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Stem Cell Research

July 29, 2005 at 12:00 AM EDT
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SUSAN DENTZER: Even for scientists, they’re an odd couple.

JERRY SCHATTEN: So you need to recognize that the primary American contribution to the work in Seoul has been Coca-Cola. Woo Suk lives on caffeine and sugar.

WOO SUK: I love Coca-Cola!

SUSAN DENTZER: Jerry Schatten is a cell biologist and human fertilization expert from the University of Pittsburgh. Woo Suk Hwang is a doctor of veterinary medicine from Seoul National University in South Korea, and now an internationally known trailblazer in the field of embryonic stem cell research.

Two years ago, these two did not even know each other. But now, they say, they’re best friends and close collaborators in embryonic stem cell research.

Embryonic stem cells are prototype cells found in dot-sized, several-day-old embryos like these pictured here. They ultimately develop into the different organs, tissues and cells of the body.

Research on stem cells is controversial, because obtaining the cells and growing them into colonies, or lines, involves dismantling embryos. Schatten says his main goal is to make other scientists in the United States fully aware of Hwang’s astounding research in the field.

JERRY SCHATTEN: I am the sherpa, I am the luggage carrier for you, and the work that you do in Korea doesn’t occur anywhere else in the world.

SUSAN DENTZER: In early 2004, Hwang’s team reported in the journal “Science” that they’d produced a colony of stem cells derived from a cloned human embryo. The embryo was not made through the normal union of egg and sperm. Instead, it was made by taking a woman’s egg cell, stripping out its nucleus and its one set of chromosomes, and then inserting a new nucleus with two sets of chromosomes from another of her body cells.

Then, in May, Hwang and his team reported they’d made 11 new human embryonic stem cell colonies. These cells also came from cloned embryos, but this time the embryos were created with egg cells from one woman and nuclear DNA taken from skin cells of nine different people.

The skin cell donors had a variety of conditions, including a 56-year-old man with a spinal cord injury, a two-year-old boy with a genetic immune disease and a six-year-old girl with juvenile diabetes.

JERRY SCHATTEN: It’s absolutely stunning how brilliant the scientific advances have been and how important the medical implications are.

SUSAN DENTZER: To scientists, the breakthrough was what’s called a proof of principle. It showed human embryonic stem cells could be created that were the exact nuclear genetic match of any individual, male or female, diseased or healthy, regardless of age.

That creates enormous potential for studying how genes influence disease as embryonic stem cells give rise to other body cells and tissues. And down the road, many scientists hope the research could pave the way for so-called regenerative medicine.

That’s also the hope of 38-year-old Danny Heumann, who was paralyzed in an auto accident at age 18. Heumann believes that one day, genetically matched stem cells could be engineered to grow healthy replacement cells to repair his damaged spinal cord.

DANNY HEUMANN: If we give scientists a chance to work with embryonic stem cells, I think the promise for somebody like me to someday maybe get out of my wheelchair — which I call this research the magic bullet — could be a reality.

SUSAN DENTZER: To make certain Hwang’s techniques work, Schatten is now trying to replicate them using monkey cells rather than cells from humans.

The fact that he’s working with animal cells underscores another aspect of their partnership: The way U.S. scientists, like Schatten, who are at the top of their field, are still having to struggle to keep up.

The animal cell stand-ins are made necessary by current U.S. government policy. Four years ago, President George Bush allowed federal funding of human embryonic stem cell research, but only within strict limits. The president spoke about those at a recent White House news conference.

PRESIDENT GEORGE W. BUSH: On August 2001, I set forward a policy to advance stem cell research in a responsible way by funding research on stem cell lines derived only from embryos that had already been destroyed.

SUSAN DENTZER: The policy means that federal funding can only be used for research on 23 authorized stem cell lines, not new ones, like those Hwang’s team created.

The president has reaffirmed his commitment to those limits. He’s vowed to veto legislation recently passed by the U.S. House of Representatives. The bill would allow federal funding for research on new stem cell lines created from embryos discarded from fertility clinics.

Today, in a surprise move, Republican Senate Majority Leader Bill Frist broke with the president and also endorsed the bill.

SEN. BILL FRIST: The limitations that were put in place in 2001 will, over time, slow our ability to bring potential new treatments for certain diseases.

Therefore, I believe the president’s policy should be modified. We should expand federal funding and the accompanying NIH oversight and current guidelines governing stem cell research, carefully and thoughtfully staying within ethical bounds.

SUSAN DENTZER: Amid the battle over federal policy, individual U.S. states have gone in dramatically different directions in setting their own research agendas.

Some, like Indiana, have yielded to opponents’ moral concerns and banned the very procedure that Hwang’s team used to create cloned embryos.

Others, like California, New Jersey, Connecticut and Massachusetts, have expressly authorized state funds for embryonic stem cell research. And some universities, like Harvard, are raising money privately to finance research that can proceed free of the federal restrictions.

Schatten says the result of this uneven patchwork is that human stem cell research is barreling ahead in some places and moving ahead more tentatively in others.

JERRY SCHATTEN: It is so hard to do the scientific and the medical research. When you start overlaying the various potholes and razor wire and hurdles that we have not only in the United States but in our individual states, it’s understandable why our colleagues in South Korea are able to move so much faster than we are.

SUSAN DENTZER: Schatten and Hwang contend that the U.S. should follow Korea in forging a consistent national ethics policy on cloning and stem cell research.

Korea’s law effectively bans the use of cloning aimed at producing a human baby by making it a crime to transfer a cloned embryo into a female uterus. On the other hand, Korea’s law expressly allows and creates ethical guidelines for the cloning of cells for research.

And Hwang contends that the cells he clones are not in fact embryos since they were not created by the normal union of egg and sperm. He calls them instead “nuclear transfer products” and says their probable genetic defects would make it impossible for them to grow into human beings.

WOO SUK HWANG: I think reproductive cloning, cloned human beings, is unethical, and unsafe, and biologically it may be impossible because if we tried to input a nuclear transfer product into the surrogate mother’s womb they never would be a viable human life.

SUSAN DENTZER: Yet these embryos, or transfer products, can clearly produce stem cells, and Schatten says Hwang and his team have practically perfected the process. Now they’re teaching it to scientists across the U.S., such as these here at Stanford University.

WOO SUK HWANG: With the needle still in place, we then lob that pipette against the needle.

SUSAN DENTZER: Hwang says his team’s next goal is to get its stem cells to differentiate into many different types of body cells, mimicking what happens in normal human development.

Meanwhile, unless and until congress overrides the president, any comparable work on new cell lines will proceed as it does now, either in state-funded or privately funded settings in the U.S. or outside the country.