Will Stem Cells Finally Deliver?

Major breakthroughs are propelling the field. Science becomes medicine.

By David T. Scadden, M.D., and Anthony L. Komaroff, M.D. | NEWSWEEK

Published Dec 6, 2008

From the magazine issue dated Dec 15, 2008

Many diseases involve the death of cells that the body cannot naturally replace. Sometimes cell death comes suddenly, as in a heart attack. Other times it is slow and inexorable, as in Alzheimer's disease. The great promise of stem cells—the body's equivalent of renewable energy—is that they could be coaxed into becoming and then replacing cells lost to disease.

But daunting scientific challenges, ethical concerns and even politics have slowed progress for more than a decade. In the past two years, however, a series of remarkable breakthroughs has advanced the field: suddenly, it appears possible to create cells with all the potential of embryonic stem cells without using embryos, eliminating most of the ethical concerns surrounding stem-cell research.

Embryonic stem cells have two extraordinary properties that make them, potentially, the most medically useful. First, they are "pluripotent," with the capacity to become any type of specialized cell in the body—a heart-muscle cell that pumps blood, an acid-producing cell in the stomach, a cell in the retina of your eye that sees light, or a brain cell that stores memories. Second, embryonic stem cells can keep dividing and making unlimited copies of themselves—an important property, since huge numbers of new cells may be needed to replace cells lost to disease.

Scientists have also been studying adult stem cells, work that doesn't raise the ethical questions posed by em-bryonic-stem-cell research because it doesn't involve the use of human embryos. Bone marrow and organs like the heart and liver all naturally contain adult stem cells. These cells have the potential to develop into most of the cells in their specific organ. Adult stem cells help replace specialized cells that have been killed, since most specialized cells cannot naturally reproduce themselves. However, adult stem cells in most organs cannot naturally repair the massive injury caused by many diseases, although scientists are working on ways to change that. Also, adult stem cells are not pluripotent: unlike embryonic stem cells, they cannot be turned into any cell in the body.

Such cells also raise ethical questions, since some people believe an embryo with the potential to be implanted and develop into a baby has the moral status of a person and should not be destroyed, no matter how great the human benefit. In 2001, President George W. Bush restricted federal funding to existing lines of embryonic stem cells; government money could not be used for research that involved the further destruction of embryos.

A possible solution to these daunting obstacles came from a team of Japanese researchers who asked a simple, if fanciful, question: is it possible to turn a specialized cell back into an embryonic stem cell, or at least into a cell with the same remarkable properties as an embryonic stem cell? It's the genes within every cell that determine how that cell acts and looks. While all of our specialized cells and our embryonic stem cells share exactly the same set of genes, very different genes are "turned on" in each type of cell. In other words, an embryonic stem cell turns into a specialized cell because certain genes are turned on, and others turned off.
Cont.

http://www.newsweek.com/id/172563

Related:

Tuesday, March 3, 2009

Embryonic Stem Cell Therapy; Panacea or False Promise?

While remaining sensitive to the ethical concerns raised by the destruction of day old human embryos, scientists have long viewed embryonic stem cell research as perhaps the best hope for finding cures for debilitating diseases such as Alzheimer's and Parkinson's. But the inconvenient fact that human beings had to be conceived in order to furnish these stem cells was no deterrent to high profile likely beneficiaries and their families and advocacy groups.

When Christopher Reeve was paralized in a fall from a horse, he and his family became very vocal. Michael J Fox who became afflicted with Parkinson's Disease at a very young age was extremely critical of the Bush administration over this issue. Much of the subsequent Bush derangement existing in this country was fueled by Hollywood celebrities resentment of George Bush's stance on embryonic stem cell research.

Nancy Reagan was sure her husband's Alzheimer's Disease could be cured if only the bully George Bush did not stand in the way. The agony of these sufferers is easily understood. They felt Bush and Bush alone was denying the panacea of a host of diseases. Their attitude now seems quite unjustified in the face of the barriers that exist and may never be breached.

Boy gets tumor from embryonic stem-cell injection

Charlie Butts and Marty Cooper - OneNewsNow - 2/27/2009 7:00:00 AM

Medical Research Israel reports negative results from experimental use of fetal stem cells.

According to The Associated Press, an Israeli family hoped to save their son from a lethal brain disease and received injections of embryonic stem cells. The injections caused tumors to grow in his brain and spinal cord.

The Public Library of Science notes this is the first documented case of a human getting a brain tumor after embryonic stem-cell therapy, even though the tumor is slow-growing and benign. A team of scientists at Tel Aviv University tested the tumor tissue and confirmed it was the embryonic cells.

Dr. David Stevens of the Christian Medical & Dental Association notes that other people are traveling to other countries for treatments using embryonic or fetal stem cells and ending up with worsened conditions.

"They definitely are experiments, and these are desperate people being preyed upon by people trying to sell miracle cures," he explains. "Unfortunately that same approach is being used to sell this whole line of embryonic stem-cell research to the American people, promising miracle cures if we'll just fund this type of research."

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