Major Advance In Stem-Cell Research

TAKING MATERIAL FROM EMBRYOS POINTS TO PROMISING THERAPIES, ETHICAL PROBLEMS
By Lisa M. Krieger - Mercury News

Posted on Wed, Feb. 11, 2004

For the first time, scientists have cloned a human embryo and grown it to a stage where its stem cells could be
harvested for transplants, an important medical advance that raises political and ethical questions.

The research, reported by South Korean scientists in today's issue of the journal Science, could lead to cures for
Parkinson's disease and juvenile diabetes. But it also raises the specter of producing life only to destroy it for
medical purposes -- and brings science one step closer to creating a cloned baby.

``If it can be replicated elsewhere, it means that we've taken a big step toward creating cells that match the DNA of a
person who needs cell therapy, avoiding rejection problems,'' said law Professor Hank Greely of Stanford University's
Center for Biomedical Ethics.

``The other side,'' added Greely, ``is this: It might be possible to make a baby this way.''

The federal government has banned funding for embryonic stem-cell research in the United States because of ethical
concerns that grow out of the abortion debate, though the research itself is legal and protected in California, Rhode
Island and Louisiana. And a human cloning prohibition bill, which was passed by the House of Representatives a year ago
and is now before the Senate, would punish anyone using this approach with up to 10 years in prison and a minimum fine
of $1 million.

The South Korean scientists report two historic accomplishments. First, they created 30 cloned blastocysts, which are
very young embryos about 100 cells in size. The Massachusetts biotech company Advanced Cell Technology reported in 2001
that it had created the world's first cloned embryos, but they all died within six days.

Second, the South Koreans extracted stem cells from these embryos. One of them was vigorous enough to become a self-
reproducing colony. While stem cells have already been derived from embryos at fertility clinics, these have far more
therapeutic promise.

When isolated, the stem cells began to mature and transform into a variety of cell types.

If these cells could ever be coaxed into becoming specific cells -- say, pancreatic cells needed by diabetics -- they
could be injected into the donor patient without rejection. Because they are cloned and thus share the same DNA as the
donor, they would not be attacked by the body.

``Further improvements are needed before contemplating the use of this technique for cell therapy,'' wrote study leader
Woo Suk Hwang of the Seoul National Laboratory.

Stem cells are the progenitor cells from which all others in the body are derived. Ultimately, scientists hope to use
them to grow many different types of cells.

``The present work has substantially advanced the cause of generating transplantable tissues that exactly match the
patient's own immune system,'' said Roger A. Pedersen, a stem-cell expert formerly of San Francisco and now professor
of regenerative medicine at Addenbrooke's Hospital in Cambridge, England.

Future therapies using these cells would no doubt be expensive and take time. But because they create merely cells,
rather than whole tissues, they are considered feasible.

Before patients could use any stem-cell therapies, approval from the U.S. Food and Drug Administration would be needed.
In 2001, President Bush announced that federal funding for human-embryonic-stem-cell research would be restricted to
work done on cell lines established by that date. Any therapies made using these cells would be limited to patients
with a genetic makeup similar to the donors, because of rejection risk.

``In countries without a deep division about abortion, this research has been much less politically controversial, and
in those places has been allowed to proceed more actively,'' said Stanford's Greely.

There are other problems, as well. It is not known whether these cells, if injected in the body, will settle down in
the right place and do their intended job -- or become another cell type or, even worse, cancer.

Yet another troubling possibility is that stem cells, no matter how intriguing, cannot change the course of underlying
disease. So whatever causes an illness could claim these new cells, as well.

And then there are the ethical issues. ``It is human experimentation,'' said Cheryl Sullenger of the anti-abortion
group Operation Rescue in Wichita, Kan. ``The real problem we have here is they are creating life and then destroying
that life, to benefit some other individual. Why is that right?''

Santa Clara Law School Professor June Carbone said, ``The larger issue is that people see it is a slippery slope -- the
first step towards reproductive cloning, which creates a baby -- which they oppose on moral grounds.''

But for patients, it has huge potential, she said. ``For the diabetic patient who needs cells, and doesn't want to
create a new individual, it is a potential cure.''

Contact Lisa M. Krieger at [log in to unmask] or (408) 920-5565

SOURCE: The San Jose Mercury News, CA
http://www.mercurynews.com/mld/mercurynews/news/local/7933942.htm

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