Thomson mastered the technology required to isolate ES cells and keep them dividing indefinitely without differentiating in petri dishes. The promise and potential power of ES cell technology lies with scientists uncovering specific molecular signals that would channel ES cells to develop into just a single tissue, which could be used to treat a particular disease.
The key to the success of the Novocell team was not to go for the gold all at once, but to carefully mimic the natural step-by-step process by which a subset of cells in a human embryo become gradually transformed into a pancreas. This process is driven by a timed sequence of particular genes turning on and off. Baetge and his colleagues recapitulated the entire process in a petri dish, starting with isolated ES cells and channeling them through a series of four intermediate stages, over a two-week period, prior to a final transformation into pancreatic tissue that produces insulin in quantities similar to that produced in a healthy pancreas. Since none of the intermediate stages of pancreatic development survive inside an adult body, the protocol appears absolutely dependent on starting with ES cells, rather than any conceivable adult cell.
The Novocell team is not yet home free. So far, they have produced fetal-like pancreatic tissue that is not responsive to changes in sugar levels. The protocol must be extended one more stage to produce fully functional adult cells. Baetge is confident that this goal will be achieved within the next year. If all goes as planned, he says, clinical trials could begin as early as 2009. At the end of their publication, Baetge and colleagues write, "We are awed by the capacity of hES cells to recapitulate development ex vivo and are optimistic that these unique cells will ultimately represent a renewable source of pancreatic beta-cells for people with diabetes."
In the brief time since human ES cells were first isolated, many opponents of the research have argued vociferously that the potential of this line of research for creating novel therapies has been hyped by scientists. Indeed, even research supporters have been cowed into a hyper-cautious mode, agreeing that it might be decades before the technology provides treatments for common diseases. The Novocell team ignored all of this pessimism and got on with the job. In doing so, they showed that hype can flow both ways.
Lee Silver, Ph.D., is a professor of molecular biology and public affairs at Princeton and an ACSH Trustee. He was recently criticized by fellow Princeton professor Robert P. George and bioethicist Patrick Lee, who object to embryonic stem cell research, on NationalReview.com, and Silver wrote a response. A measure related to the divisive issue will be voted on in Missouri next week.
LGK (November 2, 2006)
Debating the benefits, or lack thereof, of embryonic stem cell (ESC) research is a red herring, no matter which side uses it. Whether or not benefits are to be had is irrelevant. We all share total disdain for the likes of the infamous Dr. Mengele’s “research,” thus we all acknowledge that ends alone do not justify means. The entire ESC research debate boils down to a singular assertion: Embryos are not people, they are merely tissue. However, since the origins and mechanisms of human self-awareness have thus far proven to be beyond the reach of science to explain, science justly cannot claim the right to define whether a human embryo should or should not be granted the same respect that we grant to those of us who have already taken our first breath. Having said that, I will grant that the overwhelming majority of ideas put forth by religious leaders throughout human history concerning those origins and mechanisms are pure fiction and baseless opinion. Yet there is truth hidden amongst that fiction. Those who have experienced first-hand, one-on-one communication with our Maker, and who have learned to leverage that communication to discern truths from falsehoods, know that our lives have purpose and meaning, know that pain and death are part of life, know that we continue an existence after death, and know that there is an accounting made by our Maker both for the pains we have suffered and the harms we have caused. I urge any who would propose to create and/or destroy human embryos for research to first find out for themselves God’s Will concerning the matter, and to find it out through personal, one-on-one communication with the only source that can be trusted: God.
Becky Fenger (November 2, 2006)
LGK misses the entire point. Dr. Lee Silver is reporting on the distinct possibility that within a year there might be a long-lasting treatment for diabetes through the use of embryonic stem cells. A talking point for those who would forbid embryonic stem cell research is that such work is not promising and would be decades away from fruition. This achievement would shatter that argument. It would be very useful if "those who have experienced first-hand, one-on-one communication with our Maker"--- as described by LGK--- would come back from the dead and give us God's take on the subject. And sooner rather than later.
LGK (November 5, 2006)
Becky, Dr. Silver’s article is indeed a very cogent counterpoint to assertions by opponents of ESC research assert that, as you put it, “such work is not promising and would be decades away from fruition.” Dr. Silver’s point is perfectly clear to me. Let me restate my point: There are matters that justly are the purview of science, and matters that justly are the purview of religion. I assert that ESC research is a debate about the boundaries between those two, not a debate about whether we can use ESC to cure illnesses. Judging from your ridicule, I must admit that my closing point was not clear enough so I will clarify: Our Maker not only hears the prayers of *living mortals,* but answers them. One only has to learn how to hear, and then practice it. Lest you mistake me for someone who eschews science, I am a mechanical engineer. I am also a lay minister. Thus I have a vested interest in asking where the boundaries between science and religion should be drawn.
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